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Advanced Design System 201101 - WLAN Design Library
1
Advanced Design System 201101
Feburary 2011WLAN Design Library
Advanced Design System 201101 - WLAN Design Library
2
copy Agilent Technologies Inc 2000-20115301 Stevens Creek Blvd Santa Clara CA 95052 USANo part of this documentation may be reproduced in any form or by any means (includingelectronic storage and retrieval or translation into a foreign language) without prioragreement and written consent from Agilent Technologies Inc as governed by UnitedStates and international copyright laws
AcknowledgmentsMentor Graphics is a trademark of Mentor Graphics Corporation in the US and othercountries Mentor products and processes are registered trademarks of Mentor GraphicsCorporation Calibre is a trademark of Mentor Graphics Corporation in the US and othercountries Microsoftreg Windowsreg MS Windowsreg Windows NTreg Windows 2000reg andWindows Internet Explorerreg are US registered trademarks of Microsoft CorporationPentiumreg is a US registered trademark of Intel Corporation PostScriptreg and Acrobatregare trademarks of Adobe Systems Incorporated UNIXreg is a registered trademark of theOpen Group Oracle and Java and registered trademarks of Oracle andor its affiliatesOther names may be trademarks of their respective owners SystemCreg is a registeredtrademark of Open SystemC Initiative Inc in the United States and other countries and isused with permission MATLABreg is a US registered trademark of The Math Works IncHiSIM2 source code and all copyrights trade secrets or other intellectual property rightsin and to the source code in its entirety is owned by Hiroshima University and STARCFLEXlm is a trademark of Globetrotter Software Incorporated Layout Boolean Engine byKlaas Holwerda v17 httpwwwxs4allnl~kholwerdboolhtml FreeType ProjectCopyright (c) 1996-1999 by David Turner Robert Wilhelm and Werner LembergQuestAgent search engine (c) 2000-2002 JObjects Motif is a trademark of the OpenSoftware Foundation Netscape is a trademark of Netscape Communications CorporationNetscape Portable Runtime (NSPR) Copyright (c) 1998-2003 The Mozilla Organization Acopy of the Mozilla Public License is at httpwwwmozillaorgMPL FFTW The FastestFourier Transform in the West Copyright (c) 1997-1999 Massachusetts Institute ofTechnology All rights reserved
The following third-party libraries are used by the NlogN Momentum solver
This program includes Metis 40 Copyright copy 1998 Regents of the University ofMinnesota httpwwwcsumnedu~metis METIS was written by George Karypis(karypiscsumnedu)
Intel Math Kernel Library httpwwwintelcomsoftwareproductsmkl
SuperLU_MT version 20 - Copyright copy 2003 The Regents of the University of Californiathrough Lawrence Berkeley National Laboratory (subject to receipt of any requiredapprovals from US Dept of Energy) All rights reserved SuperLU Disclaimer THISSOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS AS ISAND ANY EXPRESS OR IMPLIED WARRANTIES INCLUDING BUT NOT LIMITED TO THEIMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSEARE DISCLAIMED IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BELIABLE FOR ANY DIRECT INDIRECT INCIDENTAL SPECIAL EXEMPLARY ORCONSEQUENTIAL DAMAGES (INCLUDING BUT NOT LIMITED TO PROCUREMENT OFSUBSTITUTE GOODS OR SERVICES LOSS OF USE DATA OR PROFITS OR BUSINESSINTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY WHETHER INCONTRACT STRICT LIABILITY OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE EVEN IF ADVISED OF THEPOSSIBILITY OF SUCH DAMAGE
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7-zip - 7-Zip Copyright Copyright (C) 1999-2009 Igor Pavlov Licenses for files are7zdll GNU LGPL + unRAR restriction All other files GNU LGPL 7-zip License This libraryis free software you can redistribute it andor modify it under the terms of the GNULesser General Public License as published by the Free Software Foundation eitherversion 21 of the License or (at your option) any later version This library is distributedin the hope that it will be usefulbut WITHOUT ANY WARRANTY without even the impliedwarranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE See the GNULesser General Public License for more details You should have received a copy of theGNU Lesser General Public License along with this library if not write to the FreeSoftware Foundation Inc 59 Temple Place Suite 330 Boston MA 02111-1307 USAunRAR copyright The decompression engine for RAR archives was developed using sourcecode of unRAR programAll copyrights to original unRAR code are owned by AlexanderRoshal unRAR License The unRAR sources cannot be used to re-create the RARcompression algorithm which is proprietary Distribution of modified unRAR sources inseparate form or as a part of other software is permitted provided that it is clearly statedin the documentation and source comments that the code may not be used to develop aRAR (WinRAR) compatible archiver 7-zip Availability httpwww7-ziporg
AMD Version 22 - AMD Notice The AMD code was modified Used by permission AMDcopyright AMD Version 22 Copyright copy 2007 by Timothy A Davis Patrick R Amestoyand Iain S Duff All Rights Reserved AMD License Your use or distribution of AMD or anymodified version of AMD implies that you agree to this License This library is freesoftware you can redistribute it andor modify it under the terms of the GNU LesserGeneral Public License as published by the Free Software Foundation either version 21 ofthe License or (at your option) any later version This library is distributed in the hopethat it will be useful but WITHOUT ANY WARRANTY without even the implied warranty ofMERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE See the GNU LesserGeneral Public License for more details You should have received a copy of the GNULesser General Public License along with this library if not write to the Free SoftwareFoundation Inc 51 Franklin St Fifth Floor Boston MA 02110-1301 USA Permission ishereby granted to use or copy this program under the terms of the GNU LGPL providedthat the Copyright this License and the Availability of the original version is retained onall copiesUser documentation of any code that uses this code or any modified version ofthis code must cite the Copyright this License the Availability note and Used bypermission Permission to modify the code and to distribute modified code is grantedprovided the Copyright this License and the Availability note are retained and a noticethat the code was modified is included AMD Availabilityhttpwwwciseufleduresearchsparseamd
UMFPACK 502 - UMFPACK Notice The UMFPACK code was modified Used by permissionUMFPACK Copyright UMFPACK Copyright copy 1995-2006 by Timothy A Davis All RightsReserved UMFPACK License Your use or distribution of UMFPACK or any modified versionof UMFPACK implies that you agree to this License This library is free software you canredistribute it andor modify it under the terms of the GNU Lesser General Public Licenseas published by the Free Software Foundation either version 21 of the License or (atyour option) any later version This library is distributed in the hope that it will be usefulbut WITHOUT ANY WARRANTY without even the implied warranty of MERCHANTABILITYor FITNESS FOR A PARTICULAR PURPOSE See the GNU Lesser General Public License formore details You should have received a copy of the GNU Lesser General Public Licensealong with this library if not write to the Free Software Foundation Inc 51 Franklin StFifth Floor Boston MA 02110-1301 USA Permission is hereby granted to use or copy thisprogram under the terms of the GNU LGPL provided that the Copyright this License andthe Availability of the original version is retained on all copies User documentation of any
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code that uses this code or any modified version of this code must cite the Copyright thisLicense the Availability note and Used by permission Permission to modify the codeand to distribute modified code is granted provided the Copyright this License and theAvailability note are retained and a notice that the code was modified is includedUMFPACK Availability httpwwwciseufleduresearchsparseumfpack UMFPACK(including versions 221 and earlier in FORTRAN) is available athttpwwwciseufleduresearchsparse MA38 is available in the Harwell SubroutineLibrary This version of UMFPACK includes a modified form of COLAMD Version 20originally released on Jan 31 2000 also available athttpwwwciseufleduresearchsparse COLAMD V20 is also incorporated as a built-infunction in MATLAB version 61 by The MathWorks Inc httpwwwmathworkscom COLAMD V10 appears as a column-preordering in SuperLU (SuperLU is available athttpwwwnetliborg ) UMFPACK v40 is a built-in routine in MATLAB 65 UMFPACK v43is a built-in routine in MATLAB 71
Qt Version 463 - Qt Notice The Qt code was modified Used by permission Qt copyrightQt Version 463 Copyright (c) 2010 by Nokia Corporation All Rights Reserved QtLicense Your use or distribution of Qt or any modified version of Qt implies that you agreeto this License This library is free software you can redistribute it andor modify it undertheterms of the GNU Lesser General Public License as published by the Free SoftwareFoundation either version 21 of the License or (at your option) any later version Thislibrary is distributed in the hope that it will be usefulbut WITHOUT ANY WARRANTY without even the implied warranty of MERCHANTABILITYor FITNESS FOR A PARTICULAR PURPOSE See the GNU Lesser General Public License formore details You should have received a copy of the GNU Lesser General Public Licensealong with this library if not write to the Free Software Foundation Inc 51 Franklin StFifth Floor Boston MA 02110-1301 USA Permission is hereby granted to use or copy thisprogram under the terms of the GNU LGPL provided that the Copyright this License andthe Availability of the original version is retained on all copiesUserdocumentation of any code that uses this code or any modified version of this code mustcite the Copyright this License the Availability note and Used by permissionPermission to modify the code and to distribute modified code is granted provided theCopyright this License and the Availability note are retained and a notice that the codewas modified is included Qt Availability httpwwwqtsoftwarecomdownloads PatchesApplied to Qt can be found in the installation at$HPEESOF_DIRprodlicensesthirdpartyqtpatches You may also contact BrianBuchanan at Agilent Inc at brian_buchananagilentcom for more information
The HiSIM_HV source code and all copyrights trade secrets or other intellectual propertyrights in and to the source code is owned by Hiroshima University andor STARC
Errata The ADS product may contain references to HP or HPEESOF such as in filenames and directory names The business entity formerly known as HP EEsof is now partof Agilent Technologies and is known as Agilent EEsof To avoid broken functionality andto maintain backward compatibility for our customers we did not change all the namesand labels that contain HP or HPEESOF references
Warranty The material contained in this document is provided as is and is subject tobeing changed without notice in future editions Further to the maximum extentpermitted by applicable law Agilent disclaims all warranties either express or impliedwith regard to this documentation and any information contained herein including but notlimited to the implied warranties of merchantability and fitness for a particular purposeAgilent shall not be liable for errors or for incidental or consequential damages in
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connection with the furnishing use or performance of this document or of anyinformation contained herein Should Agilent and the user have a separate writtenagreement with warranty terms covering the material in this document that conflict withthese terms the warranty terms in the separate agreement shall control
Technology Licenses The hardware andor software described in this document arefurnished under a license and may be used or copied only in accordance with the terms ofsuch license Portions of this product include the SystemC software licensed under OpenSource terms which are available for download at httpsystemcorg This software isredistributed by Agilent The Contributors of the SystemC software provide this softwareas is and offer no warranty of any kind express or implied including without limitationwarranties or conditions or title and non-infringement and implied warranties orconditions merchantability and fitness for a particular purpose Contributors shall not beliable for any damages of any kind including without limitation direct indirect specialincidental and consequential damages such as lost profits Any provisions that differ fromthis disclaimer are offered by Agilent only
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11a Receivers 9 WLAN_80211a_RF_RxFSync 10 WLAN_80211a_RF_RxNoFSync 13 WLAN_80211a_RF_Rx_Soft 16 WLAN_80211aRxFSync 20 WLAN_80211aRxFSync1 24 WLAN_80211aRxNoFSync 27 WLAN_80211aRxNoFSync1 29 WLAN_80211aRx_Soft 32 WLAN_BurstSync 35 WLAN_ChEstimator 37 WLAN_FineFreqSync 39 WLAN_FreqSync 41 WLAN_OFDMEqualizer 43 WLAN_PhaseEst 44 WLAN_PhaseTrack 45 WLAN_RmvNullCarrier 47
11b Receivers 49 WLAN_11bBurstRec 50 WLAN_11bBurstSync 53 WLAN_11bCIREstimator 55 WLAN_11bDemuxBurst 57 WLAN_11bDescrambler 60 WLAN_11bDFE 62 WLAN_11b_Equalizer 66 WLAN_11bFreqEstimator 70 WLAN_11bPreamble 72 WLAN_11bRake 74 WLAN_11b_Rake 76 WLAN_CCKDemod 79 WLAN_CCK_RF_Rx_DFE 80 WLAN_CCK_RF_Rx_Rake 84 WLAN_CCK_Rx_DFE 88 WLAN_CCK_Rx_Rake 92 WLAN_Despreader 95 WLAN_FcCompensator 97 WLAN_HeaderDemap 100 WLAN_PhaseRotator 102 WLAN_PrmblDemap 105 WLAN_RecFilter 107
11b Signal Sources 109 WLAN_11bCCK_RF 110 WLAN_11bCCKSignalSrc 116 WLAN_11bCCKSignalSrc1 120 WLAN_11bMuxBurst 124 WLAN_11bPBCCSignalSrc 127 WLAN_11bScrambler 131 WLAN_11SignalSrc 133 WLAN_802_11bRF 137 WLAN_Barker 143 WLAN_CCKMod 144 WLAN_CRC 147 WLAN_HeaderMap 149 WLAN_IdlePadding 151
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WLAN_MuxPLCP 152 WLAN_PBCCConvCoder 154 WLAN_PBCCMod 156 WLAN_PLCPHeader 158 WLAN_PLCPPreamble 161 WLAN_PreambleMap 163 WLAN_PSDUMap 165 WLAN_TransFilter 167
80211a Signal Sources 170 WLAN_802_11aRF 171 WLAN_80211a_RF 177 WLAN_80211a_RF_WithPN 183 WLAN_80211aSignalSrc 189 WLAN_80211aSignalSrc1 192 WLAN_DATA 195 WLAN_ExtrPSDU 198 WLAN_LPreambleGen 200 WLAN_PSDU 201 WLAN_SIGNAL 203 WLAN_SPreambleGen 205 WLAN_Tail 207
About WLAN Design Library 209 Agilent Instrument Compatibility 210 WLAN Systems 211 Component Libraries 214 Glossary of Terms 219 References 220
Channel and Channel Coding Components 221 WLAN_11aConvDecoder 222 WLAN_ConvCoder 225 WLAN_ConvDecoder 227 WLAN_Deinterleaver 230 WLAN_Interleaver 232 WLAN_PuncCoder 234 WLAN_PuncCoderP1 236 WLAN_PuncConvCoder 237 WLAN_PuncDecoder 239 WLAN_PuncDecoder1 241 WLAN_PuncDecoderP1 243 WLAN_Scrambler 244
Measurements for WLAN Design Library 246 WLAN_80211a_BERPER 247 WLAN_80211a_Constellation 249 WLAN_80211a_EVM 251 WLAN_80211a_RF_EVM 257 WLAN_DSSS_CCK_PBCC_EVM 260
Modulation Components 266 WLAN_BPSKCoder 267 WLAN_BPSKDecoder 268 WLAN_Demapper 269 WLAN_Mapper 271 WLAN_QAM16Coder 274 WLAN_QAM16Decoder 276 WLAN_QAM64Coder 277
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WLAN_QAM64Decoder 279 WLAN_QPSKCoder 280 WLAN_QPSKDecoder 281 WLAN_SoftDemappe 281
Multiplex Components for WLAN Design Library 285 WLAN_BurstOut 286 WLAN_BurstReceiver 288 WLAN_CommCtrl2 290 WLAN_CommCtrl3 291 WLAN_CosRollWin 292 WLAN_DemuxBurst 294 WLAN_DemuxBurstNF 297 WLAN_DemuxOFDMSym 300 WLAN_DemuxSigData 302 WLAN_DistCtrl2 304 WLAN_DistCtrl3 305 WLAN_H2CosRollWin 306 WLAN_H2MuxOFDMSym 308 WLAN_InsertZero 310 WLAN_LoadIFFTBuff 311 WLAN_MuxBrdBurst 312 WLAN_MuxBurst 316 WLAN_MuxBurstNW 318 WLAN_MuxDataChEst 320 WLAN_MuxDiBurst 322 WLAN_MuxDLBurst 325 WLAN_MuxOFDMSym 328 WLAN_MuxSigData 331 WLAN_MuxULBurstL 333 WLAN_MuxULBurstS 336
Test Components for WLAN Design Library 339 WLAN_BERPER 340 WLAN_EVM 342 WLAN_RF_CCDF 344 WLAN_RF_PowMeas 346
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11a ReceiversWLAN 80211a RF RxFSync (wlan)WLAN 80211a RF RxNoFSync (wlan)WLAN 80211a RF Rx Soft (wlan)WLAN 80211aRxFSync (wlan)WLAN 80211aRxFSync1 (wlan)WLAN 80211aRxNoFSync (wlan)WLAN 80211aRxNoFSync1 (wlan)WLAN 80211aRx Soft (wlan)WLAN BurstSync (wlan)WLAN ChEstimator (wlan)WLAN FineFreqSync (wlan)WLAN FreqSync (wlan)WLAN OFDMEqualizer (wlan)WLAN PhaseEst (wlan)WLAN PhaseTrack (wlan)WLAN RmvNullCarrier (wlan)
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WLAN_80211a_RF_RxFSync
Description Receiver of IEEE 80211a with full frequency synchronizationLibrary WLAN ReceiverClass TSDFWLAN_80211a_RF_RxFSyncDerived From WLAN_ReceiverBase
Parameters
Name Description Default Unit Type Range
RIn input resistance DefaultRIn Ohm real (0 infin)
ROut output resistance DefaultROut Ohm real (0 infin)
RTemp physical temperature in degrees C DefaultRTemp real [-27315infin)
GainImbalance gain imbalance in dB Q channel relative to I channel 00 real (-infin infin)
PhaseImbalance phase imbalance in degrees Q channel relative to Ichannel
00 real (-infin infin)
RefFreq internal reference frequency 5200MHz Hz real (0 infin)
Sensitivity voltage output sensitivity VoutVin 1 real (-infin infin)
Phase reference phase in degrees 00 deg real (-infin infin)
Length octet number of PSDU 256 int [1 4095]
Rate data rate Mbps_6 Mbps_9 Mbps_12 Mbps_18Mbps_24 Mbps_27 Mbps_36 Mbps_48 Mbps_54
Mbps_6 enum
Order FFT points=2^Order 6 int [6 11]
ScramblerInit initial state of scrambler 1 0 1 1 1 0 1 intarray
0 1dagger
GuardType type of guard interval T2 T4 T8 T16 T32UserDefined
T4 enum
GuardInterval guard interval defined by user 16 int [0 2Order ]
TSYM one OFDM symbol interval 4e-6 sec real (0 infin)
Idle padded number of zeros between two bursts 0 int [0 infin)
FreqOffset actual frequency offset 00 Hz real (-infin infin)
dagger for each array element array size must be 7
Pin Inputs
Pin Name Description Signal Type
1 RF_Signal RF signals timed
Pin Outputs
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Pin Name Description Signal Type
2 For_EVM undemapped signal after FFT used forEVM
complex
3 UnDecodedBits deinterleaved data bits before decoding real
4 PSDU PSDU bits int
5 SIGNAL SIGNAL int
NotesEquations
This WLAN receiver provides full frequency synchronization according to the IEEE180211a Standard it can be configured in a top-level design using modelparametersThis subnetwork integrates an RF demodulator and baseband receiver The schematicis shown in the following figure
WLAN_80211a_RF_RxFSync Schematic
Receiver functions are implemented as specified in the IEEE 80211a Standard2Start of frame is detectedThe transition from short to channel estimation sequences is detected and time(with one sample resolution) is established (burst synchronization)Coarse and fine frequency offsets are estimatedThe packet is derotated according to estimated frequency offset (coarse and finefrequency synchronization)Complex channel response coefficients are estimated for each subcarrier(channel estimation)Each data OFDM symbol is transformed into subcarrier received values pilotsubcarrier phases are estimated subcarrier values are derotated according toestimated phase and each subcarrier value is divided with a complex estimatedchannel response coefficient (phase tracking phase synchronization andequalization)The equalized signal is demultiplexed into SIGNAL and PSDU partsSIGNAL and PSDU are demapped deinterleaved and decoded respectivelyDemodulated SIGNAL and PSDU bits are outputThe equalized receiver signal is output for EVM measurementThe deinterleaved PSDU signal is output which is the signal before decoding
The WLAN_80211aRxFSync1 receiver schematic is shown in the following figure
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WLAN_80211aRxFSync1 Schematic
References
IEEE Standard 80211a-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer in the 5 GHzBand 1999
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WLAN_80211a_RF_RxNoFSync
Description Receiver of IEEE 80211a without frequency synchronizationLibrary WLAN ReceiverClass TSDFWLAN_80211a_RF_RxNoFSyncDerived From WLAN_ReceiverBase
Parameters
Name Description Default Unit Type Range
RIn input resistance DefaultRIn Ohm real (0 infin)
ROut output resistance DefaultROut Ohm real (0 infin)
RTemp physical temperature in degrees C DefaultRTemp real [-27315infin)
GainImbalance gain imbalance in dB Q channel relative to I channel 00 real (-infin infin)
PhaseImbalance phase imbalance in degrees Q channel relative to Ichannel
00 real (-infin infin)
RefFreq internal reference frequency 5200MHz Hz real (0 infin)
Sensitivity voltage output sensitivity VoutVin 1 real (-infin infin)
Phase reference phase in degrees 00 deg real (-infin infin)
Length octet number of PSDU 256 int [1 4095]
Rate data rate Mbps_6 Mbps_9 Mbps_12 Mbps_18Mbps_24 Mbps_27 Mbps_36 Mbps_48 Mbps_54
Mbps_6 enum
Order FFT points=2^Order 6 int [6 11]
ScramblerInit initial state of scrambler 1 0 1 1 1 0 1 intarray
0 1dagger
GuardType type of guard interval T2 T4 T8 T16 T32UserDefined
T4 enum
GuardInterval guard interval defined by user 16 int [0 2Order ]
Idle padded number of zeros between two bursts 0 int [0 infin)
dagger for each array element array size must be 7
Pin Inputs
Pin Name Description Signal Type
1 RF_Signal RF signals timed
Pin Outputs
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Pin Name Description Signal Type
2 For_EVM undemapped signal after FFT used forEVM
complex
3 UnDecodedBits deinterleaved data bits before decoding real
4 PSDU PSDU bits int
5 SIGNAL SIGNAL int
NotesEquations
This WLAN receiver without frequency synchronization is according to the IEEE180211a Standard it can be configured in a top-level design using modelparametersThis subnetwork integrates an RF demodulator and baseband receiver The schematicis shown in the following figure
WLAN_80211a_RF_RxNoFSync Schematic
Receiver functions are implemented as specified in the IEEE 80211a Standard
Start of frame is detectedThe transition from short to channel estimation sequences is detected and time(with one sample resolution) is established (burst synchronization)Complex channel response coefficients are estimated for each subcarrier(channel estimation)Each data OFDM symbol will be transformed into subcarrier received valuespilot subcarrier phases will be estimated subcarrier values will be derotatedaccording to estimated phase and each subcarrier value will be divided with acomplex estimated channel response coefficient (phase tracking phasesynchronization and equalization)The equalized signal is demultiplexed into SIGNAL and PSDU partsSIGNAL and PSDU are demapped deinterleaved and decoded respectivelyDemodulated SIGNAL and PSDU bits are outputThe equalized receiver signal is output for EVM measurementThe deinterleaved PSDU signal is output which is the signal before decoding
The WLAN_80211aRxNoFSync1 schematic is shown in the following figure
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WLAN_80211aRxNoFSync1 Schematic
References
IEEE Standard 80211a-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer in the 5 GHzBand 1999
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WLAN_80211a_RF_Rx_Soft
Description Receiver of IEEE 80211a with full frequency synchronizationLibrary WLAN ReceiverClass TSDFWLAN_80211a_RF_Rx_SoftDerived From WLAN_ReceiverBase
Parameters
Name Description Default Unit Type Range
RIn input resistance DefaultRIn Ohm real (0 infin)
ROut output resistance DefaultROut Ohm real (0 infin)
RTemp physical temperature in degrees C DefaultRTemp real [-27315infin)
GainImbalance gain imbalance in dB Q channel relative to I channel 00 real (-infin infin)
PhaseImbalance phase imbalance in degrees Q channel relative to Ichannel
00 real (-infin infin)
RefFreq internal reference frequency 5200MHz Hz real (0 infin)
Sensitivity voltage output sensitivity VoutVin 1 real (-infin infin)
Phase reference phase in degrees 00 deg real (-infin infin)
Length octet number of PSDU 256 int [1 4095]
Rate data rate Mbps_6 Mbps_9 Mbps_12 Mbps_18Mbps_24 Mbps_27 Mbps_36 Mbps_48 Mbps_54
Mbps_6 enum
Order FFT points=2^Order 6 int [6 11]
ScramblerInit initial state of scrambler 1 0 1 1 1 0 1 intarray
0 1dagger
GuardType type of guard interval T2 T4 T8 T16 T32UserDefined
T4 enum
GuardInterval guard interval defined by user 16 int [0 2Order ]
TSYM one OFDM symbol interval 4e-6 sec real (0 infin)
Idle padded number of zeros between two bursts 0 int [0 infin)
DecoderType demapping type Hard Soft CSI CSI enum
TrunLen path memory truncation length 60 int [20 200]
FreqOffset actual frequency offset 00 Hz real (-infin infin)
dagger for each array element array size must be 7
Pin Inputs
Pin Name Description Signal Type
1 RF_Signal RF signals timed
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Pin Outputs
Pin Name Description Signal Type
2 For_EVM undemapped signal after FFT used forEVM
complex
3 UnDecodedBits deinterleaved data bits before decoding real
4 PSDU PSDU bits int
5 SIGNAL SIGNAL int
NotesEquations
This WLAN receiver provides full-frequency synchronization according to the IEEE180211a Standard It can be configured in a top-level design using modelparametersThis subnetwork integrates an RF demodulator and baseband receiver The schematicis shown in the following figure
WLAN_80211a_RF_Rx_Soft Schematic
Receiver functions are implemented as specified in the IEEE 80211a Standard2Start of frame is detectedThe transition from short to channel estimation sequences is detected and time(with one sample resolution) is established (burst synchronization)Coarse and fine frequency offsets are estimatedThe packet is derotated according to estimated frequency offset (coarse and finefrequency synchronization)Complex channel response coefficients are estimated for each subcarrier(channel estimation)Each data OFDM symbol is transformed into subcarrier received values pilotsubcarrier phases are estimated subcarrier values are derotated according toestimated phase and each subcarrier value is divided with a complex estimatedchannel response coefficient (phase tracking phase synchronization andequalization)The equalized signal is demultiplexed into SIGNAL and PSDU partsSIGNAL and PSDU are demapped deinterleaved and decoded A soft viterbidecoding scheme is used in which the received complex symbols are demappedinto soft bit information that is weighted by the channel response coefficientthen fed to a conventional soft binary viterbi decoder Viterbi algorithm finds thepath that maximizes
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Demodulated SIGNAL and PSDU bits are outputThe equalized receiver signal is output for EVM measurementThe deinterleaved PSDU signal is output which is the signal before decoding
The WLAN_80211aRx_Soft receiver schematic is shown in the following figure
WLAN_80211aRx_Soft Schematic
References
IEEE Standard 80211a-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer in the 5 GHzBand 1999MRG Butler S Armour PN Fletcher AR Nix DR Bull Viterbi Decoding2Strategies for 5 GHz Wireless LAN Systems VTC 2001 Fall IEEE VTS 54th
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WLAN_80211aRxFSync
Description Receiver of IEEE 80211a with full frequency synchronizationLibrary WLAN ReceiverClass SDFWLAN_80211aRxFSync
Parameters
Name Description Default Unit Type Range
Length octet number of PSDU 256 int [1 4095]
Rate data rate Mbps_6 Mbps_9 Mbps_12 Mbps_18 Mbps_24Mbps_27 Mbps_36 Mbps_48 Mbps_54
Mbps_6 enum
Order FFT points=2^Order 6 int [6 11]
ScramblerInit initial state of scrambler 1 0 1 1 10 1
intarray
0 1dagger
GuardType type of guard interval T2 T4 T8 T16 T32UserDefined
T4 enum
GuardInterval guard interval defined by user 16 int [0 2Order ]
TSYM one OFDM symbol interval 4e-6 sec real (0 infin)
Idle padded number of zeros between two bursts 0 int [0 infin)
FreqOffset actual frequency offset 00 Hz real (-infin infin)
dagger for each array element array size must be 7
Pin Inputs
Pin Name Description Signal Type
1 input received signal to bedemodulated
complex
Pin Outputs
Pin Name Description Signal Type
2 SIGNAL demodulated SIGNAL signal int
3 DATA demodulated DATA signal int
4 output demodulated signal complex
NotesEquations
This subnetwork implements an IEEE 80211a receiver with full frequency1synchronization Demodulated SIGNAL DATA and data are output The schematicfor this subnetwork is shown in the following figureReceiver functions are implemented according to the IEEE 80211a Standard2
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Start of frame is detected WLAN_BurstSync calculates the correlation betweenthe received signal and the 10 short preambles and selects the index with themaximum correlation value as the start of frame The transition from short tochannel estimation sequences is detected and time (with one sample resolution)is established (burst synchronization)Coarse and fine frequency offsets are estimated WLAN_FreqSync calculates thecoarse frequency offset and makes coarse frequency synchronization using the8th and 9th short preambles WLAN_FineFreqSync calculates the fine frequencyoffset and makes fine frequency synchronization using the two long preamblesThe packet is derotated according to the estimated coarse and fine frequencyoffsets (coarse and fine frequency synchronization) The phase effect caused bythe frequency offset is compensated by WLAN_DemuxBurst WLAN_DemuxBurstoutputs two long preambles and the OFDM symbols for DATA demodulation Thetwo long preamble outputs are used for channel estimationComplex channel response coefficients are estimated for each subcarrier(channel estimation) The phases of the two long preambles are aligned byWLAN_PhaseEst before the channel estimator WLAN_ChEstimator performschannel estimation for 52 subcarriers by combining the two long preambles
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WLAN_80211aRxFSync Schematic
Each data OFDM symbol is transformed into subcarrier received values pilotsubcarrier phases are estimated subcarrier values are derotated according toestimated phase WLAN_PhaseTrack implements these functionsWLAN_MuxDataChEst only duplicates the estimated complex channel responsecoefficients the number of OFDM symbols for DATA and SIGNAL timesEach subcarrier value is divided with a complex estimated channel responsecoefficient (phase tracking phase synchronization and equalization) Thissimple one-tap frequency domain channel response compensation isimplemented by WLAN_OFDMEqualizerAfter equalization WLAN_DemuxOFDMSym demultiplexes 52 subcarriers into 48data and 4 pilot subcarriers The demodulated burst is then demultiplexed intoSIGNAL and PSDU parts in WLAN_DemuxSigData
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SIGNAL and DATA are demapped deinterleaved and decodedDemodulated SIGNAL and PSDU bits are outputThe equalized receiver signal is output for EVM measurementThe deinterleaved PSDU signal is output which is the signal before decoding
References
IEEE Standard 80211a-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer in the 5 GHzBand 1999
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WLAN_80211aRxFSync1
Description Receiver of IEEE 80211a with full frequency synchronizationLibrary WLAN ReceiverClass SDFWLAN_80211aRxFSync1
Parameters
Name Description Default Unit Type Range
Length octet number of PSDU 256 int [1 4095]
Rate data rate Mbps_6 Mbps_9 Mbps_12 Mbps_18 Mbps_24Mbps_27 Mbps_36 Mbps_48 Mbps_54
Mbps_6 enum
Order FFT points=2^Order 6 int [6 11]
ScramblerInit initial state of scrambler 1 0 1 1 10 1
intarray
0 1dagger
GuardType type of guard interval T2 T4 T8 T16 T32UserDefined
T4 enum
GuardInterval guard interval defined by user 16 int [0 2Order ]
TSYM one OFDM symbol interval 4e-6 sec real (0 infin)
Idle padded number of zeros between two bursts 0 int [0 infin)
FreqOffset actual frequency offset 00 Hz real (-infin infin)
dagger for each array element array size must be 7
Pin Inputs
Pin Name Description Signal Type
1 input received signal to bedemodulated
complex
Pin Outputs
Pin Name Description Signal Type
2 For_EVM undemapped signal after FFT used forEVM
complex
3 UnDecodedBits deinterleaved data bits before decoding real
4 PSDU PSDU bits int
5 SIGNAL SIGNAL int
NotesEquations
The model for this subnetwork is based on an IEEE 80211a receiver with full1frequency synchronization The schematic is shown in the following figure
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Receiver functions are implemented according to the IEEE 80211a Standard2Start of frame is detected WLAN_BurstSync calculates the correlation betweenthe received signal and the 10 short preambles and selects the index with themaximum correlation value as the start of frame The transition from short tochannel estimation sequences is detected and time (with one sample resolution)is established (burst synchronization)Coarse and fine frequency offsets are estimated WLAN_FreqSync calculates thecoarse frequency offset and makes coarse frequency synchronization using the8th and 9th short preambles WLAN_FineFreqSync calculates the fine frequencyoffset and makes fine frequency synchronization using the two long preamblesThe packet is derotated according to the estimated coarse and fine frequencyoffsets (coarse and fine frequency synchronization) The phase effect caused bythe frequency offset is compensated by WLAN_DemuxBurst WLAN_DemuxBurstoutputs two long preambles and the OFDM symbols for DATA demodulation Thetwo long preamble outputs are used for channel estimationComplex channel response coefficients are estimated for each subcarrier(channel estimation) The phases of the two long preambles are aligned byWLAN_PhaseEst before the channel estimator WLAN_ChEstimator performschannel estimation for 52 subcarriers by combining the two long preambles
WLAN_80211aRxFSync1 Schematic
Each data OFDM symbol is transformed into subcarrier received values pilot
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subcarrier phases are estimated subcarrier values are derotated according toestimated phase WLAN_PhaseTrack implements these functionsWLAN_MuxDataChEst only duplicates the estimated complex channel responsecoefficients the number of OFDM symbols for DATA and SIGNAL timesEach subcarrier value is divided with a complex estimated channel responsecoefficient (phase tracking phase synchronization and equalization) Thissimple one-tap frequency domain channel response compensation isimplemented by WLAN_OFDMEqualizerAfter equalization WLAN_DemuxOFDMSym demultiplexes 52 subcarriers into 48data and 4 pilot subcarriers The demodulated burst is then demultiplexed intoSIGNAL and PSDU parts in WLAN_DemuxSigDataSIGNAL and DATA are demapped deinterleaved and decodedDemodulated SIGNAL and PSDU bits are output
References
IEEE Standard 80211a-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer in the 5 GHzBand 1999
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WLAN_80211aRxNoFSync
Description Receiver of IEEE 80211a without frequency synchronizationLibrary WLAN ReceiverClass SDFWLAN_80211aRxNoFSync
Parameters
Name Description Default Type Range
Length octet number of PSDU 256 int [1 4095]
Rate data rate Mbps_6 Mbps_9 Mbps_12 Mbps_18 Mbps_24Mbps_27 Mbps_36 Mbps_48 Mbps_54
Mbps_6 enum
Order FFT points=2^Order 6 int [6 11]
ScramblerInit initial state of scrambler 1 0 1 1 10 1
intarray
0 1dagger
GuardType type of guard interval T2 T4 T8 T16 T32 UserDefined T4 enum
GuardInterval guard interval defined by user 16 int [0 2Order ]
Idle padded number of zeros between two bursts 0 int [0 infin)
dagger for each array element array size must be 7
Pin Inputs
Pin Name Description Signal Type
1 input received signal to bedemodulated
complex
Pin Outputs
Pin Name Description Signal Type
2 SIGNAL demodulated SIGNAL signal int
3 DATA demodulated DATA signal int
4 output demodulated signal complex
NotesEquations
This subnetwork model implements a 80211a receiver without frequency1synchronization Demodulated SIGNAL DATA and data are output The schematicfor this subnetwork is shown in the following figure
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WLAN_80211aRxNoFSync Schematic
Receiver functions are implemented according to the IEEE 80211a Standard2Start of frame is detectedTransition from short to channel estimation sequences are detected and time(with one sample resolution) will be established (burst synchronization)Complex channel response coefficients are estimated for each subcarrier(channel estimation)Each data OFDM symbol is transformed into subcarrier received values pilotsubcarrier phases are estimated subcarrier values are derotated according toestimated phase and each subcarrier value is divided with a complex estimatedchannel response coefficient (phase tracking phase synchronization andequalization)The equalized signal is demultiplexed into SIGNAL and DATA partsSIGNAL and DATA are demapped deinterleaved and decoded respectivelyDemodulated SIGNAL and DATA bits are output
References
IEEE Standard 80211a-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer in the 5 GHzBand 1999
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WLAN_80211aRxNoFSync1
Description Receiver of IEEE 80211a without frequency synchronizationLibrary WLAN ReceiverClass SDFWLAN_80211aRxNoFSync1
Parameters
Name Description Default Type Range
Length octet number of PSDU 256 int [1 4095]
Rate data rate Mbps_6 Mbps_9 Mbps_12 Mbps_18 Mbps_24Mbps_27 Mbps_36 Mbps_48 Mbps_54
Mbps_6 enum
Order FFT points=2^Order 6 int [6 11]
ScramblerInit initial state of scrambler 1 0 1 1 10 1
intarray
0 1dagger
GuardType type of guard interval T2 T4 T8 T16 T32 UserDefined T4 enum
GuardInterval guard interval defined by user 16 int [0 2Order ]
Idle padded number of zeros between two bursts 0 int [0 infin)
dagger for each array element array size must be 7
Pin Inputs
Pin Name Description Signal Type
1 input received signal to bedemodulated
complex
Pin Outputs
Pin Name Description Signal Type
2 For_EVM undemapped signal after FFT used forEVM
complex
3 UnDecodedBits deinterleaved data bits before decoding real
4 PSDU PSDU bits int
5 SIGNAL SIGNAL int
NotesEquations
The model for this subnetwork is based on an IEEE 80211a receiver without1frequency synchronization The schematic is shown in the following figure
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WLAN_80211aRxNoFSync1 Subnetwork
Receiver functions are implemented as specified in the IEEE 80211a Standard
Start of frame is detectedThe transition from short to channel estimation sequences is detected and time(with one sample resolution) is established (burst synchronization)The complex channel response coefficients are estimated for each subcarrier(channel estimation)Each data OFDM symbol is transformed into subcarrier received values pilotsubcarrier phases are estimated subcarrier values are derotated according toestimated phase and each subcarrier value is divided with a complex estimatedchannel response coefficient (phase tracking phase synchronization andequalization)The equalized signal is demultiplexed into SIGNAL and PSDU partsSIGNAL and PSDU are demapped deinterleaved and decoded respectivelyDemodulated SIGNAL and PSDU bits are outputThe equalized receiver signal is output for EVM measurementThe deinterleaved PSDU signal is output which is the signal before decoding
References
IEEE Standard 80211a-1999 Part 11 Wireless LAN Medium Access Control (MAC)1
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and Physical Layer (PHY) specifications High-speed Physical Layer in the 5 GHzBand 1999
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WLAN_80211aRx_Soft
Description Receiver of IEEE 80211a with full frequency synchronizationLibrary WLAN ReceiverClass SDFWLAN_80211aRx_Soft
Parameters
Name Description Default Unit Type Range
Length octet number of PSDU 256 int [1 4095]
Rate data rate Mbps_6 Mbps_9 Mbps_12 Mbps_18 Mbps_24Mbps_27 Mbps_36 Mbps_48 Mbps_54
Mbps_6 enum
Order FFT points=2^Order 6 int [6 11]
ScramblerInit initial state of scrambler 1 0 1 1 10 1
intarray
0 1dagger
GuardType type of guard interval T2 T4 T8 T16 T32UserDefined
T4 enum
GuardInterval guard interval defined by user 16 int [0 2Order ]
TSYM one OFDM symbol interval 4e-6 sec real (0 infin)
Idle padded number of zeros between two bursts 0 int [0 infin)
DecoderType demapping type Hard Soft CSI CSI enum
TrunLen path memory truncation length 60 int [20 200]
FreqOffset actual frequency offset 00 Hz real (-infin infin)
dagger for each array element array size must be 7
Pin Inputs
Pin Name Description Signal Type
1 input received signal to bedemodulated
complex
Pin Outputs
Pin Name Description Signal Type
2 For_EVM undemapped signal after FFT used forEVM
complex
3 UnDecodedBits deinterleaved data bits before decoding real
4 PSDU PSDU bits int
5 SIGNAL SIGNAL int
NotesEquations
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This subnetwork implements an IEEE 80211a baseband receiver with soft Viterbi1decoding algorithm The schematic is shown in the following figure
WLAN_80211aRx_Soft Schematic
Receiver functions are implemented as specified in the IEEE 80211a Standard2Start of frame is detected WLAN_BurstSync calculates the correlation betweenthe received signal and the 10 short preambles and selects the index with themaximum correlation value as the start of frame The transition from short tochannel estimation sequences is detected and time (with one sample resolution)is established (burst synchronization)Coarse and fine frequency offsets are estimated WLAN_FreqSync calculates thecoarse frequency offset and makes coarse frequency synchronization using the8th and 9th short preambles WLAN_FineFreqSync calculates the fine frequencyoffset and makes fine frequency synchronization using the two long preamblesThe packet is derotated according to the estimated coarse and fine frequencyoffsets (coarse and fine frequency synchronization) The phase effect caused bythe frequency offset is compensated by WLAN_DemuxBurst WLAN_DemuxBurstoutputs two long preambles and the OFDM symbols for DATA demodulation Thetwo long preamble outputs are used for channel estimationComplex channel response coefficients are estimated for each subcarrier
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(channel estimation) The phases of the two long preambles are aligned byWLAN_PhaseEst before the channel estimator WLAN_ChEstimator performschannel estimation for 52 subcarriers by combining the two long preamblesEach data OFDM symbol is transformed into subcarrier received values pilotsubcarrier phases are estimated subcarrier values are derotated according toestimated phase WLAN_PhaseTrack implements these functionsWLAN_MuxDataChEst only duplicates the estimated complex channel responsecoefficients the number of OFDM symbols for DATA and SIGNAL timesEach subcarrier value is divided with a complex estimated channel responsecoefficient (phase tracking phase synchronization and equalization) Thissimple one-tap frequency domain channel response compensation isimplemented by WLAN_OFDMEqualizerAfter equalization WLAN_DemuxOFDMSym demultiplexes 52 subcarriers into 48data and 4 pilot subcarriers The demodulated burst is then demultiplexed intoSIGNAL and PSDU parts in WLAN_DemuxSigDataThe demodulated SIGNAL and DATA (such as QPSK 16-QAM and 64-QAMmodulation) are demapped by WLAN_SoftDemapper that has three modes
when DecoderType = Hard if b lt 0 -10 is output otherwise 10 is outputwhen DecoderType = Soft if b lt -10 -10 is output if b gt 10 10 isoutputwhen DecoderType = CSI b is multiplied by CSI (= |H(i)|2) and outputEstimated channel impulse responses (H(i)) in WLAN_ChEstimator is theCSI ( channel status information ) here [2]
The demapped SIGNAL and DATA bits are deinterleaved and decodedDemodulated SIGNAL and PSDU bits are outputThe equalized receiver signal (burst) is output for the EVM measurementThe deinterleaved PSDU signal is output which is the signal before decoding
References
IEEE Standard 80211a-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer in the 5 GHzBand 1999MRG Butler S Armour PN Fletcher AR Nix DR Bull Viterbi Decoding2Strategies for 5 GHz Wireless LAN Systems VTC 2001 Fall IEEE VTS 54th
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WLAN_BurstSync
Description Burst synchronizerLibrary WLAN ReceiverClass SDFWLAN_BurstSync
Parameters
Name Description Default Type Range
Length octet number of PSDU 256 int [1 4095]
Rate data rate Mbps_6 Mbps_9 Mbps_12 Mbps_18 Mbps_24Mbps_27 Mbps_36 Mbps_48 Mbps_54
Mbps_6 enum
Order FFT points=2^Order 6 int [6 11]
GuardType type of guard interval T2 T4 T8 T16 T32 UserDefined T4 enum
GuardInterval guard interval defined by user 16 int [0 2Order ]
Idle padded number of zeros between two bursts 0 int [0 infin)
Pin Inputs
Pin Name Description Signal Type
1 input input signals forsynchronization
complex
Pin Outputs
Pin Name Description Signal Type
2 output correlation for OFDM symbol synchronization real
3 index synchronization index int
NotesEquations
This model is used to calculate the correlation of the input signal that is used in1OFDM system timing synchronizationLength and Rate parameters are used to determine the number of complex signals inone burst The number of OFDM symbols N SYM is
N SYM = Ceiling ((16 + 8 times Length +6) N DBPS )
where N DBPS is determined by data rate according to the following table
Rate-Dependent Values
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Data Rate(Mbps)
Modulation CodingRate (R)
Coded Bits perSubcarrier(NBPSC)
Coded Bits perOFDM Symbol(NCBPS)
Data Bits perOFDM Symbol(NDBPS)
6 BPSK 12 1 48 24
9 BPSK 34 1 48 36
12 QPSK 12 2 96 48
18 QPSK 34 2 96 72
24 16-QAM 12 4 192 96
27 16-QAM 916 4 192 108
36 16-QAM 34 4 192 144
48 64-QAM 23 6 288 192
54 64-QAM 34 6 288 216
After determining N SYM the number of input tokens N total can be calculated
N total = (2 Order + 2 Order - 2 _ ) times 4 + (2 _Order + GI ) times ( N SYM + 1) + Idle
where idle is Idle parameter and GI (GuardInterval parameter) is defined as
if GuardType=T32 GI = 2 Order -5
if GuardType=T16 GI = 2 Order -4
if GuardType=T8 GI = 2 Order -3
if GuardType=T4 GI = 2 Order -2
if GuardType=T2 GI = 2 Order -1
if GuardType=UserDefined GI is determined by GuardInterval10 short preambles are used to generate the correlation values for burst2synchronization (2 Order + 2 Order -2 ) times 4 + Idle correlation values are calculatedand the maximum value is selected the index for synchronization corresponds to themaximum correlation value The (2 Order + 2 Order -2 ) times 4 + Idle correlation valuesare output at output pin 2 the synchronization index is output at index pin 3 Themaximum delay range detected by this model is (2 Order + 2 Order -2 ) times 4 + Idle
References
IEEE Standard 80211a-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer in the 5 GHzBand 1999
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WLAN_ChEstimator
Description Channel estimatorLibrary WLAN ReceiverClass SDFWLAN_ChEstimator
Parameters
Name Description Default Type Range
Carriers number of carriers in one OFDM symbol 52 int 52
Order FFT points=2^Order 6 int [6 11]
Pin Inputs
Pin Name Description Signal Type
1 input output signals fromFFT
complex
Pin Outputs
Pin Name Description Signal Type
2 Coef channel coefficient in active subcarriers complex
NotesEquations
The model is used to calculate channel estimation based on the pilot channel and1output the active subcarriers estimated channel impulse response (CIR)This model uses long preambles to estimate the CIRs The estimated CIRs are2calculated using active subcarrier pilot channels The long training symbol include 52subcarriers given by
L 0 51 = 11-1-111-11-1111111-1-111-11-111111-1-111-11-11-1-1-1-1-111-1-11-11-11111
Set x 0 x 1 x 51 are the input signals h 0 h 1 h 51 are the estimated CIRThe estimated CIR can be calculated as follows
where i = 0 1 51
References
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IEEE Standard 80211a-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer in the 5 GHzBand 1999
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WLAN_FineFreqSync
Description Fine carrier frequency synchronizerLibrary WLAN ReceiverClass SDFWLAN_FineFreqSync
Parameters
Name Description Default Unit Type Range
Order FFT points=2^Order 6 int [6 11]
TSYM one OFDM symbol interval 4e-6 sec real (0 infin)
Length octet number of PSDU 256 int (0 4095]
Rate data rate Mbps_6 Mbps_9 Mbps_12 Mbps_18 Mbps_24Mbps_27 Mbps_36 Mbps_48 Mbps_54
Mbps_6 enum
GuardType type of guard interval T2 T4 T8 T16 T32 UserDefined T4 enum
GuardInterval guard interval defined by user 16 int [0 2Order ]
Idle padded number of zeros between two bursts 0 int [0 infin)
Pin Inputs
Pin Name Description Signal Type
1 input input signal for fine frequencysynchronization
complex
2 index synchronization index int
3 CoarseF coarse carrier frequency offset real
Pin Outputs
Pin Name Description Signal Type
4 FineF fine carrier frequency offset real
NotesEquations
This model is used to estimate and output the fine carrier frequency offset between1transmitter and receiver after coarse carrier frequency offset detectionTwo long preambles are used to calculate the fine carrier frequency offset between2transmitter and receiver after coarse carrier frequency offset detection TheWLAN_DemuxBurst model will use the coarse and fine carrier frequency offsetsdetected in WLAN_FreqSync and WLAN_FineFreqSync models to remove carrierfrequency offset in the receiverInput index pin 2 determines the starting point of the two long preambles Thecoarse frequency offset in CoarseF pin3 is used to derotate the preambles Amaximum likelihood algorithm is used to estimate the fine carrier frequency offset
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References
IEEE Standard 80211a-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer in the 5 GHzBand 1999
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WLAN_FreqSync
Description Coarse carrier frequency synchronizerLibrary WLAN ReceiverClass SDFWLAN_FreqSync
Parameters
Name Description Default Unit Type Range
Order FFT points=2^Order 6 int [6 11]
TSYM one OFDM symbol interval 4e-6 sec real (0 infin)
Length octet number of PSDU 256 int (0 4095]
Rate data rate Mbps_6 Mbps_9 Mbps_12 Mbps_18 Mbps_24Mbps_27 Mbps_36 Mbps_48 Mbps_54
Mbps_6 enum
GuardType type of guard interval T2 T4 T8 T16 T32 UserDefined T4 enum
GuardInterval guard interval defined by user 16 int [0 2Order ]
Idle padded number of zeros between two bursts 0 int [0 infin)
Pin Inputs
Pin Name Description Signal Type
1 input input signal for frequency synchronization complex
2 index synchronization index int
Pin Outputs
Pin Name Description Signal Type
3 CoarseF coarse carrier frequencyoffset
real
NotesEquations
This model is used to calculate the carrier frequency offset between the transmitter1and the receiver and output the coarse carrier frequency offsetTwo short preambles ( t 9 and t 10) are used to calculate the carrier frequency2offset WLAN_DemuxBurst will use this coarse carrier frequency offset to remove it inthe receiverInput at index pin 2 is used to determine the starting point of the 10 shortpreambles The maximum likelihood algorithm is used to calculate the offset
References
IEEE Standard 80211a-1999 Part 11 Wireless LAN Medium Access Control (MAC)1
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and Physical Layer (PHY) specifications High-speed Physical Layer in the 5 GHzBand 1999
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WLAN_OFDMEqualizer
Description OFDM equalizer by the channel estimationLibrary WLAN ReceiverClass SDFWLAN_OFDMEqualizer
Parameters
Name Description Default Type Range
Carriers number of active carriers in one OFDMsymbol
52 int (0 infin)
Pin Inputs
Pin Name Description Signal Type
1 input data in the active carriers in OFDM symbol complex
2 Coef frequency channel impulse response(CIR) estimation complex
Pin Outputs
Pin Name Description Signal Type
3 output output data after channel equalization complex
NotesEquations
This model is used to perform channel equalization using the channel estimation in1each active carrierThe OFDM channel equalization algorithm is2
where h ( i ) is the channel estimation x ( i ) is the received signal in active carriers a( i ) is the equalized output signal
References
IEEE Standard 80211a-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer in the 5 GHzBand 1999
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WLAN_PhaseEst
Description Phase estimatorLibrary WLAN ReceiverClass SDFWLAN_PhaseEst
Parameters
Name Description Default Type Range
Carriers number of carriers in one OFDM symbol 52 int 52
Order FFT points=2^Order 6 int [6 11]
Pin Inputs
Pin Name Description Signal Type
1 LPrmbl1 first long preamble signals from FFT complex
2 LPrmbl2 second long preamble signals fromFFT
complex
Pin Outputs
Pin Name Description Signal Type
3 output channel coefficient in active subcarriers complex
4 theta phase difference between two longpreambles
real
NotesEquations
This model is used to estimate the phase difference between the two long input1preamblesAccording to IEEE 80211a standard there are two long preambles in every burst2which is used for channel estimation The maximum likelihood algorithm is used tocalculate the phase offset between the two long preambles The detected phaseoffset is used to correct the second long preamble so that both long preambles havethe same phase A combined long preamble is then output and used in theWLAN_ChEstimator modelThe detected phase offset is output at theta pin 4
References
IEEE Standard 80211a-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer in the 5 GHzBand 1999
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WLAN_PhaseTrack
Description Phase tracker in OFDM de-modulationLibrary WLAN ReceiverClass SDFWLAN_PhaseTrack
Parameters
Name Description Default Type Range
Length octet number of PSDU 100 int [14095]
Rate data rate Mbps_6 Mbps_9 Mbps_12 Mbps_18 Mbps_24 Mbps_27Mbps_36 Mbps_48 Mbps_54
Mbps_6 enum
Carriers number of carriers in one OFDM symbol 52 int 52
Order FFT points=2^Order 6 int [6 11]
Phase initial phase of pilots 0 int [0 126]
Pin Inputs
Pin Name Description Signal Type
1 input all sub-carriers in one OFDM symbol complex
2 chl estimated channel impulse response complex
Pin Outputs
Pin Name Description Signal Type
3 output active sub-carriers after removing null sub-carriers complex
4 Coef channel coefficient in active subcarriers complex
5 theta phase difference between current CIR and estimated CIR real
NotesEquations
The model is used to track the phase caused by doppler shift in OFDM demodulation1systems remove the null carrier in one OFDM symbol and update the estimated CIRusing the phase offset detected in the phase tracking algorithmAccording to IEEE 80211a standard the positions from 27 to 37 and the 0 position2are set to zero These 12 subcarriers are set to zero in the WLAN_LoadIFFTBuffmodel In the receiver these 12 zero subcarriers will be removed which is the inverseprocedure of WLAN_LoadIFFTBuffSignals from chl pin 2 are output directly at Coef pin 4 The 12 zero subcarrier signalswill be removed from 64 point signals and form 52 active subcarriers signals that areoutput at output pin 3Assume
x (0) x (1) x (2 Order -1) are input signalsy (0) y (1) y (51) are output signals
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Then
y ( i ) = x (2 Order - 26 + i ) i = 0 1 25y ( i +26) = x ( i + 1) i = 0 1 25
At the same time this model uses the four pilots to obtain the estimated CIR of thefour subcarriers The maximum likelihood algorithm is used to detect the phase offsetθ between input chl pin 2 and the current estimated CIR The phase offset θ is outputat theta pin 5 The estimated CIRs from input chl pin 2 are updated by phase offset θSet h 0 h 1 h 51 and hprime 0 hprime1 hprime51 are the input estimated and updated
CIRs respectively
The updated CIRs hprime 0 hprime1 hprime51 are output at Coef pin 4
References
IEEE Standard 80211a-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer in the 5 GHzBand 1999
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WLAN_RmvNullCarrier
Description Null sub-carriers remover in OFDMLibrary WLAN ReceiverClass SDFWLAN_RmvNullCarrier
Parameters
Name Description Default Type Range
Carriers number of carriers in one OFDM symbol 52 int 52
Order FFT points=2^Order 6 int [6 11]
Pin Inputs
Pin Name Description Signal Type
1 input all sub-carriers in one OFDM symbol complex
2 chl estimated channel impulse response complex
Pin Outputs
Pin Name Description Signal Type
3 output active sub-carriers after removing null sub-carriers
complex
4 Coef channel coefficient in active subcarriers complex
NotesEquations
This model is used to remove the null carrier in one OFDM symbol (It does not have1the phase tracking functionality of the WLAN_PhaseTrack model)According to IEEE 80211a standard the 27 to 37 and the 0 positions are set to zero2these 12 subcarriers are set to zero in the WLAN_LoadIFFTBuff model In thereceiver these zero subcarriers will be removed (the inverse procedure ofWLAN_LoadIFFTBuff)Input chl pin 2 signals are output directly at Coef pin 4 12 zero subcarrier signals willbe removed from the 64 point signals to form 52 active subcarriers signals output atoutput pin 3Assume
x (0) x (1) x (2 Order -1) are input signalsy (0) y (1) y (51) are output signals
Then
y ( i ) = x (2 Order - 26 + i ) i = 0 1 25y ( i +26) = x ( i + 1) i = 0 1 25
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References
IEEE Standard 80211a-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer in the 5 GHzBand 1999
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11b ReceiversWLAN 11bBurstRec (wlan)WLAN 11bBurstSync (wlan)WLAN 11bCIREstimator (wlan)WLAN 11bDemuxBurst (wlan)WLAN 11bDescrambler (wlan)WLAN 11bDFE (wlan)WLAN 11b Equalizer (wlan)WLAN 11bFreqEstimator (wlan)WLAN 11bPreamble (wlan)WLAN 11bRake (wlan)WLAN 11b Rake (wlan)WLAN CCKDemod (wlan)WLAN CCK RF Rx DFE (wlan)WLAN CCK RF Rx Rake (wlan)WLAN CCK Rx DFE (wlan)WLAN CCK Rx Rake (wlan)WLAN Despreader (wlan)WLAN FcCompensator (wlan)WLAN HeaderDemap (wlan)WLAN PhaseRotator (wlan)WLAN PrmblDemap (wlan)WLAN RecFilter (wlan)
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WLAN_11bBurstRec
Description 11b burst receiverLibrary WLAN 11b ReceiverClass SDFWLAN_11bBurstRec
Parameters
Name Description Default Unit Type Range
Rate data rate Mbps_1 Mbps_2 Mbps_55 Mbps_11 Mbps_55 enum
ModType modulation type CCK PBCC CCK enum
PLCPType PLCP preamble type Long Short Long enum
Octets octet number of PSDU 100 int (0 2312]
RampTime power on and off ramp time 20microsec sec real [0microsec 1000microsec]
PwrType power on and off ramp type None LinearCosine
None enum
SampsPerChip number of samples per chip 2 int [2 8]
IdleInterval idle time 500microsec sec real [10microsec1000microsec]
Pin Inputs
Pin Name Description Signal Type
1 BurstIn input burstdata
complex
Pin Outputs
Pin Name Description Signal Type
2 BurstOut output burst data complex
3 SyncOut output signal for 11b burst and frequencysynchronization
complex
NotesEquations
This model is used to output signals for 80211b burst (or timing) synchronization1and carrier frequency synchronization which includes the PreambleRate ModType PLCPType Octets RampTime PwrType SampsPerChip and2IdleInterval parameters are used to specify the number of complex signals in oneburstThe following figure illustrates the format for the interoperable (long) PPDU includingthe High Rate PLCP preamble the High Rate PLCP header and the PSDU
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Long PLCP PPDU Format
The following figure illustrates the format of the PPDU with HRDSSSshort
Short PLCP PPDU Format
In the WLAN Design Library one 80211b burst consists of Idle Ramp (Transmitpower-on and power-down ramp) PLCP Preamble (Long or Short) PLCP Header(Long or Short) and PSDUThe length of PLCP Preamble (mPLCP) is determined by the PLCPType parameter
The length of Header (mHeader) is determined by the PLCPType parameter
The length of PSDU (mPSDU) is determined by the Rate parameter
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The length of Ramp (mRamp) can be calculated as follows
The length of Idle (mIdle) can be calculated as follows
So the total number of one 80211b burst is
All input data (BurstIn pin) is output at pin 2 (BurstOut pin)Pin 3 (SyncOut) outputs the 11b burst and frequency synchronization signal whichincludes the PLCP Preamble In the WLAN Design Library Idle is added before andafter the actual 80211b burst the transmit power-on ramp is also added before theactual 80211b So the half Idle and transmit power-on ramp model must bediscarded in order to output the PLCP Preamble for burst and frequencysynchronization SyncOut outputs mPLCP+3 times 11 times SampsPerChip samples frommIdle2+mRamp2 point in the input burst (BurstIn input pin)This model is used before WLAN_11bBurstSync and WLAN_FreqEstimator in an80211b receiver
References
IEEE Standard 80211b-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer Extension in the24 GHz Band 1999IEEE Standard 80211-1999 Part 11 Wireless LAN Medium Access Control (MAC)2and Physical Layer (PHY) specifications 1999
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WLAN_11bBurstSync
Description 11b burst synchronizerLibrary WLAN 11b ReceiverClass SDFWLAN_11bBurstSyncDerived From WLAN_11bBase
Parameters
Name Description Default Unit Type Range
MaxSearchDelay time range for searching fading path 30microsec sec real [3microsec 10microsec]
SyncEstWindow number of preamble symbols used for burstsynchronization
20 int [1 128] ifPLCPType=Long[1 56] ifPLCPType=Short
SampsPerChip number of samples per chip 2 int [2 8]
PLCPType PLCP preamble type Long Short Long enum
Pin Inputs
Pin Name Description Signal Type
1 Ref reference signal for synchronization int
2 SyncIn input signals for synchronization complex
Pin Outputs
Pin Name Description Signal Type
3 index finger index int
4 max_index synchronization index int
5 corr correlation forsynchronization
real
NotesEquations
This model is used to implement the burst synchronization for 80211b1The correlation values between the received and the reference signals are calculated2for synchronization The number of preamble symbols used for the correlationcalculation is set by SyncEstWindow and the search range is set by MaxSearchDelayThe maximum correlation value is searched for and the corresponding index isselected as the burst start point The index corresponding to the maximumcorrelation value is output at pin max_indexAll correlation values are output at pin corr After output all correlation values are3rearranged from maximum to minimum The corresponding indexes are alsorearranged and output at pin index for the multi-path search
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References
IEEE Standard 80211b-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer Extension in the24 GHz Band 1999IEEE Standard 80211-1999 Part 11 Wireless LAN Medium Access Control (MAC)2and Physical Layer (PHY) specifications 1999
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WLAN_11bCIREstimator
Description 11b channel estimatorLibrary WLAN 11b ReceiverClass SDFWLAN_11bCIREstimatorDerived From WLAN_11bBase
Parameters
Name Description Default Unit Type Range
MaxSearchDelay time range for searching fading path 30usec sec real [3usec 10usec]
FingerNumber number of rake receiver fingers 3 int [1 30]
CIREstWindow number of preamble symbols used toestimate channel
20 int [1 128] ifPLCPType=Long[1 56] ifPLCPType=Short
SampsPerChip number of samples per chip 2 int [2 8]
PLCPType PLCP preamble type Long Short Long enum
Pin Inputs
Pin Name Description Signal Type
1 Index samples index of channel delay int
2 Ref preamble symbols used to estimate channel complex
3 PLCP 11b received PLCP signal suffered from channel distortion complex
Pin Outputs
Pin Name Description Signal Type
4 FingerIdx samples index of channeldelay
int
5 CIR channel CIR complex
NotesEquations
This model is used to estimate the fading channel impulse response1Each firing the position of each resolved channel is input from pin Index thepreambles affected by the fading channels are received by pin PLCP and the primepreamble bits are received by pin Ref The channels are then estimated and output atpin CIREach firing PLCP Index and Ref pins consume tokens separately as follows
(MaxSearchDelay times 11E6+PLCPLength times 11) times SampsPerChip(MaxSearchDelay times 11E6) times SampsPerChipPLCPLength is 144 if PCLPType is set to Long otherwise 72At the same time FingerNumber tokens are produced from pin CIR andFingerIdx
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MaxSearchDelay specifies the range for searching fading channels the value must be2set larger than the sum of system delay and maximum multipath delayFingerNumber specifies the number of estimated channels output at pin CIR3CIREstWindow specifies the number of preamble symbols used to estimate the CIR of4channels
References
IEEE Standard 80211b-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer Extension in the24 GHz Band 1999
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WLAN_11bDemuxBurst
Description 11b burst demultiplexer and frequency compensatorLibrary WLAN 11b ReceiverClass SDFWLAN_11bDemuxBurst
Parameters
Name Description Default Unit Type Range
Rate data rate Mbps_1 Mbps_2 Mbps_55 Mbps_11 Mbps_55 enum
ModType modulation type CCK PBCC CCK enum
PLCPType PLCP preamble type Long Short Long enum
Octets octet number of PSDU 100 int (0 2312]
RampTime power on and off ramp time 20microsec sec real [0microsec 1000microsec]
PwrType power on and off ramp type None LinearCosine
None enum
SampsPerChip number of samples per chip 2 int [2 8]
IdleInterval idle time 500microsec sec real [10microsec1000microsec]
FreqOffset actual frequency offset 00 Hz real (-infin infin)
Pin Inputs
Pin Name Description Signal Type
1 BurstIn input burst data complex
2 Index burst synchronization index int
3 DeltaF estimated frequency offset real
Pin Outputs
Pin Name Description Signal Type
4 BurstOut output burst data complex
NotesEquations
This model implements compensation for carrier frequency offset Each firing the1frequency offset detected by WLAN_11bFreqEstimator is input to pin DeltaF and theburst with frequency offset is input to BurstIn The burst is then compensated bymultiplying exp(-j times 2 times PI times DeltaF times n) where n is the number of burst samplesfrom 1 to entire burst length and is output to pin BurstOutRate ModType PLCPType Octets RampTime PwrType SampsPerChip and2IdleInterval parameters are used to specify the number of complex signals in oneburst In the WLAN Design Library one 80211b burst consists of Idle Ramp(transmit power-on and power-down ramp) PLCP Preamble (Long or Short) PLCPHeader (Long or Short) and PSDU
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The length of PLCP Preamble (mPLCP) is determined by PLCPType parameter
The length of Header (mHeader) is determined by PLCPType parameter
The length of PSDU (mPSDU) is determined by Rate parameter
The length of Ramp (mRamp) can be calculated as follows
The length of Idle (mIdle) can be calculated as follows
So the total of one 80211b burst (at BurstIn) is
The actual burst includes PLCP Preamble PLCP Header and a 3-part PSDU SoWLAN_11bDemuxBurst outputs the actual number of 80211b bursts (mActual) whichis calculated as follows
The transmitter transmits burst-by burst in ADS The burst sequence is a continuous3stream (The 80211 burst is transmitted burst-by-burst) This model includes afrequency compensator The transmitted consecutive bursts are independentThe estimated frequency offset (Δ f i ) of each received burst is input at DeltaF To
avoid estimated frequency offset impacting the next bursts in the frequencycompensator the FreqOffset parameter in this model is set as the actual frequencyoffset between the transmitter and the receiver When the ith burst is processed theactual phase of previous i-1 bursts is calculated and removed by FreqOffset The ithestimated frequency offset (Δ f i ) is used to compensate for the phase in current
burst onlyAssume x 0 x 1 x Total -1 sequences are the BurstIn burst signals after removing
the actual phase of previous i -1 bursts caused by the frequency offset from
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FreqOffset The y 0 y 1 y Total -1 sequences (whose phase caused by frequency
offset) are removed
where
Δ f i is frequency offset of ith received burst which is the input in DeltaF
is the sample time interval in 80211bsystem
After frequency offset compensation the actual 80211b burst is output Index pin 2inputs the start of a detected 80211b burst (including ramps and idle) fromWLAN_11bBurstSync The ramps and idle must be discarded when the actual burst isoutput the equation is
sequences are output
References
IEEE Standard 80211b-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer Extension in the24 GHz Band 1999IEEE Standard 80211-1999 Part 11 Wireless LAN Medium Access Control (MAC)2and Physical Layer (PHY) specifications 1999
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WLAN_11bDescrambler
Description 11b descramblerLibrary WLAN 11b ReceiverClass SDFWLAN_11bDescrambler
Parameters
Name Description Default Type Range
InitState initial state of scrambler 1 1 0 1 1 0 0 intarray
0 or 1array size is 7
Octets number of octets inPSDU
100 int (0 2336]
Pin Inputs
Pin Name Description Signal Type
1 input bits to bedescrambled
int
Pin Outputs
Pin Name Description Signal Type
2 output descrambledbits
int
NotesEquations
This component descrambles all input data bits Each firing when Octets bytes are1consumed and produced the descrambler is reset to its initial stateThe generator polynomial of the scrambler is G ( z ) = z -7 + z -4 + 1 the2corresponding descrambler is illustrated in the following figure
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Data Desrambler
The feed-through configuration of the scrambler and descrambler is self-synchronizing which requires no prior knowledge of the transmitter initialization ofthe scrambler for receiver processing
References
IEEE Standard 80211b-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer Extension in the24 GHz Band 1999
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WLAN_11bDFE
Description decision feedback equalizer for 11bLibrary WLAN 11b ReceiverClass SDFWLAN_11bDFE
Parameters
Name Description Default Type Range
Rate data rate Mbps_1 Mbps_2 Mbps_55Mbps_11
Mbps_55 enum
ModType modulation type CCK PBCC CCK enum
PLCPType PLCP preamble type Long Short Long enum
Octets octet number of PSDU 100 int (0 2312]
Algorithm algorithm for equalizer RLS LMS RLS enum
FwdTaps number of forward taps in equalizer 5 int [1 256]
FbkTaps number of feedback taps in equalizer 3 int [1 128]
Alpha scale factor for LMS algorithm 00004 real (00 10)
Lambda weighting factor for RLS algorithm 0999 real (00 10)
Delta small positive constant for RLS algorithm 0001 real (00100]
Pin Inputs
Pin Name Description Signal Type
1 BurstIn input signal before equalizer complex
2 PrmblIn input training preamble forequalizer
complex
Pin Outputs
Pin Name Description Signal Type
3 BurstOut output data after equalizer complex
NotesEquations
This model implements decision feedback equalization for input 80211b burst1Rate ModType PLCPType and Octets parameters are used to specify the number of2complex signals in one burst In the WLAN Design Library one real 80211b burstconsists of PLCP Preamble (Long or Short) PLCP Header (Long or Short) and PSDUThe length of PLCP Preamble (mPLCP) is determined by the PLCPType parameter
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The length of Header (mHeader) is determined by the PLCPType parameter
The length of PSDU (mPSDU) is determined by Rate parameter
So the total of one 80211b burst is
Each firing Total tokens are input at BurstIn and Total tokens are output atBurstOutPin 1 (BurstIn) input3
sequences to be equalized Pin 2 (PrmblIn) input mPLCP training sequences
which is used to train the decision feedback equalizer Pin 3 (BurstOut) outputequalized sequence
Pin 2 (PrmblIn) must be connected with pin 3 (PrmblChip) of WLAN_11bPreambleThis model implements a decision feedback equalizer The equalizer works in training4and tracking modesIn the training mode the training sequence (from pin2 PrmblIn) is used as trainingsequence The number of training sequences is mPLCP The error signal e k (see note
5) is from the training signal After the training mode the decision feedbackequalizer coefficient is converged and the equalizer enters into the tracking modeThe error signal e k is from the decision signal of the equalized signal
This model supports the LMS and RLS algorithms to equalize the input signal Users5can select one algorithm to equalize the received signal according to various testcases The following figure illustrates the decision feedback equalizer
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Decision Feedback Equalizer
LMS AlgorithmThe criterion most commonly used in the optimization of the equalizer coefficients isthe minimization of the mean square error (MSE) between the desired equalizeroutput and the actual equalizer outputMSE minimization can be accomplished recursively by use of the stochastic gradientalgorithm introduced by Widrow called the LMS algorithm This algorithm isdescribed by the coefficient update equation
where
C k is the vector of the equalizer coefficients at the kth iteration
X k represents the signal vector
Recursive Least-Squares (Kalman) AlgorithmThe convergence rate of the LMS algorithm is slow because a single parameter αcontrols the rate of adaptation A fast converging algorithm is obtained if a recursiveleast squares (RLS) criterion for adjustment of the equalizer coefficientsThe RLS iteration algorithm followsCalculate output
Calculate error
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Calculate Kalman gain vector
Update inverse of the correlation matrix
Update coefficients
References
IEEE Standard 80211b-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer Extension in the24 GHz Band 1999IEEE Standard 80211-1999 Part 11 Wireless LAN Medium Access Control (MAC)2and Physical Layer (PHY) specifications 1999John G Proakis Digital Communications Third Edition page 636-679 McGraw-Hill31995John G Proakis Adaptive Equalization for TDMA Digital Mobile Radio IEEE Trans on4Vehicular Technology page 333-341 Vol 40 No2 May 1991
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WLAN_11b_Equalizer
Description 11b receiver with equalizerLibrary WLAN 11b ReceiverClass SDFWLAN_11b_Equalizer
Parameters
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Name Description Default Unit Type Range
Rate data rate Mbps_1 Mbps_2 Mbps_55Mbps_11
Mbps_55 enum
ModType modulation type CCK PBCC CCK enum
PLCPType PLCP preamble type Long Short Long enum
Octets octet number of PSDU 100 int (0 2312]
InitPhase initial phase of DBPSK 0785 real [0 2π )
ScramblerInit initial state of scrambler 1 1 0 1 1 00
intarray
0 1dagger
PwrType power on and off ramp type NoneLinear Cosine
None enum
RampTime power on and off ramp time 20microsec sec real [0microsec 1000microsec]
SampsPerChip number of samples per chip 2 int [2 8]
IdleInterval idle time 500microsec sec real [0microsec 1000microsec]
FilterType pulse-shaping filter type RectangleGaussian Root-Cosine Off
Off enum
Taps number of taps 6 int [1 1000]
Alpha roll-off factor for root raised-cosine filter 05 real (0 10]
BT product of 3dB bandwidth and symboltime for Gaussian filter
05 real (0 10]
MaxSearchDelay time range for searching fading path 30microsec sec real [3microsec 10microsec]
FingerNumber number of rake receiver fingers 3 int [1 30]
FreqEstWindow number of preamble symbols used toestimate frequency offset
20 int [1 128] ifPLCPType=Long[1 56] ifPLCPType=Short
SyncEstWindow number of preamble symbols used forburst synchronization
20 int [1 128] ifPLCPType=Long[1 56] ifPLCPType=Short
EquAlgorithm algorithm for equalizer RLS LMS RLS enum
FwdTaps number of forward taps in equalizer 5 int [1 256]
FbkTaps number of feedback taps in equalizer 3 int [1 128]
EquAlpha scale factor for LMS algorithm 00004 real (00 10)
Lambda weighting factor for RLS algorithm 0999 real (00 10)
Delta small positive constant for RLS algorithm 0001 real (00 100]
DownSamplePhase phase of down sample model with rangefrom 0 to SampsPerChip-1
0 int [00 SampsPerChip-1]
FreqOffset actual frequency offset 00 Hz real (-infin infin)
dagger for each array element array size must be 7
Pin Inputs
Pin Name Description Signal Type
1 BurstIn received burst complex
Pin Outputs
Pin Name Description Signal Type
2 AfterEqu 11b burst after equalizer complex
3 BeforeEqu 11b burst beforeequalizer
complex
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NotesEquations
This subnetwork implements an 80211b receiver with decision feedback equalizer It1performs burst synchronization carrier frequency synchronization and decisionfeedback equalization The schematic for this subnetwork is shown in the followingfigure
WLAN_11b_Equalizer Schematic
This subnetwork outputs both the full PPDU frame before and after the equalizer So2the constellation can be shown before or after the decision feedback equalizer ThePPDU frames are illustrated in the following figures one PPDU frame includes PLCPPreamble PLCP Header and PSDU
Long PLCP PPDU Format
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Short PLCP PPDU Format
References
IEEE Standard 80211b-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer Extension in the24 GHz Band 1999IEEE Standard 80211-1999 Part 11 Wireless LAN Medium Access Control (MAC)2and Physical Layer (PHY) specifications 1999John G Proakis Digital Communications Third Edition page 636-679 McGraw-Hill31995John G Proakis Adaptive Equalization for TDMA Digital Mobile Radio IEEE Trans on4Vehicular Technology page 333-341 Vol 40 No2 May 1991
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WLAN_11bFreqEstimator
Description 11b frequency offset estimatorLibrary WLAN 11b ReceiverClass SDFWLAN_11bFreqEstimatorDerived From WLAN_11bBase
Parameters
Name Description Default Unit Type Range
MaxSearchDelay time range for searching fading path 30microsec sec real [3microsec 10microsec]
FingerNumber number of rake receiver fingers 3 int [1 30]
FreqEstWindow number of preamble symbols used to estimatefrequency offset
20 int [1 128] ifPLCPType=Long[1 56] ifPLCPType=Short
SampsPerChip number of samples per chip 2 int [2 8]
PLCPType PLCP preamble type Long Short Long enum
Pin Inputs
Pin Name Description Signal Type
1 SyncIn input signal for frequency synchronization complex
2 Ref reference signal for frequency estimation complex
3 index synchronization index int
Pin Outputs
Pin Name Description Signal Type
4 DeltaF coarse carrier frequencyoffset
real
NotesEquations
This model is used to estimate the carrier frequency offset between the transmitter1and the receiver for 80211bBefore frequency offset estimation channel estimation is completed and the received2signals are rake combined in this model to ensure the excellent SNR The fingernumber for rake combination is set by FingerNumberThe maximum likelihood principle is applied to the frequency offset estimation The3received signals are differentiated and denoted as Y [ k ] and the reference signal isdenoted as d[k] the estimate of frequency offset is as follows
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3
where
T denotes the time duration of one symbolN denotes the number of symbols used for frequency offset estimation andset by the FreqEstWindow parameter
The result is output at DeltaF
References
IEEE Standard 80211b-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer Extension in the24 GHz Band 1999IEEE Standard 80211-1999 Part 11 Wireless LAN Medium Access Control (MAC)2and Physical Layer (PHY) specifications 1999
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WLAN_11bPreamble
Description Signal source of 11b preambleLibrary WLAN 11b ReceiverClass SDFWLAN_11bPreamble
Parameters
Name Description Default Type Range
PLCPType PLCP preamble type Long Short Long enum [0 1]
InitPhase initial phase of DBPSK PI 4 real [0 2π )
ScramblerInit initial state of scrambler 1 1 0 1 1 0 0 int array 0 1dagger
dagger for each array element array size must be 7
Pin Outputs
Pin Name Description Signal Type
1 PrmblBits 80211b preamble bits after scrambler int
2 PrmblSym 80211b preamble after DBPSKmodulation
complex
3 PrmblChip 80211b preamble after Barker spreader complex
NotesEquations
This subnetwork outputs the PLCP preamble bits mapping signals and chip signals1The schematic for this subnetwork is shown in the following figure
WLAN_11bPreamble Schematic
Both long and short PLCP preambles use 1 Mbits DBPSK modulation2
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The InitPhase parameter specifies the initial phase of the DBPSK signal DBPSKencoding is given in the following table
DBPSK Encoding
Bit Input Phase Change (+jw)
0 0
1 π
The 11-chip Barker sequence is used as the PN code sequence for the 1 and 2 Mbits3modulation
+1 -1 +1 +1 -1 +1 +1 +1 -1 -1 -1
The left-most chip is output first in time The first chip is aligned at the start of atransmitted symbol The symbol duration will be exactly 11 chips long
References
IEEE Standard 80211b-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer Extension in the24 GHz Band 1999IEEE Standard 80211-1999 Part 11 Wireless LAN Medium Access Control (MAC)2and Physical Layer (PHY) specifications 1999
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WLAN_11bRake
Description 11b rake combinerLibrary WLAN 11b ReceiverClass SDFWLAN_11bRakeDerived From WLAN_11bBase
Parameters
Name Description Default Unit Type Range
FingerNumber number of rake receiver fingers 3 int [1 30]
SampsPerChip number of samples per chip 2 int [2 8]
Rate data rate Mbps_1 Mbps_2 Mbps_55 Mbps_11 Mbps_55 enum
PLCPType PLCP preamble type Long Short Long enum
Octets octet number of PSDU 100 int (0 2312]
PwrType power on and off ramp type None LinearCosine
None enum
RampTime power on and off ramp time 20microsec sec real [0microsec 1000microsec]
ModType modulation type CCK PBCC CCK enum
IdleInterval idle time 500microsec sec real [10microsec1000microsec]
Pin Inputs
Pin Name Description Signal Type
1 Index samples index of channeldelay
int
2 CIR channel CIR complex
3 BurstIn 11b received signal complex
Pin Outputs
Pin Name Description Signal Type
4 BurstOut 11b multipath combinedsignal
complex
NotesEquations
This model implements coherent receiving with maximal ratio combining (MRC) The1necessary coefficients for rake combining including multipath delay and channelimpulse response are received from the channel estimator componentEach firing the position of each finger is input from pin Index the CIR are receivedby pin CIR at the same time the burst whose frequency deviation has beencompensated are received by pin BurstIn Then MRC are implementedEach firing the pin BurstIn CIR and Index consume tokens separately as follows(RampTime times 2+IdleInterval) times 11E6 times SampsPerChip+DataLength
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DataLength can be calculated asDataLength = (NPLCP+NSYM) times SampsPerChipif PLCPType=Long (NPLCP=(144+48) times 11) else (NPLCP=(72+24) times 11)
if Rate=1 Mbps (NSYM=Octets times 8 times 11)if Rate=2 Mbps (NSYM=Octets times 4 times 11)if Rate=55 Mbps(NSYM=Octets times 8 times 2)if Rate=11 Mbps ((NSYM=Octets times 8)
At the same time DataLength tokens are produced from pin BurstOutFingerNumber specifies the number of combined paths2
References
IEEE Standard 80211b-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer Extension in the24 GHz Band 1999IEEE Standard 80211-1999 Part 11 Wireless LAN Medium Access Control (MAC)2and Physical Layer (PHY) specifications 1999
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WLAN_11b_Rake
Description 11b rake receiverLibrary WLAN 11b ReceiverClass SDFWLAN_11b_Rake
Parameters
Name Description Default Unit Type Range
Rate data rate Mbps_1 Mbps_2 Mbps_55Mbps_11
Mbps_55 enum
ModType modulation type CCK PBCC CCK enum
PLCPType PLCP preamble type Long Short Long enum
Octets octet number of PSDU 100 int (0 2312]
InitPhase initial phase of DBPSK 0785 real [0 2π )
ScramblerInit initial state of scrambler 1 1 0 1 1 00
intarray
0 1dagger
PwrType power on and off ramp type None LinearCosine
None enum
RampTime power on and off ramp time 20microsec sec real [0microsec 1000microsec]
SampsPerChip number of samples per chip 2 int [2 8]
IdleInterval idle time 500microsec sec real [10microsec 1000microsec]
FilterType pulse-shaping filter type RectangleGaussian Root-Cosine Off
Off enum
Taps number of taps 6 int [1 1000]
Alpha roll-off factor for root raised-cosine filter 05 real (0 10]
BT product of 3dB bandwidth and symbol timefor Gaussian filter
05 real (0 10]
MaxSearchDelay time range for searching fading path 30microsec sec real [3microsec 10microsec]
FingerNumber number of rake receiver fingers 3 int [1 30]
CIREstWindow number of preamble symbols used toestimate channel
20 int [1 128] ifPLCPType=Long[1 56] ifPLCPType=Short
FreqEstWindow number of preamble symbols used toestimate frequency offset
20 int [1 128] ifPLCPType=Long[1 56] ifPLCPType=Short
SyncEstWindow number of preamble symbols used forburst synchronization
20 int [1 128] ifPLCPType=Long[1 56] ifPLCPType=Short
FreqOffset actual frequency offset 00 Hz real (-infin infin)
dagger for each array element array size must be 7
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Pin Inputs
Pin Name Description Signal Type
1 BurstIn received burst complex
Pin Outputs
Pin Name Description Signal Type
2 AfterRake 11b burst after rake receiver complex
NotesEquations
This subnetwork implements IEEE 80211b rake receiver It performs burst1synchronization carrier frequency synchronization channel estimation and rakecombination The schematic for this subnetwork is shown in the following figure
WLAN_11b_Rake Schematic
This subnetwork outputs the full PPDU frame after rake combination The PPDU2frames are illustrated in the following figures one PPDU frame includes PLCPPreamble PLCP Header and PSDU
Long PLCP PPDU Format
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Short PLCP PPDU Format
References
IEEE Standard 80211b-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer Extension in the24 GHz Band 1999IEEE Standard 80211-1999 Part 11 Wireless LAN Medium Access Control (MAC)2and Physical Layer (PHY) specifications 1999John G Proakis Digital Communications Third Edition page 636-679 McGraw-Hill31995
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WLAN_CCKDemod
Description 11b CCK demodulatorLibrary WLAN 11b ReceiverClass SDFWLAN_CCKDemod
Parameters
Name Description Default Type Range
Rate data rate Mbps_55 Mbps_11 Mbps_55 enum
Octets octet number of PSDU 100 int (0 2312]
Pin Inputs
Pin Name Description Signal Type
1 CCKIn input signal for CCK demodulator complex
2 InitialPhase initial phase complex
Pin Outputs
Pin Name Description Signal Type
3 PSDU signal demodulated toPSDU
complex
NotesEquations
This model implements 11b CCK demodulator Each firing the NSYM tokens are1consumed by pin CCKIn and Octets times 8 tokens are produced by pin PSDUNSYM can be calculated as follows
if Rate=55 Mbps(NSYM=Octets times 8 times 2)if Rate=11 Mbps((NSYM=Octets times 8)
The CCK demodulation is implemented with a correlator to correlate the 4 or 64 CCK2complex code word The correlator is followed by a biggest picker which finds thebiggest of 4 or 64 correlator outputs depending on the rate where 4 if rate is 55Mand 64 if rate is 11M This is translated into two or six data bits The detected outputis then processed through the differential phase decoder to demodulate the last twobits of the symbol
References
IEEE Standard 80211b-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer Extension in the24 GHz Band 1999
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WLAN_CCK_RF_Rx_DFE
Description 80211b CCK receiver with equalizerLibrary WLAN 11b ReceiverClass TSDFWLAN_CCK_RF_Rx_DFE
Parameters
Name Description Default Unit Type Range
RIn input resistance DefaultRIn Ohm real (0 infin)
ROut output resistance DefaultROut Ohm real (0 infin)
RTemp physical temperature indegrees C
DefaultRTemp Ohm real [-27315 infin]
RefFreq internal reference frequency 2400MHz Hz real (0 infin)
Sensitivity voltage output sensitivityVoutVin
1 real (-infin infin)
Phase reference phase in degrees 00 deg real (-infin infin)
GainImbalance gain imbalance in dB Qchannel relative to I channel
00 real (-infin infin)
PhaseImbalance phase imbalance in degrees Qchannel relative to I channel
00 real (-infin infin)
Rate data rate Mbps_55 Mbps_11 Mbps_55 enum
PLCPType PLCP preamble type LongShort
Long enum
Octets octet number of PSDU 100 int (0 2312)
InitPhase initial phase of DBPSK 0785 real (0 2π )
ScramblerInit initial state of scrambler 1 1 0 1 1 0 0 intarray
0 1dagger
PwrType power on and off ramp typeNone Linear Cosine
None enum
RampTime power on and off ramp time 20usec sec real [0usec 1000usec]
SampsPerChip number of samples per chip 2 int [2 8]
IdleInterval idle time 500usec sec real [0usec 1000usec]
FilterType pulse-shaping filter typeRectangle Gaussian Root-Cosine Off
Off enum
Taps number of taps 6 int [1 1000]
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Alpha roll-off factor for root raised-cosine filter
05 real [0 10]
BT product of 3dB bandwidth andsymbol time for Gaussian filter
05 real (0 10)
MaxSearchDelay time range for searching fadingpath
30usec sec real [3usec 10usec]
FingerNumber number of rake receiver fingers 3 int [1 30]
FreqEstWindow number of preamble symbolsused to estimate frequencyoffset
20 int [1 128] if PLCPType=Long[1 56] if PLCPType=Short
SyncEstWindow number of preamble symbolsused for burst synchronization
20 int [1 128] if PLCPType=Long[1 56] if PLCPType=Short
EquAlgorithm algorithm for equalizer RLSLMS
RLS enum
FwdTaps number of forward taps inequalizer
5 int [1 256]
FbkTaps number of feedback taps inequalizer
3 int [1 128]
EquAlpha scale factor for LMS algorithm 00004 real (00 10)
Lambda weighting factor for RLSalgorithm
0999 real (00 10)
Delta small positive constant for RLSalgorithm
0001 real (00 100)
DownSamplePhase phase of down sample modelwith range from 0 toSampsPerChip-1
0 int [00 SampsPerChip-1]
FreqOffset actual frequency offset 00 Hz real (-infin infin)
dagger for each array element array size must be 7
Pin Input
Pin Name Description Signal Type
1 RF_Signal RF signals timed
Pin Output
Pin Name Description Signal Type
2 PSDU demodulated PSDU after CCK receiver int
3 Header demodulated header after CCK receiver int
4 Preamble demodulated preamble after CCKreceiver
int
5 BurstOut 11b CCK burst after DFE receiver complex
NotesEquations
This subnetwork provides the full CCK receiver according to the IEEE 80211b1Standard it can be configured in a top-level design using model parametersThis subnetwork integrates an RF demodulator and baseband receiver The schematic2is shown in the following figure
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WLAN_CCK_RF_Rx_DFE Schematic
Receiver functions are implemented as specified in the IEEE 80211b Standard
Start of frame is detected (WLAN_11bBurstSync)Carrier frequency offsets are estimated (WLAN_FreqEstimator)The packet is derotated according to estimated frequency offset(WLAN_11bDemuxBurst in the WLAN_11b_Equalizer subnetwork)The received packet is equalized by the decision feedback equalizer(WLAN_11bDFE in the WLAN_11b_Equalizer subnetwork)The equalized signal is demultiplexed into PSDU Header and Preamble partsHeader and Preamble parts are Barker despreadPSDU parts are CCK demodulatedDespread Preamble and Header and CCK-demodulated PSDU are multiplexedinto one bit stream the bit stream is then descrambledThe descrambled bit stream is demultiplexed into PSDU Preamble and Headerbits and outputThe equalized burst (BurstOut) is outputThe WLAN_CCK_Rx_DFE receiver schematic is shown in the following figure
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WLAN_CCK_Rx_DFE Schematic
References
IEEE Standard 80211b-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer Extension in the24 GHz Band 1999IEEE Standard 80211-1999 Part 11 Wireless LAN Medium Access Control (MAC)2and Physical Layer (PHY) specifications 1999John G Proakis Digital Communications Third Edition page 636-679 McGraw-Hill31995John G Proakis Adaptive Equalization for TDMA Digital Mobile Radio IEEE Trans on4Vehicular Technology page 333-341 Vol 40 No2 May 1991
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WLAN_CCK_RF_Rx_Rake
Description 80211b CCK Rake receiverLibrary WLAN 11b ReceiverClass TSDFWLAN_CCK_RF_Rx_Rake
Parameters
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Name Description Default Unit Type Range
RIn input resistance DefaultRIn Ohm real (0 infin )
ROut output resistance DefaultROut Ohm real (0 infin )
RTemp physical temperature in degrees C DefaultRTemp Ohm real [-27315 infin )
RefFreq internal reference frequency 2400MHz Hz real (0 infin)
Sensitivity voltage output sensitivity VoutVin 1 real (-infin infin )
Phase reference phase in degrees 00 deg real (-infin infin)
GainImbalance gain imbalance in dB Q channel relativeto I channel
00 real (-infin infin)
PhaseImbalance phase imbalance in degrees Q channelrelative to I channel
00 real (-infin infin)
Rate data rate Mbps_55 Mbps_11 Mbps_55 enum
PLCPType PLCP preamble type Long Short Long enum
Octets octet number of PSDU 100 int (0 2312]
InitPhase initial phase of DBPSK 0785 real [0 2π )
ScramblerInit initial state of scrambler 1 1 0 1 1 0 0 intarray
0 1 dagger
PwrType power on and off ramp type NoneLinear Cosine
None enum
RampTime power on and off ramp time 20usec sec real [0usec 1000usec]
SampsPerChip number of samples per chip 2 int [2 8]
IdleInterval idle time 500usec sec real [10usec 1000usec]
FilterType pulse-shaping filter type RectangleGaussian Root-Cosine Off
Off enum
Taps number of taps 6 int [1 1000]
Alpha roll-off factor for root raised-cosine filter 05 real (0 10]
BT product of 3dB bandwidth and symboltime for Gaussian filter
05 real (0 10]
MaxSearchDelay time range for searching fading path 30usec sec real [3usec 10usec]
FingerNumber number of rake receiver fingers 3 int [1 30]
CIREstWindow number of preamble symbols used toestimate channel
20 int [1 128] ifPLCPType=Long[1 56] ifPLCPType=Short
FreqEstWindow number of preamble symbols used toestimate frequency offset
20 int [1 128] ifPLCPType=Long[1 56] ifPLCPType=Short
SyncEstWindow number of preamble symbols used forburst synchronization
20 int [1 128] ifPLCPType=Long[1 56] ifPLCPType=Short
FreqOffset actual frequency offset 00 Hz real (-infin infin)
dagger for each array element array size must be 7
Pin Inputs
Pin Name Description Signal Type
1 RF_Signal RF signals timed
Pin Outputs
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Pin Name Description Signal Type
2 PSDU demodulated PSDU after CCK receiver int
3 Header demodulated header after CCK receiver int
4 Preamble demodulated preamble after CCKreceiver
int
5 BurstOut 11b CCK burst after Rake receiver complex
NotesEquations
This subnetwork provides the full CCK receiver according to the IEEE 80211b1Standard it incorporates rake combination and can be configured in a top-leveldesign using model parametersThis subnetwork integrates an RF demodulator and baseband receiver the schematicis shown in the following figure
WLAN_CCK_RF_Rx_Rake Schematic
Receiver functions are implemented as specified in the IEEE 80211b Standard2Start of frame is detected (WLAN_11bBurstSync)Carrier frequency offsets are estimated (WLAN_FreqEstimator)The packet is derotated according to estimated frequency offset(WLAN_FcCompensator)The received packets are rake combined (WLAN_11bRake)The rake combined signal is demultiplexed into PSDU Header and PreamblepartsPreamble and Header parts are Barker despreadPSDU parts are CCK demodulatedPreamble Header and CCK are then multiplexed into one bit stream the bitstream is then descrambledThe descrambled bit stream is demultiplexed into PSDU Preamble and Headerbits these parts are outputThe rake-combined burst is outputThe WLAN_CCK_Rx_Rake receiver schematic is shown in the following figure
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WLAN_CCK_Rx_Rake Schematic
References
IEEE Standard 80211b-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer Extension in the24 GHz Band 1999IEEE Standard 80211-1999 Part 11 Wireless LAN Medium Access Control (MAC)2and Physical Layer (PHY) specifications 1999John G Proakis Digital Communications Third Edition page 636-679 McGraw-Hill31995
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WLAN_CCK_Rx_DFE
Description 80211b CCK receiver with equalizerLibrary WLAN 11b ReceiverClass SDFWLAN_CCK_Rx_DFE
Parameters
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Name Description Default Unit Type Range
Rate data rate Mbps_55 Mbps_11 Mbps_55 enum
PLCPType PLCP preamble type Long Short Long enum
Octets octet number of PSDU 100 int (0 2312]
InitPhase initial phase of DBPSK 0785 real [0 2π )
ScramblerInit initial state of scrambler 1 1 0 1 1 00
intarray
0 1dagger
PwrType power on and off ramp type NoneLinear Cosine
None enum
RampTime power on and off ramp time 20microsec sec real [0microsec 1000microsec]
SampsPerChip number of samples per chip 2 int [2 8]
IdleInterval idle time 500microsec sec real [0microsec 1000microsec]
FilterType pulse-shaping filter type RectangleGaussian Root-Cosine Off
Off enum
Taps number of taps 6 int [1 1000]
Alpha roll-off factor for root raised-cosine filter 05 real (0 10]
BT product of 3dB bandwidth and symboltime for Gaussian filter
05 real (0 10]
MaxSearchDelay time range for searching fading path 30microsec sec real [3microsec 10microsec]
FingerNumber number of rake receiver fingers 3 int [1 30]
FreqEstWindow number of preamble symbols used toestimate frequency offset
20 int [1 128] ifPLCPType=Long[1 56] ifPLCPType=Short
SyncEstWindow number of preamble symbols used forburst synchronization
20 int [1 128] ifPLCPType=Long[1 56] ifPLCPType=Short
EquAlgorithm algorithm for equalizer RLS LMS RLS enum
FwdTaps number of forward taps in equalizer 5 int [1 256]
FbkTaps number of feedback taps in equalizer 3 int [1 128]
EquAlpha scale factor for LMS algorithm 00004 real (00 10)
Lambda weighting factor for RLS algorithm 0999 real (00 10)
Delta small positive constant for RLS algorithm 0001 real (00 100]
DownSamplePhase phase of down sample model(0SampsPerChip-1)
0 int [00 SampsPerChip-1]
FreqOffset actual frequency offset 00 Hz real (-infin infin)
dagger for each array element array size must be 7
Pin Inputs
Pin Name Description Signal Type
1 BurstIn received burst complex
Pin Outputs
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Pin Name Description Signal Type
2 PSDU demodulated PSDU after CCK receiver int
3 Header demodulated header after CCK receiver int
4 Preamble demodulated preamble after CCKreceiver
int
5 BurstOut 11b CCK burst after DFE receiver complex
NotesEquations
This subnetwork implements an 80211b CCK receiver with decision feedback1equalizer It performs burst synchronization carrier frequency synchronizationdecision feedback equalization Barker despreading CCK demodulation anddescrambling The schematic is shown in the following figure
WLAN_CCK_Rx_DFE Schematic
This subnetwork outputs both the demodulated PSDU Header Preamble and the full2PPDU frame after equalizer The PPDU frames are illustrated in the following figuresOne PPDU frame includes PLCP Preamble PLCP Header and PSDU
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Long PLCP PPDU Format
Short PLCP PPDU Format
References
IEEE Standard 80211b-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer Extension in the24 GHz Band 1999IEEE Standard 80211-1999 Part 11 Wireless LAN Medium Access Control (MAC)2and Physical Layer (PHY) specifications 1999John G Proakis Digital Communications Third Edition page 636-679 McGraw-Hill31995John G Proakis Adaptive Equalization for TDMA Digital Mobile Radio IEEE Trans on4Vehicular Technology page 333-341 Vol 40 No2 May 1991
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WLAN_CCK_Rx_Rake
Description 80211b CCK Rake receiverLibrary WLAN 11b ReceiverClass SDFWLAN_CCK_Rx_Rake
Parameters
Name Description Default Unit Type Range
Rate data rate Mbps_55 Mbps_11 Mbps_55 enum
PLCPType PLCP preamble type Long Short Long enum
Octets octet number of PSDU 100 int (0 2312]
InitPhase initial phase of DBPSK 0785 real [0 2π )
ScramblerInit initial state of scrambler 1 1 0 1 1 00
intarray
0 1dagger
PwrType power on and off ramp type None LinearCosine
None enum
RampTime power on and off ramp time 20microsec sec real [0microsec 1000microsec]
SampsPerChip number of samples per chip 2 int [2 8]
IdleInterval idle time 500microsec sec real [10microsec 1000microsec]
FilterType pulse-shaping filter type RectangleGaussian Root-Cosine Off
Off enum
Taps number of taps 6 int [1 1000]
Alpha roll-off factor for root raised-cosine filter 05 real (0 10]
BT product of 3dB bandwidth and symbol timefor Gaussian filter
05 real (0 10]
MaxSearchDelay time range for searching fading path 30microsec sec real [3microsec 10microsec]
FingerNumber number of rake receiver fingers 3 int [1 30]
CIREstWindow number of preamble symbols used toestimate channel
20 int [1 128] ifPLCPType=Long[1 56] ifPLCPType=Short
FreqEstWindow number of preamble symbols used toestimate frequency offset
20 int [1 128] ifPLCPType=Long[1 56] ifPLCPType=Short
SyncEstWindow number of preamble symbols used forburst synchronization
20 int [1 128] ifPLCPType=Long[1 56] ifPLCPType=Short
FreqOffset actual frequency offset 00 Hz real (-infin infin)
dagger for each array element array size must be 7
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Pin Inputs
Pin Name Description Signal Type
1 BurstIn received burst complex
Pin Outputs
Pin Name Description Signal Type
2 PSDU demodulated PSDU after CCK receiver int
3 Header demodulated header after CCK receiver int
4 Preamble demodulated preamble after CCKreceiver
int
5 BurstOut 11b CCK burst after Rake receiver complex
NotesEquations
This subnetwork implements an 80211b CCK receiver with rake combination It1performs burst synchronization carrier frequency synchronization rake combinationBarker despreading CCK demodulation and descrambling The schematic is shown inthe following figure
WLAN_CCK_Rx_Rake Schematic
This subnetwork outputs both the demodulated PSDU Header Preamble and the full2PPDU frame after rake combination The PPDU frames are illustrated in the followingfigures One PPDU frame includes PLCP Preamble PLCP Header and PSDU
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Long PLCP PPDU Format
Short PLCP PPDU Format
References
IEEE Standard 80211b-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer Extension in the24 GHz Band 1999IEEE Standard 80211-1999 Part 11 Wireless LAN Medium Access Control (MAC)2and Physical Layer (PHY) specifications 1999John G Proakis Digital Communications Third Edition page 636-679 McGraw-Hill31995
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WLAN_Despreader
Description 11b barker despreaderLibrary WLAN 11b ReceiverClass SDFWLAN_Despreader
Pin Inputs
Pin Name Description Signal Type
1 input input Barker spreading signal complex
Pin Outputs
Pin Name Description Signal Type
2 output output signal after Braker de-spreading
complex
NotesEquations
This model is used to implement Barker despreader for 80211b Each firing 11 input1tokens make the Barker despreader and one despread signal is outputThe 11-chip Barker sequence2
is used as the PN code sequence for 1 and 2 Mbits modulation
= +1 -1 +1 +1 -1 +1 +1 +1 -1 -1 -1
The Barker spreading signal sequence is
The despreader calculates the despreading signal as follows then outputs y
References
IEEE Standard 80211b-1999 Part 11 Wireless LAN Medium Access Control (MAC)1
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and Physical Layer (PHY) specifications High-speed Physical Layer Extension in the24 GHz Band 1999IEEE Standard 80211-1999 Part 11 Wireless LAN Medium Access Control (MAC)2and Physical Layer (PHY) specifications 1999
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WLAN_FcCompensator
Description 11b carrier frequency compensatorLibrary WLAN 11b ReceiverClass SDFWLAN_FcCompensatorDerived From WLAN_11bBase
Parameters
Name Description Default Unit Type Range
MaxSearchDelay time range for searching fading path 30microsec sec real [3microsec 10microsec]
SampsPerChip number of samples per chip 2 int [2 8]
Rate data rate Mbps_1 Mbps_2 Mbps_55 Mbps_11 Mbps_55 enum
PLCPType PLCP preamble type Long Short Long enum
Octets octet number of PSDU 100 int (0 2312]
PwrType power on and off ramp type None LinearCosine
None enum
RampTime power on and off ramp time 20microsec sec real [0microsec 1000microsec]
ModType modulation type CCK PBCC CCK enum
IdleInterval idle time 500microsec sec real [10microsec1000microsec]
FreqOffset actual frequency offset 00 Hz real (-infin infin)
Pin Inputs
Pin Name Description Signal Type
1 BurstIn the 11b received signal complex
2 DeltaF estimated frequencyoffset
real
Pin Outputs
Pin Name Description Signal Type
3 BurstOut 11b signal compensated with freq offset complex
4 PLCP compensated PLCP is to be used as input of channel estimation model complex
NotesEquations
This model compensates for carrier frequency offset1Each firing the frequency offset detected by WLAN_11bFreqEstimator is input at pinDeltaF and the frequency offset burst are input at pin BurstIn The burst is thencompensated by multiplying exp(-j times 2 times PI times DeltaF times n times Ts) and output at pinBurstOut where n is the number of burst samples from 1 to entire burst length andTs is sample time interval (described in note 3) Pin PLCP is the compensated PCLPsignal
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Each firing the tokens consumed by BurstIn can be calculated as follows
(RampTime times 2+IdleInterval) times 11E6 times SampsPerChip+DataLength
where
DataLength = (NPLCP+NSYM) times SampsPerChip
if PLCPType=Long (NPLCP=(144+48) times 11)else (NPLCP=(72+24) times 11)if Rate=1M (NSYM=Octets times 8 times 11)if Rate=2M (NSYM=Octets times 4 times 11)if Rate=55M (NSYM=Octets times 8 times 2)if Rate=11M ((NSYM=Octets times 8)The same number of tokens are simultaneously produced by pin BurstOutThe MaxSearchDelay value range for searching fading channels must be set larger2than the sum of system delay and maximum multipath delayThe transmitter transmits burst-by-burst in ADS The burst sequence is a continuous3stream (The 80211 burst is transmitted burst-by-burst) The transmittedconsecutive bursts are independentThe estimated frequency offset (Δ f i ) of each received burst is input at DeltaF To
avoid estimated frequency offset impacting the next bursts in the frequencycompensator the FreqOffset parameter in this model is set as the actual frequencyoffset between transmitter and receiver When the ith burst is processed the actualphase of previous i-1 bursts is calculated and removed by FreqOffset The ithestimated frequency offset (Δ f i ) is used to compensate for the phase in current
burst onlyAssume x 0 x 1 x Total -1 sequences are the BurstIn burst signals after
removing the actual phase of previous i -1 bursts caused by the actual frequencyoffset from FreqOffset The y 0 y 1 y Total -1 sequences (whose phase caused
by frequency offset) are removed
where
Δ f i is frequency offset of ith received burst which is the input at DeltaF
is the sample time interval in 80211b system
References
IEEE Standard 80211b-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer Extension in the24 GHz Band 1999IEEE Standard 80211-1999 Part 11 Wireless LAN Medium Access Control (MAC)2and Physical Layer (PHY) specifications 1999
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WLAN_HeaderDemap
Description Header demapperLibrary WLAN 11b ReceiverClass SDFWLAN_HeaderDemap
Parameters
Name Description Default Type
PLCPType PLCP preamble type LongShort
Long enum
Pin Inputs
Pin Name Description Signal Type
1 HeadIn PLCP header modulation signal complex
2 InitPhase initial signal from preamble demapper complex
Pin Outputs
Pin Name Description Signal Type
3 phase last complex mappingsignal
complex
4 HeadOut PLCP header signal int
NotesEquations
This model outputs the PLCP header demapping signal and phase The long PLCP1header uses 1 Mbits DBPSK modulation the short PLCP header uses 2 Mbits DQPSKmodulationThe initial phase of DBPSK or DQPSK signal is given by pin InitPhase DBPSK2encoding is listed in the following table
DBPSK Encoding
Bit input Phase change (+jw)
0 0
1 π
DQPSK encoding is listed in the following table
DQPSK Encoding
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Dibit pattern (d0d1) Phase change (+jw)
00 0
01 π2
11 π
10 3 times π2 (-π2)
References
IEEE Standard 80211b-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer Extension in the24 GHz Band 1999IEEE Standard 80211-1999 Part 11 Wireless LAN Medium Access Control (MAC)2and Physical Layer (PHY) specifications 1999
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WLAN_PhaseRotator
Description 11b phase rotator after decision feedback equalizerLibrary WLAN 11b ReceiverClass SDFWLAN_PhaseRotator
Parameters
Name Description Default Type Range
Rate data rate Mbps_1 Mbps_2 Mbps_55Mbps_11
Mbps_55 enum
ModType modulation type CCK PBCC CCK enum
PLCPType PLCP preamble type Long Short Long enum
Octets octet number of PSDU 100 int (0 2312]
Pin Inputs
Pin Name Description Signal Type
1 BurstIn input signal before phase compensator complex
Pin Outputs
Pin Name Description Signal Type
2 BurstOut output data after phase compensator complex
3 CommPhase common phase for the equalized signal real
NotesEquations
This model implements phase rotator after decision feedback equalizer for equalized180211b burstRate ModType PLCPType and Octets parameters are used to specify the number of2complex signals in one burst In the WLAN Design Library one real 80211b burstconsists of PLCP Preamble (Long or Short) PLCP Header (Long or Short) and PSDUThe length of PLCP Preamble (mPLCP) is determined by PLCPType parameter
The length of Header (mHeader) is determined by PLCPType parameter
The length of PSDU (mPSDU) is determined by Rate parameter
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So the total number of one 80211b burst is as follows
Each firing Total number of tokens were input in BurstIn and Total number of tokenswere output in BurstOut pinPin 1 (BurstIn) equalized sequences x 0 x 1 x Total -1 input pin 2 (BurstOut)3
sequences y 0 y 1 y Total -1 output after phase rotator removes the common
phase pin 3 (CommPhase) is the common phase of equalized sequence outputThis model must work behind WLAN_11bDFE when the equalizer converges The4constellation of CCK is the same as that of QPSK The PSDU and Header partsequalized signals are used to detect the common phase the Preamble part is notused it is used to train the coefficients of the equalizer and the equalizer algorithmdoes not converge The common phase detection algorithm works after the equalizerconverges the common phase detection algorithm is as follows
phase1 =00
phase2 =00
phase3 =00
phase4 =00
first_1 = 0
second_2 = 0
third_3 = 0
fourth_4 = 0
for (i=0 iltm_inlength-m_prmblengthi++)
Complex xx_
xx = BurstIn(Pin-)
if ((real(xx)gt00)ampamp(imag(xx)gt00))
phase1+=arg(xx)
first_1++
if ((real(xx)lt00)ampamp(imag(xx)gt00))
phase2+=arg(xx)
second_2++
if ((real(xx)lt00)ampamp(imag(xx)lt00))
phase3+=arg(xx)
third_3++
if ((real(xx)gt00)ampamp(imag(xx)lt00))
phase4+=arg(xx)
fourth_4++
phase1 = phase1first_1
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phase1 = phase1-PI4
phase2 = phase2second_2
phase2 = phase2-3PI4
phase3 = phase3third_3
phase3 = phase3+3PI4
phase4 = phase4forth_4
phase4 = phase4+PI4
double phase
phase =(phase1+phase2+phase3+phase4)40
After getting the detected common phase φ above the common phase can beremoved by multiply e -jφ
y k = x k times e -jφ
References
IEEE Standard 80211b-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer Extension in the24 GHz Band 1999IEEE Standard 80211-1999 Part 11 Wireless LAN Medium Access Control (MAC)2and Physical Layer (PHY) specifications 1999
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WLAN_PrmblDemap
Description Preamble demapperLibrary WLAN 11b ReceiverClass SDFWLAN_PrmblDemap
Parameters
Name Description Default Type Range
PLCPType PLCP preamble type LongShort
Long enum [0 1]
InitPhase initial phase of DBPSK PI 4 real [0 2π )
Pin Inputs
Pin Name Description Signal Type
1 PrmblIn DBPSK signal complex
Pin Outputs
Pin Name Description Signal Type
2 phase last DBPSK signal complex
3 PrmblOut PLCP preamble signal int
NotesEquations
This model outputs the PLCP preamble demapping bits and the last complex signal1Both long PLCP preamble and short PLCP preamble use 1 Mbits DBPSK modulationThe InitPhase parameter specifies the initial phase of the DBPSK signal DBPSKencoding is given in the following table
DBPSK Encoding
Bit Input Phase Change (+jw)
0 0
1 π
References
IEEE Standard 80211b-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer Extension in the24 GHz Band 1999IEEE Standard 80211-1999 Part 11 Wireless LAN Medium Access Control (MAC)2and Physical Layer (PHY) specifications 1999
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WLAN_RecFilter
Description Receiver matched filterLibrary WLAN 11b ReceiverClass SDFWLAN_RecFilter
Parameters
Name Description Default Unit Type Range
FilterType receiver matched filter type Rectangle GaussianRoot-Cosine Off
Off enum
Taps number of taps 6 int [1 1000]
SampsPerChip samples per chip 2 int [2 8]
Alpha roll-off factor for root raised-cosine filter 05 real (0 10]
BT product of 3dB bandwidth and symbol time forGaussian filter
05 real (0 10]
Rate data rate Mbps_1 Mbps_2 Mbps_55 Mbps_11 Mbps_55 enum
ModType modulation type CCK PBCC CCK enum
PLCPType PLCP preamble type Long Short Long enum
Octets octet number of PSDU 100 int (0 2312]
RampTime power on and off ramp time 20usec sec real [0usec1000usec]
PwrType power on and off ramp type None Linear Cosine None enum
IdleInterval idle time 500usec sec real [10usec1000usec]
Pin Inputs
Pin Name Description Signal Type
1 DataIn input data complex
Pin Outputs
Pin Name Description Signal Type
2 DataOut output data complex
NotesEquations
This receiver model matches the transmitter filter Each firing data from the RF1demodulator with ramp PPDU and idle is input data is then filtered sample-by-sampleIf FilterType=Off the input signal will flow directly without filtering If the transmittershaping filter is set to Root-Cosine set the receiver filter to Root-Cosine to obtain anISI-free signal if the transmitter shaping filter is set to another filter type set thereceiver filter to Off to avoid additional ISIThe impulse response of the rectangle filter can be given by
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2
where Ts is symbol intervalThe impulse response of Gaussian filter can be given by3
and
where BT is the BT parameter and Ts is the symbol intervalThe impulse response of raised-cosine rolloff filter can be given by4
where α is the Alpha parameter and Ts is the symbol intervalThe impulse response of the root raised-cosine filter has the following relationship5with the raised-cosine filter
h ( n ) = h 1( n ) ƒ h 1( n )
where h(n) is the impulse response of raised filter and h1(n) is root-raisedThis filter does not implement interpolating or decimating operations The output6signal has the same sample rate as the input signalTaps is the filter length and specifies the number of symbol periods to be used in the7calculation of the symbolAlpha specifies the sharpness of a root cosine filter when FilterType=Root-Cosine8BT is the Gaussian filter coefficient it specifies the extent of signal filtering B is the93 dB bandwidth of the filter T is the duration of the symbol period Common valuesfor BT are 03 to 05Rate specifies the transmitted data rate10PLCPType specifies the format of the preambleheader sections of the framed signal11Octets specifies the number of data bytes per burst (note that it is in bytes to12transform the value into bits multiply by 8)RampTime specifies the length (in microseconds) of the power updown ramp it is13used when PwrType is Linear or CosinePwrType specifies the pattern for generating the ramp signal None Linear or14Cosine The Cosine ramp gives the least amount of out-of-channel interference Nonestarts transmitting the signal at full power (it is the simplest power ramp toimplement) and the Linear ramp shapes the burst in a linear fashion
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11b Signal SourcesWLAN 11bCCK RF (wlan)WLAN 11bCCKSignalSrc (wlan)WLAN 11bCCKSignalSrc1 (wlan)WLAN 11bMuxBurst (wlan)WLAN 11bPBCCSignalSrc (wlan)WLAN 11bScrambler (wlan)WLAN 11SignalSrc (wlan)WLAN 802 11bRF (wlan)WLAN Barker (wlan)WLAN CCKMod (wlan)WLAN CRC (wlan)WLAN HeaderMap (wlan)WLAN IdlePadding (wlan)WLAN MuxPLCP (wlan)WLAN PBCCConvCoder (wlan)WLAN PBCCMod (wlan)WLAN PLCPHeader (wlan)WLAN PLCPPreamble (wlan)WLAN PreambleMap (wlan)WLAN PSDUMap (wlan)WLAN TransFilter (wlan)
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WLAN_11bCCK_RF
Description RF Signal source of IEEE 80211b with idle and CCK modulationLibrary WLAN 11b Signal SourceClass TSDFWLAN_11bCCK_RF
Parameters
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Name Description Default Unit Type Range
ROut output resistance DefaultROut Ohm real (0 infin)
FCarrier carrier frequency 2400MHz Hz real (0 infin)
Power modulator output power 40mW W real [0 infin)
VRef reference voltage for output power calibration 01122V V real (0 infin)
PhasePolarity if set to Invert Q channel signal is invertedNormal Invert
Normal enum
GainImbalance gain imbalance in dB Q channel relative to Ichannel
00 real (-infin infin)
PhaseImbalance phase imbalance in degrees Q channelrelative to I channel
00 real (-infin infin)
I_OriginOffset I origin offset in percent with respect to outputrms voltage
00 real (-infin infin)
Q_OriginOffset Q origin offset in percent with respect tooutput rms voltage
00 real (-infin infin)
IQ_Rotation IQ rotation in degrees 00 real (-infin infin)
NDensity noise spectral density at output in dBmHz -173975 real (-infin infin)
Type type of bit sequence random or pseudorandom Random Prbs
Random enum
ProbOfZero probability of bit value being zero (used whenType=Random)
05 real [0 1]
LFSR_Length Linear Feedback Shift Register length (usedwhen Type=Prbs)
12 int [2 31]
LFSR_InitState Linear Feedback Shift Register initial state(used when Type=Prbs)
1 int [1 pow (2LFSR_Length) -1]
Rate data rate Mbps_55 Mbps_11 Mbps_55 enum
PLCPType PLCP preamble type Long Short Long enum
Octets octet number of PSDU 100 int (0 2312]
ClocksBit locked clocks bit Not Locked Locked enum
InitPhase initial phase of DBPSK 0785 real [0 2π )
ScramblerInit initial state of scrambler 1 1 0 1 1 00
intarray
0 1dagger
PwrType power on and off ramp type None LinearCosine
None enum
RampTime power on and off ramp time 20microsec sec real [0microsec 1000microsec]
OverSampling sampling rate of pulse-shaping filter Ratio_2Ratio_3 Ratio_4 Ratio_5 Ratio_6 Ratio_7Ratio_8 Ratio_9
Ratio_2 enum
IdleInterval idle time 500microsec sec real [0microsec 1000microsec]
FilterType pulse-shaping filter type NoneFilterGaussian Root-Cosine Ideal-Lowpass
Gaussian enum
Taps number of taps 6 int [1 1000]
Alpha roll-off factor for root raised-cosine filter 05 real (0 10]
BT product of 3dB bandwidth and symbol time forGaussian filter
05 real (0 10]
dagger for each array element array size must be 7
Pin Outputs
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Pin Name Description Signal Type
1 RF_Burst RF signal of IEEE80211b burst withidle
timed
2 BurstPreFilter IEEE80211b burst without idle complex
3 Header header bits int
4 PLCP PLCP bits int
5 PSDU PSDU bits int
NotesEquations
This subnetwork is used to generate an RF signal the baseband signal is sent to an1IQ RF modulator and the RF signal is generated For ease of testing five signals areoutput
RF_Burst is RF signal of IEEE80211b burst with idleBurstPreFilter is the signal generated before the shaping filter (note that thissignal is digital)Header outputs the header bits according to IEEE80211bPLCP outputs the PLCP bits according to IEEE80211bPSDU outputs the payload data bits that are used in the BERPER test
This subnetwork integrates a baseband transmitter and RF modulator the schematic2is shown in the following figure
WLAN_11bCCK_RF Schematic
In this subnetwork the baseband generation block includes function blocks that areessential to the 11b baseband signal such as preamble header and PSDUgeneration signal scrambling DBPSK and DQPSK mapping CCK modulating ramptime and idle time attaching pulse shaping is attached as the final block to reducethe transmitted bandwidth thereby increasing spectral efficiencyThe IEEE 80211b CCK baseband signal is generated by the WLAN_11bCCKSignalSrc1subnetwork the schematic is shown in the following figure
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WLAN_11bCCKSignalSrc1 Schematic
Model TkIQrms and TkPower are used to calibrate the output power When these are3activated and simulated the result shown in input IQ signal rms value should bethe VRef for WLAN_11bCCK_RF If VRef is set correctly the output power is thedesignated Power as can be seen in the Modulator output power in dBmThe GainImbalance PhaseImbalance I_OriginOffset Q_OriginOffset and4IQ_Rotation parameters are used to add certain impairments to the ideal output RFsignal Impairments are added in the order described hereThe unimpaired RF I and Q envelope voltages have gain and phase imbalanceapplied The RF is given by
where A is a scaling factor that depends on the Power and ROut parameters specifiedby the designer V I( t ) is the in-phase RF envelope V Q( t ) is the quadrature phaseRF envelope g is the gain imbalance
and φ (in degrees) is the phase imbalanceNext the signal V RF( t ) is rotated by IQ_Rotation degrees The I_OriginOffset andQ_OriginOffset are then applied to the rotated signal Note that the amountsspecified are percentages with respect to the output rms voltage The output rmsvoltage is given by
The PhasePolarity parameter is used to invert the polarity of the Q channel signal5before modulation Depending on the configuration and number of mixers in thetransmitter and receiver the output of the demodulator may be inverted If such aconfiguration is used the Q channel signal can be correctly recovered by setting this
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parameter to InvertThe VRef parameter is used to calibrate the modulator VRef is the input voltage6value that results in an instantaneous output power on a matched load equal to P Inorder to get an average output power on a matched load equal to P the input rmsvoltage must equal VRef Therefore in order to calibrate the modulator VRef mustbe set to the input rms voltageRate is used to determine the transmitted data rate It can be chosen from the lists7of 55 Mbps and 11 MbpsPLCPType is used to select the format of the preambleheader sections of the framed8signal Long and Short can be selectedOctets indicates data bytes per burst (note that it is in bytes to transform it into9bits multiply by 8)ClocksBit enables users to toggle the clock locked flag in the header This is Bit 2 in10the Service field of the PPDU frame it is used to indicate to the receiver if the carrierand the symbol clock use the same local oscillator and the designer can set this bitIf ClocksBit=Locked the clock bit is 1 (otherwise it is 0)InitPhase specifies the initial phase of the DBPSK signal The default value is set to11PI40ScramblerInit indicates the initial state of scrambler in WLAN 11b specification this12value is set to 1101100PwrType specifies the pattern for generating the ramp signal None Linear or13Cosine The Cosine ramp gives the least amount of out-of-channel interference Nonestarts transmitting the signal at full power (it is the simplest power ramp toimplement) and the Linear ramp shapes the burst in a linear fashionRampTime specifies the length (in microseconds) of the power updown ramp it is14used when PwrType is Linear or CosineOverSampling indicates the oversampling ratio of transmission signal For example if15OverSampling = Ratio_4 the transmission signal is upsampled with 4 timesOversampling ratios from 2 to 9 are supportedIdleInterval indicates the idle time added between two consecutive bursts which is in16[0 1000 microsec]FilterType specifies a baseband filter that is used to reduce the transmitted17bandwidth thereby increasing spectral efficiency The 80211b specification does notspecify what type of filter must be used but the transmitted signal must meet thespectral mask requirements FilterType options are
NoneFilter No transmitter filter is usedGaussian The Gaussian filter does not have zero ISI Wireless system architectsmust determine just how much of the inter-symbol interference can be toleratedin a system and combine that with noise and interference The Gaussian filter isGaussian-shaped in both the time and frequency domains it does not ring likethe root-cosine filters ring The effects of this filter in the time domain arerelatively short and each symbol interacts significantly (or causes ISI) with onlythe preceding and succeeding symbols This reduces the tendency for particularsequences of symbols to interact which makes amplifiers easier to build andmore efficientRoot-Cosine Root-cosine filters (also referred to as square root raised-cosinefilters) have the property that their impulse response rings at the symbol rateAdjacent symbols do not interfere with each other at the symbol times becausethe response equals zero at all symbol times except the center (desired) oneRoot-cosine filters heavily filter the signal without blurring the symbols togetherat the symbol times This is important for transmitting information withouterrors caused by ISI Note that ISI does exist at all times except at symbol(decision) timesIdeal-Lowpass In the frequency domain this filter appears as a lowpass
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rectangular filter with very steep cut-off characteristics The passband is set toequal the symbol rate of the signal Due to a finite number of coefficients thefilter has a predefined length and is not truly ideal The resulting ripple in thecut-off band is effectively minimized with a Hamming window A symbol lengthof 32 or greater is recommended for this filter
Taps is the filter length and determines how many symbol periods will be used in the18calculation of the symbol The filter selection influences the value of Taps
The Gaussian filter has a rapidly decaying impulse response so a filter length of6 is recommended Greater lengths have negligible effects on the accuracy ofthe signalThe root-cosine filter has a slowly decaying impulse response A filter length ofapproximately 32 is recommended Beyond this the ringing has negligibleeffects on the accuracy of the signalThe ideal lowpass filter also has a very slow decaying impulse response A filterlength of 32 or greater is recommendedFor both root-cosine and ideal lowpass filters the greater the filter length thegreater the accuracy of the signal
Alpha is to set the sharpness of a root-cosine filter when FilterType=Root-Cosine19BT is the Gaussian filter coefficient The B is the 3 dB bandwidth of the filter and T is20the duration of the symbol period BT determines the extent of the filtering of thesignal Common values for BT are 03 to 05
References
IEEE Standard 80211b-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer Extension in the24 GHz Band 1999
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WLAN_11bCCKSignalSrc
Description Signal source of IEEE 80211b with idle and CCK modulationLibrary WLAN 11b Signal SourceClass SDFWLAN_11bCCKSignalSrc
Parameters
Name Description Default Unit Type Range
Rate data rate Mbps_55 Mbps_11 Mbps_55 enum
PLCPType PLCP preamble type Long Short Long enum
Octets octet number of PSDU 100 int (0 2312]
ClocksBit locked clocks bit Not Locked Locked enum
InitPhase initial phase of DBPSK 0785 real [0 2π )
ScramblerInit initial state of scrambler 1 1 0 1 1 00
intarray
0 1dagger
PwrType power on and off ramp type None Linear Cosine None enum
RampTime power on and off ramp time 20microsec sec real [0microsec1000microsec]
OverSampling sampling rate of pulse-shaping filter Ratio_2 Ratio_3Ratio_4 Ratio_5 Ratio_6 Ratio_7 Ratio_8 Ratio_9
Ratio_2 enum
IdleInterval idle time 500microsec sec real [0microsec1000microsec]
FilterType pulse-shaping filter type NoneFilter Gaussian Root-Cosine Ideal-Lowpass
Gaussian enum
Taps number of taps 6 int [1 1000]
Alpha roll-off factor for root raised-cosine filter 05 real (0 10]
BT product of 3dB bandwidth and symbol time forGaussian filter
05 real (0 10]
dagger for each array element array size must be 7
Pin Inputs
Pin Name Description Signal Type
1 PSDU PSDU bits int
Pin Outputs
Pin Name Description Signal Type
2 burst IEEE80211b burst complex
NotesEquations
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This model is used to generate a CCK baseband signal according to IEEE 80211b1Functions are implemented that are essential to an 11b baseband signal includingpreamble header and PSDU generation signal scrambling DBPSK and DQPSKmapping CCK modulation ramp time and idle time attaching pulse shaping isattached to reduce the transmitted bandwidth thereby increasing spectral efficiencyThe schematic is shown in the following figure
WLAN_80211bCCKSignalSrc Schematic
Rate is used to determine the transmitted data rate It can be chosen from the lists2of 55 Mbps and 11 MbpsPLCPType is used to select the format of the preambleheader sections of the framed3signal Long and Short can be selectedOctets indicates data bytes per burst (note that it is in bytes to transform it into4bits multiply by 8)ClocksBit enables users to toggle the clock locked flag in the header This is Bit 2 in5the Service field of the PPDU frame This bit is used to indicate to the receiver if thecarrier and the symbol clock use the same local oscillator and the designer can setthis bit If ClocksBit=Locked the clock bit is 1 (otherwise it is 0)The InitPhase parameter specifies the initial phase of the DBPSK signal The default6value is PI40ScramblerInit indicates the initial state of scrambler in WLAN 11b specification this7value is 1101100PwrType specifies the pattern for generating the ramp signal None Linear or8Cosine The Cosine ramp gives the least amount of out-of-channel interference Nonestarts transmitting the signal at full power (it is the simplest power ramp toimplement) and the Linear ramp shapes the burst in a linear fashion
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RampTime specifies the length (in microseconds) of the power updown ramp it is9used when PwrType is Linear or CosineOverSampling indicates the oversampling ratio of transmission signal For example if10OverSampling = Ratio_4 the transmission signal is upsampled with 4 timesOversampling ratios ranging from 2 to 9 are supportedIdleInterval indicates the idle time added between two consecutive bursts which is in11[0 1000 microsec]FilterType specifies a baseband filter to be applied to reduce the transmitted12bandwidth thereby increasing spectral efficiency The 80211b specification does notspecify what type of filter must be used but the transmitted signal must meet thespectral mask requirements FilterType options are
NoneFilter No transmitter filter is usedGaussian The Gaussian filter does not have zero ISI Wireless system architectsmust determine just how much of the ISI can be tolerated in a system andcombine that with noise and interference The Gaussian filter is Gaussian shapedin both the time and frequency domains and it does not ring like root-cosinefilters ring The effects of this filter in the time domain are relatively short andeach symbol interacts significantly (or causes ISI) with only the preceding andsucceeding symbols This reduces the tendency for particular sequences ofsymbols to interact which makes amplifiers easier to build and more efficientRoot-Cosine Root-cosine filters (also referred to as square root raised-cosinefilters) have the property that their impulse response rings at the symbol rateAdjacent symbols do not interfere with each other at the symbol times becausethe response equals zero at all symbol times except the center (desired) oneRoot-cosine filters heavily filter the signal without blurring the symbols togetherat the symbol times This is important for transmitting information withouterrors caused by ISI Note that ISI does exist at all times except the symbol(decision) timesIdeal-Lowpass In the frequency domain this filter appears as a lowpassrectangular filter with very steep cut-off characteristics The passband is set toequal the symbol rate of the signal Due to a finite number of coefficients thefilter has a predefined length and is not truly ideal The resulting ripple in thecut-off band is effectively minimized with a Hamming window A symbol lengthof 32 or greater is recommended for this filter
Taps is the filter length and determines how many symbol periods will be used in the13calculation of the symbol The filter selection influences the value of TapsThe Gaussian filter has a rapidly decaying impulse response so a filter length of 6 isrecommended Greater lengths have negligible effects on the accuracy of the signalThe root-cosine filter has a slowly decaying impulse response A filter length ofapproximately 32 is recommended beyond this the ringing has negligible effects onthe accuracy of the signalThe ideal lowpass filter also has a very slow decaying impulse response A filterlength of 32 or greater is recommendedFor both root-cosine and ideal lowpass filters the greater the filter length thegreater the accuracy of the signalAlpha is to set the sharpness of a root-cosine filter when FilterType=Root-Cosine14BT is the Gaussian filter coefficient B is the 3 dB bandwidth of the filter and T is the15duration of the symbol period BT determines the extent of the filtering of the signalCommon values for BT are 03 to 05As illustrated in the following figures one PPDU frame includes PLCP Preamble PLCP16Header and PSDU
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Long PLCP PPDU Format
Short PLCP PPDU Format
References
IEEE Standard 80211b-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer Extension in the24 GHz Band 1999IEEE Standard 80211-1999 Part 11 Wireless LAN Medium Access Control (MAC)2and Physical Layer (PHY) specifications 1999
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WLAN_11bCCKSignalSrc1
Description Signal source of IEEE 80211b with idle and CCK modulationLibrary WLAN 11b Signal SourceClass SDFWLAN_11bCCKSignalSrc1
Parameters
Name Description Default Unit Type Range
Rate data rate Mbps_55 Mbps_11 Mbps_55 enum
PLCPType PLCP preamble type Long Short Long enum
Octets octet number of PSDU 100 int (0 2312]
ClocksBit locked clocks bit Not Locked Locked enum
InitPhase initial phase of DBPSK 0785 real [0 2π )
ScramblerInit initial state of scrambler 1 1 0 1 1 00
intarray
0 1dagger
PwrType power on and off ramp type None Linear Cosine None enum
RampTime power on and off ramp time 20microsec sec real [0microsec1000microsec]
OverSampling sampling rate of pulse-shaping filter Ratio_2 Ratio_3Ratio_4 Ratio_5 Ratio_6 Ratio_7 Ratio_8 Ratio_9
Ratio_2 enum
IdleInterval idle time 500microsec sec real [0microsec1000microsec]
FilterType pulse-shaping filter type NoneFilter Gaussian Root-Cosine Ideal-Lowpass
Gaussian enum
Taps number of taps 6 int [1 1000)
Alpha roll-off factor for root raised-cosine filter 05 real (0 10]
BT product of 3dB bandwidth and symbol time forGaussian filter
05 real (0 10]
dagger for each array element array size must be 7
Pin Inputs
Pin Name Description Signal Type
1 PSDU PSDU bits int
Pin Outputs
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Pin Name Description Signal Type
2 burst IEEE80211b burst with idle complex
3 BurstPreFilter IEEE80211b burst without idle complex
4 Header header bits int
5 PLCP PLCP bits int
NotesEquations
This model is used to generate a CCK baseband signal according to IEEE 80211b1Functions are implemented that are essential to an 11b baseband signal includingpreamble header and PSDU generation signal scrambling DBPSK and DQPSKmapping CCK modulation ramp time and idle time attaching pulse shaping isattached as the final block to reduce the transmitted bandwidth thereby increasingspectral efficiencyThe schematic for this subnetwork is shown in the following figure
WLAN_11bCCKSignalSrc1 Schematic
Rate is used to determine the transmitted data rate It can be chosen from the lists2of 55 Mbps and 11 MbpsPLCPType is used to select the format of the preambleheader sections of the framed3signal Long and Short can be selectedOctets indicates data bytes per burst (note that it is in bytes to transform it into4bits multiply by 8)ClocksBit enables users to toggle the clock locked flag in the header This is Bit 2 in5the Service field of the PPDU frame This bit is used to indicate to the receiver if thecarrier and the symbol clock use the same local oscillator and the designer can setthis bit If ClocksBit=Locked the clock bit is 1 (otherwise it is 0)The InitPhase parameter specifies the initial phase of the DBPSK signal The default6value is set to PI40ScramblerInit indicates the initial state of scrambler in WLAN 11b specification this7value is set to 1101100PwrType specifies the pattern for generating the ramp signal None Linear or8
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Cosine The Cosine ramp gives the least amount of out-of-channel interference Nonestarts transmitting the signal at full power (it is the simplest power ramp toimplement) and the Linear ramp shapes the burst in a linear fashionRampTime specifies the length (in microseconds) of the power updown ramp it is9used when PwrType is Linear or CosineOverSampling indicates the oversampling ratio of transmission signal For example if10OverSampling = Ratio_4 it means the transmission signal is upsampled with 4 timesThere are 8 kinds of oversampling ratios ranged from 2 to 9 to be supportedIdleInterval indicates the idle time added between two consecutive bursts which is in11[0 1000 microsec]FilterType specifies a baseband filter that is used to reduce the transmitted12bandwidth thereby increasing spectral efficiency The 80211b specification does notspecify what type of filter must be used but the transmitted signal must meet thespectral mask requirements FilterType options are
NoneFilter No transmitter filter is usedGaussian The Gaussian filter does not have zero ISI Wireless system architectsmust determine just how much of the inter-symbol interference can be toleratedin a system and combine that with noise and interference The Gaussian filter isGaussian-shaped in both the time and frequency domains it does not ring likethe root-cosine filters ring The effects of this filter in the time domain arerelatively short and each symbol interacts significantly (or causes ISI) with onlythe preceding and succeeding symbols This reduces the tendency for particularsequences of symbols to interact which makes amplifiers easier to build andmore efficientRoot-Cosine Root-cosine filters (also referred to as square root raised-cosinefilters) have the property that their impulse response rings at the symbol rateAdjacent symbols do not interfere with each other at the symbol times becausethe response equals zero at all symbol times except the center (desired) oneRoot-cosine filters heavily filter the signal without blurring the symbols togetherat the symbol times This is important for transmitting information withouterrors caused by ISI Note that ISI does exist at all times except at symbol(decision) timesIdeal-Lowpass In the frequency domain this filter appears as a lowpassrectangular filter with very steep cut-off characteristics The passband is set toequal the symbol rate of the signal Due to a finite number of coefficients thefilter has a predefined length and is not truly ideal The resulting ripple in thecut-off band is effectively minimized with a Hamming window A symbol lengthof 32 or greater is recommended for this filter
Taps is the filter length and determines how many symbol periods will be used in the13calculation of the symbol The filter selection influences the value of Taps
The Gaussian filter has a rapidly decaying impulse response so a filter length of6 is recommended greater lengths have negligible effects on the accuracy ofthe signalThe root-cosine filter has a slowly decaying impulse response A filter length ofapproximately 32 is recommended beyond this the ringing has negligibleeffects on the accuracy of the signalThe ideal lowpass filter also has a very slow decaying impulse response A filterlength of 32 or greater is recommendedFor both root-cosine and ideal lowpass filters the greater the filter length thegreater the accuracy of the signal
Alpha is to set the sharpness of a root-cosine filter when FilterType=Root-Cosine14BT is the Gaussian filter coefficient B is the 3 dB bandwidth of the filter and T is the15duration of the symbol period BT determines the extent of the filtering of the signalCommon values for BT are 03 to 05
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References
IEEE Standard 80211b-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer Extension in the24 GHz Band 1999
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WLAN_11bMuxBurst
Description 11b burst multiplexerLibrary WLAN 11b Signal SourceClass SDFWLAN_11bMuxBurst
Parameters
Name Description Default Unit Type Range
Rate data rate Mbps_1 Mbps_2 Mbps_55 Mbps_11 Mbps_55 enum
ModType modulation type CCK PBCC CCK enum
PLCPType PLCP preamble type Long Short Long enum
Octets octet number of PSDU 100 int (0 2312]
PwrType power on and off ramp type None LinearCosine
None enum
RampTime power on and off ramp time 20microsec sec real [0microsec1000microsec]
Pin Inputs
Pin Name Description Signal Type
1 PSDU PSDU complex
2 PLCP PLCP preamble and header complex
Pin Outputs
Pin Name Description Signal Type
3 Burst 11b burst signal complex
NotesEquations
This model multiplexes the PLCP including preamble and header and PSDU into a1signal burst This burst is the frame format time Two different preambles andheaders are defined
The mandatory supported long preamble and header illustrated in the followingfigure inter-operates with the current 1 Mbits and 2 Mbits DSSS specification(as described in the IEEE Standard 80211 1999 Edition)
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80211b Signal Burst with Long PLCP Preamble
The optional short preamble and header illustrated in the following figure isintended for applications where maximum throughput is desired and inter-operability with legacy and non-short-preamble capable equipment is not aconsideration That is it is expected to be used only in networks of likeequipment that can use the optional mode
80211b Signal Burst with Short PLCP Preamble
Transmit power-on and power-down ramps are implemented as illustrated in the2following figures The RampTime setting is used when PwrType is set to Linear orCosine
Transmit Power-On Ramp
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Transmit Power-Down Ramp
References
IEEE Standard 80211b-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer Extension in the24 GHz Band 1999IEEE Standard 80211-1999 Part 11 Wireless LAN Medium Access Control (MAC)2and Physical Layer (PHY) specifications 1999
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WLAN_11bPBCCSignalSrc
Description Signal source of IEEE 80211b with idle and PBCC modulationLibrary WLAN 11b Signal SourceClass SDFWLAN_11bPBCCSignalSrc
Parameters
Name Description Default Unit Type Range
Rate data rate Mbps_55 Mbps_11 Mbps_55 enum
PLCPType PLCP preamble type Long Short Long enum
Octets octet number of PSDU 100 int (0 2312]
ClocksBit locked clocks bit Not Locked Locked enum
InitPhase initial phase of DBPSK 0785 real [0 2π )
ScramblerInit initial state of scrambler 1 1 0 1 1 00
intarray
0 1dagger
PwrType power on and off ramp type None Linear Cosine None enum
RampTime power on and off ramp time 20microsec sec real [0microsec1000microsec]
OverSampling sampling rate of pulse-shaping filter Ratio_2 Ratio_3Ratio_4 Ratio_5 Ratio_6 Ratio_7 Ratio_8 Ratio_9
Ratio_2 enum
IdleInterval idle time 500microsec sec real [0microsec1000microsec]
FilterType pulse-shaping filter type NoneFilter Gaussian Root-Cosine Ideal-Lowpass
Root-Cosine
enum
Taps number of taps 6 int [1 1000]
Alpha roll-off factor for root raised-cosine filter 05 real (0 10]
BT product of 3dB bandwidth and symbol time forGaussian filter
05 real (0 10]
dagger for each array element array size must be 7
Pin Inputs
Pin Name Description Signal Type
1 PSDU PSDU bits int
Pin Outputs
Pin Name Description Signal Type
2 burst IEEE80211 burst complex
NotesEquations
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This model is used to generate a 55 or 11 Mbps DSSPBCC signal source according1to IEEE 80211b It performs PLCP preamble and header generation DBPSKDQPSKmodulation Barker spreading PBCC convolutional encoding multiplexing andshapingThe schematic is shown in the following figure
WLAN_11bPBCCSignalSrc Schematic
Rate is used to determine the transmitted data rate2PLCPType is used to select the format (Long or Short) of the preambleheader3sections of the framed signalOctets indicates data bytes per burst (note that it is in bytes to transform it into4bits multiply by 8)ClocksBit enables users to toggle the clock locked flag in the header This is Bit 2 in5the Service field of the PPDU frame it is used to indicate to the receiver if the carrierand the symbol clock use the same local oscillator and the designer can set this bitIf ClocksBit=Locked the clock bit is 1 (otherwise it is 0)InitPhase specifies the initial phase of the DBPSK signal The default value is set to6PI40ScramblerInit indicates the initial state of scrambler in WLAN 11b specification this7value is set to 1101100PwrType specifies the pattern for generating the ramp signal None Linear or8Cosine The Cosine ramp gives the least amount of out-of-channel interference Nonestarts transmitting the signal at full power (it is the simplest power ramp toimplement) and the Linear ramp shapes the burst in a linear fashionRampTime specifies the length (in microseconds) of the power updown ramp it is9used when PwrType is Linear or Cosine
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OverSampling indicates the oversampling ratio of transmission signal For example if10OverSampling = Ratio_4 it means the transmission signal is upsampled with 4 timesThere are 8 kinds of oversampling ratios ranged from 2 to 9 to be supportedIdleInterval indicates the idle time added between two consecutive bursts which is in11[0 1000 microsec]FilterType specifies a baseband filter to be applied to reduce the transmitted12bandwidth thereby increasing spectral efficiency The 80211b specification does notspecify what type of filter must be used but the transmitted signal must meet thespectral mask requirements FilterType options are
NoneFilter No transmitter filter is usedGaussian The Gaussian filter does not have zero ISI Wireless system architectsmust determine how much of the inter-symbol interference can be tolerated in asystem and combine that with noise and interference The Gaussian filter isGaussian-shaped in both the time and frequency domains it does not ring likeroot-cosine filters ring The effects of this filter in the time domain are relativelyshort and each symbol interacts significantly (or causes ISI) with only thepreceding and succeeding symbols This reduces the tendency for particularsequences of symbols to interact which makes amplifiers easier to build andmore efficientRoot-Cosine Root-cosine (also referred to as square root raised-cosine) filtershave the property that their impulse response rings at the symbol rate Adjacentsymbols do not interfere with each other at the symbol times because theresponse equals zero at all symbol times except the center (desired) one Root-cosine filters heavily filter the signal without blurring the symbols together atthe symbol times This is important for transmitting information without errorscaused by ISI Note that ISI exists at all times except at symbol (decision)timesIdeal-Lowpass In the frequency domain this filter appears as a lowpassrectangular filter with very steep cut-off characteristics The passband is set toequal the symbol rate of the signal Due to a finite number of coefficients thefilter has a predefined length and is not truly ideal The resulting ripple in thecut-off band is effectively minimized with a Hamming window A symbol lengthof 32 or greater is recommended for this filter
Taps is the filter length and determines how many symbol periods will be used in the13calculation of the symbol The filter selection influences the value of Taps
The Gaussian filter has a rapidly decaying impulse response so the filter lengthof 6 is recommended Greater lengths have negligible effects on the accuracy ofthe signalThe root-cosine filter has a slowly decaying impulse response A filter length ofapproximately 32 is recommended Beyond this the ringing has negligibleeffects on the accuracy of the signalThe ideal lowpass filter also has a very slow decaying impulse response A filterlength of 32 or greater is recommendedFor both root-cosine and ideal lowpass filters the greater the filter length thegreater the accuracy of the signal
Alpha specifies the sharpness of a root-cosine filter when FilterType=Root-Cosine14BT is the Gaussian filter coefficient B is the 3 dB bandwidth of the filter T is the15duration of the symbol period BT determines the extent of the filtering of the signalCommon values for BT are 03 to 05As illustrated in the following figures one PPDU frame includes PLCP Preamble PLCP16Header and PSDU
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Long PLCP PPDU Format
Short PLCP PPDU Format
References
IEEE Standard 80211b-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer Extension in the24 GHz Band 1999IEEE Standard 80211-1999 Part 11 Wireless LAN Medium Access Control (MAC)2and Physical Layer (PHY) specifications 1999
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WLAN_11bScrambler
Description 11b scramblerLibrary WLAN 11b Signal SourceClass SDFWLAN_11bScrambler
Parameters
Name Description Default Type Range
InitState initial state of scrambler 1 1 0 1 1 0 0 intarray
0 or 1array size is7
Octets octet number of PSDU 100 int (0 2336]
Pin Inputs
Pin Name Description Signal Type
1 input bits to be scrambled int
Pin Outputs
Pin Name Description Signal Type
2 output scrambled bits int
NotesEquations
This component scrambles all data bits transmitted Each firing when Octets bytes1are consumed and produced the scrambler is reset to its initial stateThe generator polynomial is G ( z ) = z -7 + z -4 + 1 The following figure illustrates2the scrambler
Data Scrambler
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The feed-through configuration of the scrambler and descrambler is self-synchronizing which requires no prior knowledge of the transmitter initialization ofthe scrambler for receiver processingThe scrambler also generates the PLCP SYNC field3For a long preamble the SYNC field consists of 128 bits of scrambled 1 bits Theinitial state of the scrambler (seed) is [1101100] where the left end bit specifies thevalue to place in the first delay element Z 1 and the right end bit specifies the valueto place in the last delay element Z 7For a short preamble the short SYNC field consists of 56 bits of scrambled 0 bits Theinitial state of the scrambler (seed) is [001 1011]
References
IEEE Standard 80211b-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer Extension in the24 GHz Band 1999
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WLAN_11SignalSrc
Description Signal source of IEEE 80211 with idleLibrary WLAN 11b Signal SourceClass SDFWLAN_11SignalSrc
Parameters
Name Description Default Unit Type Range
Rate data rate Mbps_1 Mbps_2 Mbps_1 enum
ModType modulation type CCK PBCC CCK enum
PLCPType PLCP preamble type Long Short Long enum
Octets octet number of PSDU 100 int (0 2312]
ClocksBit locked clocks bit Not Locked Locked enum
InitPhase initial phase of DBPSK 0785 real [0 2π )
ScramblerInit initial state of scrambler 1 1 0 1 10 0
intarray
0 1dagger
PwrType power on and off ramp type None Linear Cosine None enum
RampTime power on and off ramp time 20microsec sec real [0microsec1000microsec]
OverSampling sampling rate of pulse-shaping filter Ratio_2 Ratio_3Ratio_4 Ratio_5 Ratio_6 Ratio_7 Ratio_8 Ratio_9
Ratio_2 enum
IdleInterval idle time 500microsec sec real [0microsec1000microsec]
FilterType pulse-shaping filter type NoneFilter Gaussian Root-Cosine Ideal-Lowpass
Root-Cosine
enum
Taps number of taps 6 int [1 1000)
Alpha roll-off factor for root raised-cosine filter 05 real (0 10]
BT product of 3dB bandwidth and symbol time forGaussian filter
05 real (0 10]
dagger for each array element array size must be 7
Pin Inputs
Pin Name Description Signal Type
1 PSDU PSDU bits int
Pin Outputs
Pin Name Description Signal Type
2 burst IEEE 80211 burst complex
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NotesEquations
This subnetwork generates an HRDSSS and HRDSSSshort IEEE 80211b signal1source It performs PLCP preamble and header generation DBPSKDQPSKmodulation Barker spreading multiplexing and shapingThe schematic is shown in the following figure
WLAN_11SignalSrc Schematic
Rate is used to determine the transmitted data rate2PLCPType is used to select the format (Long or Short) of the preambleheader3sections of the framed signalOctets indicates data bytes per burst (note that it is in bytes to transform it into4bits multiply by 8)ClocksBit enables users to toggle the clock locked flag in the header This is Bit 2 in5the Service field of the PPDU frame it is used to indicate to the receiver if the carrierand the symbol clock use the same local oscillator and the designer can set this bitIf ClocksBit=Locked the clock bit is 1 (otherwise it is 0)InitPhase specifies the initial phase of the DBPSK signal6ScramblerInit indicates the initial state of scrambler in the WLAN 11b specification7this value is 1101100PwrType specifies the pattern for generating the ramp signal None Linear or8Cosine The Cosine ramp gives the least amount of out-of-channel interference Nonestarts transmitting the signal at full power (it is the simplest power ramp toimplement) and the Linear ramp shapes the burst in a linear fashionRampTime specifies the length (in microseconds) of the power updown ramp it is9used when PwrType is Linear or CosineOverSampling indicates the oversampling ratio of transmission signal For example if10OverSampling = Ratio_4 it means the transmission signal is upsampled with 4 timesIdleInterval indicates the idle time added between two consecutive bursts which is in11[0 1000 microsec]FilterType specifies which baseband filter is applied to reduce the transmitted12
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bandwidth thereby increasing spectral efficiency The 80211b specification does notspecify what type of filter must be used but the transmitted signal must meet thespectral mask requirements FilterType options are
NoneFilter No transmitter filter is usedGaussian The Gaussian filter does not have zero ISI Wireless system architectsmust determine just how much of the inter-symbol interference can be toleratedin a system and combine that with noise and interference The Gaussian filter isGaussian shaped in both the time and frequency domains and it does not ringlike the root-cosine filters do The effects of this filter in the time domain arerelatively short and each symbol interacts significantly (or causes ISI) with onlythe preceding and succeeding symbols This reduces the tendency for particularsequences of symbols to interact which makes amplifiers easier to build andmore efficientRoot-Cosine Root-cosine filters (also referred to as square root raised cosinefilters) have the property that their impulse response rings at the symbol rateAdjacent symbols do not interfere with each other at the symbol times becausethe response equals zero at all symbol times except the center (desired) oneRoot-cosine filters heavily filter the signal without blurring the symbols togetherat the symbol times This is important for transmitting information withouterrors caused by ISI Note that ISI exists at all times except at symbol(decision) timesIdeal-Lowpass In the frequency domain this filter appears as a lowpassrectangular filter with very steep cut-off characteristics The passband is set toequal the symbol rate of the signal Due to a finite number of coefficients thefilter has a predefined length and is not truly ideal The resulting ripple in thecut-off band is effectively minimized with a Hamming window A symbol lengthof 32 or greater is recommended for this filter
Taps is the filter length and determines how many symbol periods will be used in the13calculation of the symbol The filter selection influences the value of Taps
The Gaussian filter has a rapidly decaying impulse response so the filter lengthof 6 is recommended Greater lengths have negligible effects on the accuracy ofthe signalThe root-cosine filter has a slowly decaying impulse response A filter length ofapproximately 32 is recommended Beyond this the ringing has negligibleeffects on the accuracy of the signalThe ideal lowpass filter also has a very slow decaying impulse response A filterlength of 32 or greater is recommendedFor both root-cosine and ideal lowpass filters the greater the filter length thegreater the accuracy of the signal
Alpha is to set the sharpness of a root-cosine filter when FilterType=Root-Cosine14BT is the Gaussian filter coefficient The B is the 3 dB bandwidth of the filter and T is15the duration of the symbol period BT determines the extent of the filtering of thesignal Common values for BT are 03 to 05As illustrated in the following figures one PPDU frame includes PLCP Preamble PLCP16Header and PSDU
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Long PLCP PPDU Format
Short PLCP PPDU Format
References
IEEE Standard 80211b-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer Extension in the24 GHz Band 1999IEEE Standard 80211-1999 Part 11 Wireless LAN Medium Access Control (MAC)2and Physical Layer (PHY) specifications 1999
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WLAN_802_11bRF
Description WLAN 80211b signal sourceLibrary WLAN 11b Signal SourceClass TSDFWLAN_802_11bRFDerived From baseARFsource
Parameters
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Name Description Default Sym Unit Type Range
ROut Source resistance DefaultROut Ohm real (0 infin)
RTemp Temperature DefaultRTemp Celsius real [-27315infin)
TStep Expression showing how TStep isrelated to the other sourceparameters
111MHzOversamplingRatio
string
FCarrier Carrier frequencyCH1_24120M CH3_24220MCH5_24320M CH6_24370MCH7_24420M CH9_24520MCH11_24620M CH13_24720M
CH1_24120M Hz realenum
Power Power 004 W real [0 infin)
MirrorSpectrum Mirror spectrum about carrierNO YES
NO enum
GainImbalance Gain imbalance Q vs I 00 dB real (-infin infin)
PhaseImbalance Phase imbalance Q vs I 00 deg real (-infin infin)
I_OriginOffset I origin offset (percent) 00 real (-infin infin)
Q_OriginOffset Q origin offset (percent) 00 real (-infin infin)
IQ_Rotation IQ rotation 00 deg real (-infin infin)
OversamplingRatio Oversampling ratio 2 S int [2 9]
DataRate Data rate (Mbps) Mbps_1Mbps_2 Mbps_55 Mbps_11
Mbps_11 R enum
Modulation Modulation format CCK PBCC CCK enum
PreambleFormat Preambleheader format LongShort
Long H enum
ClkLockedFlag Lock header clock NO YES YES enum
PwrRamp RF power ramp shape NoneLinear Cosine
None P enum
IdleInterval Burst idle interval 100 microsec I sec real [01000microsec]
FilterType Shaping filter type NoneFilterGaussian Root Cosine IdealLowpass
Gaussian enum
RRC_Alpha RRC roll-off factor 02 real (00 10]
GaussianFilter_bT Gaussian filter bT coefficient 03 real (00 10]
FilterLength Filter length (chips) 6 int [1 200]
DataType Payload data type PN9 PN15FIX4 _4_1_4_0 _8_1_8_0_16_1_16_0 _32_1_32_0_64_1_64_0
PN9 enum
DataLength Data length (bytes per burst) 100 L int [1 2312]
Pin Outputs
Pin Name Description Signal Type
1 RF RF output timed
NotesEquations
This WLAN signal source generates an IEEE 80211b and 80211g DSSSCCKPBCC1RF signalTo use this source RF carrier frequency (FCarrier) and power (Power) must be set
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RF impairments can be introduced by setting the ROut RTemp MirrorSpectrumGainImbalance PhaseImbalance I_OriginOffset Q_OriginOffset and IQ_Rotationparameters80211bg signal characteristics an be specified by setting the OversamplingRatioDataRate Modulation PreambleFormat ClkLockedFlag PwrRamp IdleIntervalFilterType RRC_Alpha GaussianFilter_bT FilterLength DataType and DataLengthparametersThis signal source includes a DSP section RF modulator and RF output resistance as2illustrated in the following figure
Source Block Diagram
The ROut and RTemp parameters are used by the RF output resistance The FCarrierPower MirrorSpectrum GainImbalance PhaseImbalance I_OriginOffsetQ_OriginOffset and IQ_Rotation parameters are used by the RF modulator Theremaining signal source parameters are used by the DSP blockThe RF output from the signal source is at the frequency specified (FCarrier) with thespecified source resistance (ROut) and with power (Power) delivered into a matchedload of resistance ROut The RF signal has additive Gaussian noise power set by theresistor temperature (RTemp)This WLAN 80211b signal source model is compatible with the Agilent Signal Studio3Software for 80211 WLAN Agilent E4438C ESG Vector Signal Generator Option 417for transmitter testDetails regarding Signal Studio for WLAN 80211 are included at the websitehttpwwwagilentcomfindsignalstudio The 80211b baseband signal source frame structure is illustrated in the following4figures Each frame is separated by an IdleInterval one 80211b frame consists ofPLCP Preamble PLCP Header and Data (PSDU) parts (PPDU means physical layerprotocol data units SFD means start frame delimiter CRC means cyclic redundancycode PLCP means physical layer convergence procedure PSDU means PLCP servicedata units)
Long PLCP Frame Format
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Short PLCP Frame Format
Parameter Details5ROut is the RF output source resistanceRTemp is the RF output source resistance temperature in Celsius and sets thenoise density in the RF output signal to (k(RTemp+27315)) WattsHz where kis Boltzmanns constantFCarrier is the RF output signal frequencyPower is the RF output signal power The Power of the signal is defined as theaverage frame power and excludes the idle interval time intervalsMirrorSpectrum is used to mirror the RF_out signal spectrum about the carrierThis is equivalent to conjugating the complex RF envelope voltageDepending on the configuration and number of mixers in an RF transmitter theRF output signal from hardware RF generators can be inverted If such an RFsignal is desired set this parameter to YESGainImbalance PhaseImbalance I_OriginOffset Q_OriginOffset andIQ_Rotation are used to add certain impairments to the ideal output RF signalImpairments are added in the order described hereThe unimpaired RF I and Q envelope voltages have gain and phase imbalanceapplied The RF is given by
where A is a scaling factor based on Power and ROut parameters specified bythe designer V I( t ) is the in-phase RF envelope V Q( t ) is the quadraturephase RF envelope g is the gain imbalance
and φ (in degrees) is the phase imbalanceNext the signal V RF( t ) is rotated by IQ_Rotation degrees The I_OriginOffsetand Q_OriginOffset are then applied to the rotated signal Note that theamounts specified are percentages with respect to the output rms voltage Theoutput rms voltage is given by sqrt(2 times ROut times Power)OversamplingRatio sets the oversampling ratio of 80211b RF signal source
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Eight oversampling ratios (2 3 4 5 6 7 8 9) are supported by this source IfOversamplingRatio = 4 the simulation RF bandwidth is larger than the signalbandwidth by a factor of 4 (eg for Bandwidth=11 MHz the simulation RFbandwidth = 11 MHz times 4 = 44 MHz)DataRate specifies the data rate 1 2 55 and 11 Mbps can be implemented inthis source All data rates are defined in 80211b specificationModulation is defined as CCK or PBCC which are two modulation formats in80211b This parameter is useless for 1 Mbps and 2 Mbps data rates For 55Mbps and 11 Mbps data rates the two different modulation formats availableare CCK and PBCCPreambleFormat is used to set the format of the framed signal preambleheadersections refer to the previous figuresClkLockedFlag is used to toggle the clock locked flag in the header This is Bit 2in the Service field of the PPDU frame This bit is used to indicate to the receiverif the carrier and the symbol clock use the same local oscillator IfClkLockedFlag=YES this bit is set to 1 if ClkLockedFlag=NO this bit is set to 0PwrRamp is used to select shape of the RF burst in framed mode Select thepower updown ramp type Cosine ramp gives least amount of out-of-channelinterference None starts transmitting the signal at full power and is thesimplest power ramp to implement Linear ramp shapes the burst in a linearfashion The length (in microseconds) of the power updown ramp is set to 2microsec when PwrRamp is not NoneIdleInterval sets an idle duration time between two consecutive bursts whengenerating the 80211b signal sourceFilterType can be used to specify that a baseband filter is applied to reduce thetransmitted bandwidth thereby increasing spectral efficiency The 80211bspecification does not indicate the type of filter to be used but the transmittedsignal must meet the spectral mask requirements Four options for basebandfiltering are available
None (no filter)Gaussian The Gaussian filter does not have zero ISI Wireless systemarchitects must determine how much of the ISI can be tolerated in asystem and combine that with noise and interference The Gaussian filter isGaussian-shaped in time and frequency domains and it does not ring asroot cosine filters doThe effects of this filter in the time domain are relatively short and eachsymbol interacts significantly (or causes ISI) with only the preceding andsucceeding symbols This reduces the tendency for particular sequences ofsymbols to interact which makes amplifiers easier to build and moreefficientRoot Cosine (also referred to as square root raised-cosine) These filtershave the property that their impulse response rings at the symbol rateAdjacent symbols do not interfere with each other at the symbol timesbecause the response equals zero at all symbol times except the center(desired) oneRoot cosine filters heavily filter the signal without blurring the symbolstogether at the symbol times This is important for transmitting informationwithout errors caused by ISI Note that ISI exists at all times except at thesymbol (decision) timesIdeal Low Pass In the frequency domain this filter appears as a lowpassrectangular filter with very steep cut-off characteristics The passband isset to equal the symbol rate of the signal Due to a finite number ofcoefficients the filter has a predefined length and is not truly ideal Theresulting ripple in the cut-off band is effectively minimized with a Hamming
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window A symbol length of 32 or greater is recommended for this filterRRC_Alpha is used to set the sharpness of a root cosine filter whenFilterType=Root CosineGaussianFilter_bT is the Gaussian filter coefficient B is the 3 dB bandwidth ofthe filter T is the duration of the symbol period BT determines the extent ofthe filtering of the signal Common values for BT are 03 to 05FilterLength is used to set the number of symbol periods to be used in thecalculation of the symbolFor DataType
if PN9 is selected a 511-bit pseudo-random test pattern is generatedaccording to CCITT Recommendation O153if PN15 is selected a 32767-bit pseudo-random test pattern is generatedaccording to CCITT Recommendation O151if FIX4 is selected a zero-stream is generatedif x_1_x_0 is selected where x equals 4 8 16 32 or 64 a periodic bitstream is generated with the period being 2 x In one period the first xbits are 1s and the second x bits are 0s
DataLength is used to set the number of data bytes in a frame
References
IEEE Standard 80211b-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer Extension in the24 GHz Band 1999
httpstandardsieeeorggetieee802download80211b-1999pdfIEEE P80211gD82 Part 11 Wireless LAN Medium Access Control (MAC) and2Physical Layer (PHY) specifications Further Higher Data Rate Extension in the 24GHz Band April 2003
httpstandardsieeeorggetieee802download80211g-2003pdfCCITT Recommendation O151(1092)3CCITT Recommendation O153(1092)4
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WLAN_Barker
Description Barker spreaderLibrary WLAN 11b Signal SourceClass SDFWLAN_Barker
Pin Inputs
Pin Name Description Signal Type
1 input input signals to be spread complex
Pin Outputs
Pin Name Description Signal Type
2 output output signals afterspreading
complex
NotesEquations
This component spreads the input symbols1The 11-chip Barker sequence is used as the PN code sequence for the 1 and 2 Mbits2modulation
+1 -1 +1 +1 -1 +1 +1 +1 -1 -1 -1
The left-most chip is output first in time The first chip is aligned at the start of atransmitted symbol The symbol duration will be exactly 11 chips long
References
IEEE Standard 80211b-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer Extension in the24 GHz Band 1999
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WLAN_CCKMod
Description CCK modulatorLibrary WLAN 11b Signal SourceClass SDFWLAN_CCKMod
Parameters
Name Description Default Type Range
Rate data rate Mbps_55 Mbps_11 Mbps_11 enum
Octets octet number of PSDU 100 int (0 2312]
Pin Inputs
Pin Name Description Signal Type
1 input input bits to be CCKmodulated
int
2 InitialPhase initial phase complex
Pin Outputs
Pin Name Description Signal Type
3 output output signals after modulation and spreading complex
NotesEquations
This component is used as a CCK modulator1For CCK modulation modes the spreading code length is 8 and is based oncomplementary codes The chip rate is 11 Mchips The symbol duration is exactly 8complex chips The following formula is used to derive the CCK code words that areused for spreading 55 and 11 Mbits
where C is the code word C = c0 to c7φ1 φ2 φ3 and φ4 are defined differently for 55 Mbits and 11 MbitsThis formula creates 8 complex chips (c0 to c7) where c0 is transmitted first in timeThis is a form of the generalized Hadamard transform encoding where φ1is added to all code chips φ2 is added to all odd code chips φ φ3 is added to all oddpairs of code chips and φ4 is added to all odd quads of code chipsφ1 modifies the phase of all code chips of the sequence and is DQPSK encoded for55 and 11 Mbits This takes the form of rotating the whole symbol by theappropriate amount relative to the phase of the preceding symbol Note that chip c7of the symbol defined above is the chip that indicates the symbol phase and is
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transmitted lastCCK 55 Mbits ModulationAt 55 Mbits 4 bits (d0 to d3 d0 first in time) are transmitted per symbolData bits d0 and d1 encode φ1 based on DQPSK DQPSK encoding is given in thefollowing table ( j ω is defined as counterclockwise rotation) The phase change forφ1 is relative to the phase φ1 of the preceding symbol For the header to PSDUtransition the phase change for φ1 is relative to the phase of the preceding DQPSK(2 Mbits) symbol That is the phase of the last symbol of the CRC-16 is thereference phase for the first symbol generated from the PSDU octetsAll odd-numbered symbols generated from the PSDU octets are given an extra 180-degree rotation (in addition to the standard DQPSK modulation in the followingtable) The PSDU symbols are numbered starting with 0 for the first symbol todetermine odd and even symbols (that is the PSDU transmission starts on an even-numbered symbol)
DQPSK Encoding
Dibit pattern (d0 d1)(d0 is first in time)
Even symbolsphase change ( jω)
Odd symbolsphase change ( jω)
00 0 π
01 π2 3π2 (minusπ2)
11 π 0
10 3π2 (minusπ2) π2
Data dibits d2 and d3 CCK encode the basic symbol according to the following tablethat is derived from the above formula by setting φ2 = (d2 times π) + π2 φ3 = 0 andφ4 = (d3 times π) d2 and d3 are in the order shown and the complex chips are shownc0 to c7 (left to right) with c0 transmitted first in time
55Mbits CCK Encoding
d2 d3 c1 c2 c3 c4 c5 c6 c7 c8
00 1j 1j 1j -1j 1j 1j -1j 1j
01 -1j -1j -1j 1j 1j 1j -1j 1j
10 -1j 1j -1j -1j -1j 1j 1j 1j
11 1j -1j 1j 1j -1j 1j 1j 1j
CCK 11 Mbits ModulationAt 11 Mbits 8 bits (d0 to d7 d0 first in time) are transmitted per symbolThe first dibit (d0 d1) encodes φ1 based on DQPSK DQPSK encoding is given in thefollowing table The phase change for φ1 is relative to the phase φ1 of the precedingsymbol In the case of header to PSDU transition the phase change for φ1 is relativeto the phase of the preceding DQPSK symbol All odd-numbered symbols of the PSDUare given an extra 180-degree rotation in accordance with the DQPSK modulationshown in the following table Symbol numbering starts with 0 for the first symbol ofthe PSDUData dibits (d2 d3) (d4 d5) and (d6 d7) encode φ2 φ3 and φ4 respectivelybased on QPSK as given in the following tableNote that the following table is binary (not Grey) coded
QPSK Encoding
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Dibit pattern [did(i+1)](di is first in time)
Phase
00 0
01 π2
10 π
11 3π2(minusπ2)
References
IEEE Standard 80211b-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer Extension in the24 GHz Band 1999
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WLAN_CRC
Description CRC calculationLibrary WLAN 11b Signal SourceClass SDFWLAN_CRC
Pin Inputs
Pin Name Description Signal Type
1 input signal to be crc protected int
Pin Outputs
Pin Name Description Signal Type
2 output PLCP header int
NotesEquations
The SIGNAL SERVICE and LENGTH fields are protected with a CCITT CRC-16 frame1check sequence (FCS) The CCITT CRC-16 FCS is the ones complement of theremainder generated by the modulo 2 division of the protected PLCP fields by thepolynomial X 16 + X 12 + X 5 +1Protected bits are processed in transmit order and FCS calculations are made prior to2data scrambling as illustrated in the following figure
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CCITT CRC-16 Implementation
References
IEEE Standard 80211b-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer Extension in the24 GHz Band 1999IEEE Standard 80211-1999 Part 11 Wireless LAN Medium Access Control (MAC)2and Physical Layer (PHY) specifications 1999
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WLAN_HeaderMap
Description Header mapperLibrary WLAN 11b Signal SourceClass SDFWLAN_HeaderMap
Parameters
Name Description Default Type
PLCPType PLCP preamble type LongShort
Long enum
Pin Inputs
Pin Name Description Signal Type
1 input PLCP header signal int
2 inphase initial signal from preamble mapper complex
Pin Outputs
Pin Name Description Signal Type
3 next last complex mappingsignal
complex
4 output complex mapping signal complex
NotesEquations
This model outputs the PLCP header mapping signal and phase The long PLCP1preamble uses 1 Mbits DBPSK modulation the short PLCP preamble uses 2 MbitsDQPSK modulationThe initial phase of DBPSK or DQPSK signal is given by pin inphase2DBPSK encoding is given in the following table
DBPSK Encoding
Bit input Phase change (+jw)
0 0
1 π
DQPSK encoding is given in the following table
DQPSK Encoding
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Dibit pattern (d0d1) Phase change (+jw)
00 0
01 π2
11 π
10 3 times π2 (minusπ2)
References
IEEE Standard 80211b-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer Extension in the24 GHz Band 1999IEEE Standard 80211-1999 Part 11 Wireless LAN Medium Access Control (MAC)2and Physical Layer (PHY) specifications 1999
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WLAN_IdlePadding
Description idle paddingLibrary WLAN 11b Signal SourceClass SDFWLAN_IdlePadding
Parameters
Name Description Default Unit Type Range
Rate data rate Mbps_1 Mbps_2 Mbps_55 Mbps_11 Mbps_55 enum
ModType modulation type CCK PBCC CCK enum
PLCPType PLCP preamble type Long Short Long enum
Octets octet number of PSDU 100 int (0 2312]
RampTime power on and off ramp time 20usec sec real [0usec1000usec]
PwrType power on and off ramp type None Linear Cosine None enum
OverSampling sampling rate of pulse-shaping filter Ratio_2 Ratio_3Ratio_4 Ratio_5 Ratio_6 Ratio_7 Ratio_8 Ratio_9
Ratio_2 enum
IdleInterval idle time 500usec sec real [0usec1000usec]
Pin Inputs
Pin Name Description Signal Type
1 DataIn input data complex
Pin Outputs
Pin Name Description Signal Type
2 DataOut output data complex
NotesEquations
This model is used to append the idle time between the consecutive packet (PPDUs)1
References
IEEE Standard 80211b-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer Extension in the24 GHz Band 1999
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WLAN_MuxPLCP
Description PLCP multiplexerLibrary WLAN 11b Signal SourceClass SDFWLAN_MuxPLCP
Parameters
Name Description Default Type
PLCPType PLCP preamble type LongShort
Long enum
Pin Inputs
Pin Name Description Signal Type
1 header PLCP header complex
2 preamble PLCPpreamble
complex
Pin Outputs
Pin Name Description Signal Type
3 PLCP output PLCP complex
NotesEquations
This component is used to multiplex the PLCP preamble and header1Two different preambles and headers are defined2
The mandatory supported long preamble and header which is interoperable withthe current 1 Mbits and 2 Mbits DSSS specification (described in IEEEStandard 80211 1999 Edition) is illustrated in the following figure
Long PLCP PPDU Format
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An optional short preamble and header illustrated in the following figure
Short PLCP PPDU Format
The long PLCP preamble and header and short PLCP preamble use the 1 MbitsBarker code spreading with DBPSK modulation The short PLCP header uses the2 Mbits Barker code spreading with DQPSK modulation
References
IEEE Standard 80211b-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer Extension in the24 GHz Band 1999
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WLAN_PBCCConvCoder
Description PBCC convolutional encoderLibrary WLAN 11b Signal SourceClass SDFWLAN_PBCCConvCoder
Parameters
Name Description Default Type Range
Octets octet number of PSDU 100 int (0 2312]
Pin Inputs
Pin Name Description Signal Type
1 input signal to be convolutional coded int
Pin Outputs
Pin Name Description Signal Type
2 output signal after convolutional coded int
NotesEquations
This model implements a PBCC convolutional encoder with appending 1 octet zeros1The DSSSPBCC scheme uses a 64-state binary convolutional code (BCC) The outputof the BCC is encoded jointly onto the I and Q channelsA 64-state rate s binary convolutional code is used The generator matrix for the2code is given as
G = [ D 6 + D 4 + D 3 + D + 1 D 6 + D 5 + D 4 + D 3 + D 2 + 1]
in octal notation it is given by
G = [133 175]
The encoder block diagram the following figure consists of 6 memory elements Forevery data bit input 2 output bits are generated
PBCC Convolutional Encoder
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Since the system is frame (PPDU) based the encoder must be in state zero (ie all3memory elements contain zero at the beginning of each PPDU) The encoder mustalso be placed in a known state at the end of each PPDU to prevent the data bits nearthe end of the PPDU from being substantially less reliable than those early on in thePPDU To place the encoder in a known state at the end of a PPDU at least sixdeterministic bits must be input immediately following the last data bit input to theconvolutional encoder This is achieved by appending one octet containing all zeros tothe end of the PPDU prior to transmission and discarding the final octet of eachreceived PPDU In this manner the decoding process can be completed reliably onthe last data bits
References
IEEE Standard 80211b-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer Extension in the24 GHz Band 1999IEEE Standard 80211-1999 Part 11 Wireless LAN Medium Access Control (MAC)2and Physical Layer (PHY) specifications 1999
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WLAN_PBCCMod
Description PBCC modulatorLibrary WLAN 11b Signal SourceClass SDFWLAN_PBCCMod
Parameters
Name Description Default Type Range
Rate data rate Mbps_55 Mbps_11 Mbps_55 enum
Octets octet number of PSDU 100 int (0 2312]
Pin Inputs
Pin Name Description Signal Type
1 DataIn the output of the PBCC binary convolutionencoder
int
2 InitialPhase initial phase complex
Pin Outputs
Pin Name Description Signal Type
3 DataOut the output of the PBCCmodulator
complex
NotesEquations
This model is used to map the output of the PBCC binary convolution encoder to a1constellation using BPSK (for 55 Mbps) or QPSK (for 11 Mbps) modes
For 55 Mbps each firing one token is consumed at InitialPhaseint(Octets times 8 times 2 tokens are consumed at DataIn and the same number oftokens is produced at DataOutFor 11 Mbps each firing one token is consumed at InitialPhaseint(Octets) times 8 times 2 tokens are consumed at DataIn and int(Octets) times 8 tokensare produced at DataOut
PBCC modulation is illustrated in the following figure2
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PBCC Modulation
Mapping from BCC outputs to PSK constellation points in BPSK and QPSK modes that3are determined by a pseudo-random cover sequence illustrated in the followingfigure (For more details regarding the pseudo-random cover sequence refer to [1])
Cover Code Mapping
The InitialPhase input pin indicates the phase of the last chip of the PLCP header4(that is the last chip of the CRC check)
References
IEEE Standard 80211b-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer Extension in the24 GHz Band 1999
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WLAN_PLCPHeader
Description 11b PLCP Header without CRCLibrary WLAN 11b Signal SourceClass SDFWLAN_PLCPHeader
Parameters
Name Description Default Type Range
Rate data rate Mbps_1 Mbps_2 Mbps_55Mbps_11
Mbps_55 enum
ModType modulation type CCK PBCC CCK enum
ClocksBit locked clocks bit Not Locked Locked enum
Octets octet number of PSDU 100 int (0 2312]
Pin Outputs
Pin Name Description Signal Type
1 output PLCP header signal without CRC int
NotesEquations
This model outputs the PLCP header signal1The header format is illustrated in the following figure2
PLCP Header Format
The 8-bit SIGNAL field indicates to the PHY the modulation for PSDU transmissionand MPDU reception The data rate is equal to the SIGNAL field value multiplied by100 kbits The high rate PHY supports four mandatory rates given by 8-bit wordswhich represent the rate in units of 100 kbits where the lsb is transmitted in time
X0A (msb to lsb) for 1 MbitsX14 (msb to lsb) for 2 MbitsX37 (msb to lsb) for 55 MbitsX6E (msb to lsb) for 11 Mbits
Three bits are defined in the SERVICE field to support the high rate extension
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The right-most bit 7 supplements the LENGTH field described in thePLCP Length fieldBit 3 indicates the modulation method 0 = CCK 1 = PBCCBit 2 indicates that the transmit frequency and symbol clocks arederived from the same oscillator This locked clocks bit is set by thePHY layer configuration
The SERVICE field transmits b0 first in time and is protected by the CCITT CRC-16frame check sequence described in the PLCP CRC field An IEEE 80211-compliantdevice sets the values of bits b0 b1 b4 b5 and b6 to 0
b0 b1 b2 b3 b4 b5 b6 b7
Reserved Reserved Locked clocks bit 0= not1 = locked
Mod selectionbit0 = CCK1 = PBCC
Reserved Reserved Reserved Lengthextension bit
The PLCP length field 16-bit integer indicates the number of microseconds required totransmit the PSDU The transmitted value is determined by the Octets and RateparametersOctets is converted to microseconds for inclusion in the PLCP Length field The Lengthfield is calculated as follows Since there is an ambiguity in the number of octets thatis described by a length in integer microseconds for any data rate over 8 Mbits alength extension bit is placed at bit position b7 in the SERVICE field to indicate whenthe smaller potential number of octets is correct
55 Mbits CCK Length = number of octets times 8 55 rounded up tothe next integer11 Mbits CCK Length = number of octets times 8 11 rounded up tothe next integer the service field (b7) bit will indicate a 0 if roundingtook less than 811 or a 1 if rounding took more than or equal to 8 1155 Mbits PBCC Length = (number of octets + 1) times 8 55 roundedup to the next integer11 Mbits PBCC Length = (number of octets + 1) times 8 11 roundedup to the next integer the service field (b7) bit will indicate a 0 ifrounding took less than 811 or a 1 if rounding took more than orequal to 8 11
At the receiver the number of octets in the MPDU is calculated as follows
55 Mbits CCK Number of octets = Length times 55 8 rounded downto the next integer11 Mbits CCK Number of octets = Length times 11 8 rounded down tothe next integer minus 1 if the service field (b7) bit is a 155 Mbits PBCC Number of octets = (Length times 55 8) - 1 roundeddown to the next integer11 Mbits PBCC Number of octets = (Length times 11 8) - 1 roundeddown to the next integer minus 1 if the service field (b7) bit is a 1
At the transmitter LENGTH field and length extension bit values are calculated
LENGTHx = ((number of octets + P) times 8) RLENGTH = Ceiling (LENGTHx)
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If ((R == 11) ampamp ((LENGTH - LENGTHx) gt= 8 11))
then Length Extension = 1else Length Extension = 0At the receiver the number of octets in the MPDU is calculated
Number of octets = Floor (Length times R 8 - P - Length Extension)
where
R is the data rate in MbitsP = 0 for CCK 1 for PBCCCeiling (X) returns the smallest integer value greater than or equal to XFloor (X) returns the largest integer value less than or equal to X
The least significant bit (lsb) are transmitted first in time
References
IEEE Standard 80211b-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer Extension in the24 GHz Band 1999IEEE Standard 80211-1999 Part 11 Wireless LAN Medium Access Control (MAC)2and Physical Layer (PHY) specifications 1999
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WLAN_PLCPPreamble
Description 11b PLCP preambleLibrary WLAN 11b Signal SourceClass SDFWLAN_PLCPPreamble
Parameters
Name Description Default Type
PLCPType PLCP preamble type LongShort
Long enum
Pin Outputs
Pin Name Description Signal Type
1 output PLCP preamble signal int
NotesEquations
This model outputs the PLCP preamble signal according to the PLCPType parameter1When PLCPType is set to Long the long high rate PLCP preamble is output Theformat is illustrated in the following figure
Long PLCP Preamble Format
The SYNC field which consists of 128 bits of scrambled 1 bits is provided forreceiver synchronization The initial state of the scrambler (seed) is [1101100]where the left-most bit specifies the value for the first delay element Z 1 (see thefollowing figure) and the right-most bit specifies the value of the last delay elementin the scrambler
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Data Scrambler
The SFD indicates the start of PHY-dependent parameters within the PLCP preambleThe SFD is a 16-bit field [1111 0011 1010 0000] where the right-most bit istransmitted firstWhen PLCPType is set to Short the short high rate PLCP preamble (illustrated in thefollowing figure) is output
Short PLCP Preamble Format
The short SYNC field which consists of 56 bits of scrambled 0 bits is provided forreceiver synchronization The initial state of the scrambler (seed) is [001 1011]where the left end bit specifies the value for the first delay element Z 1 and the rightend bit specifies the value to put in the last delay element Z 7 The short SFD will be a 16-bit field and will be the time reverse of the field of the SFDin the long PLCP preamble The field is the bit pattern 0000 0101 1100 1111 Theright end bit will be transmitted first in time
References
IEEE Standard 80211b-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer Extension in the24 GHz Band 1999
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WLAN_PreambleMap
Description Preamble mapperLibrary WLAN 11b Signal SourceClass SDFWLAN_PreambleMap
Parameters
Name Description Default Type Range
PLCPType PLCP preamble type LongShort
Long enum
InitPhase initial phase of DBPSK 31416 4 real [0 2π )
Pin Inputs
Pin Name Description Signal Type
1 preamble PLCP preamble signal int
Pin Outputs
Pin Name Description Signal Type
2 next last DBPSK signal complex
3 output complex DBPSK signal complex
NotesEquations
This model outputs the PLCP preamble mapping signal and phase Both long PLCP1and short PLCP preambles use 1 Mbits DBPSK modulationThe InitPhase parameter specifies the initial phase of the DBPSK signal DBPSKencoding is given in the following table
DBPSK Encoding
Bit Input Phase Change (+jw)
0 0
1 π
References
IEEE Standard 80211b-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer Extension in the24 GHz Band 1999IEEE Standard 80211-1999 Part 11 Wireless LAN Medium Access Control (MAC)2and Physical Layer (PHY) specifications 1999
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WLAN_PSDUMap
Description PSDU mapperLibrary WLAN 11b Signal SourceClass SDFWLAN_PSDUMap
Parameters
Name Description Default Type Range
Rate data rate Mbps_1 Mbps_2 Mbps_1 enum
Octets octet number of PSDU 100 int (0 2312]
Pin Inputs
Pin Name Description Signal Type
1 PSDU PSDU signal int
2 inphase initial phase from headermapper
complex
Pin Outputs
Pin Name Description Signal Type
3 output complex mapping signal complex
NotesEquations
This model outputs a PSDU mapping signal The basic access rate is based on 11Mbits DBPSK modulation the enhanced access rate is based on 2 Mbits DQPSKmodulationDBPSK encoding is given in the following table
DBPSK Encoding
Bit input Phase change (+jw)
0 0
1 π
DQPSK encoding is given in the following table
DQPSK Encoding
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Dibit pattern (d0d1) Phase change (+jw)
00 0
01 π2
11 π
10 3 times π2 (minusπ2)
References
IEEE Standard 80211b-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer Extension in the24 GHz Band 1999IEEE Standard 80211-1999 Part 11 Wireless LAN Medium Access Control (MAC)2and Physical Layer (PHY) specifications 1999
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WLAN_TransFilter
Description Pulse-shaping FilterLibrary WLAN 11b Signal SourceClass SDFWLAN_TransFilter
Parameters
Name Description Default Unit Type Range
FilterType pulse-shaping filter type NoneFilter Gaussian Root-Cosine Ideal-Lowpass
Gaussian enum
Taps number of taps 6 int [1 1000]
Interpolation interpolation ratio 1 int [1 infin)
Decimation decimation ratio 1 int [1 infin)
Alpha roll-off factor for root raised-cosine filter 05 real (0 10]
BT product of 3dB bandwidth and symbol time for Gaussianfilter
05 real (0 10]
Rate data rate Mbps_1 Mbps_2 Mbps_55 Mbps_11 Mbps_55 enum
ModType modulation type CCK PBCC CCK enum
PLCPType PLCP preamble type Long Short Long enum
Octets octet number of PSDU 100 int (0 2312]
RampTime power on and off ramp time 20microsec sec real [0microsec1000microsec]
PwrType power on and off ramp type None Linear Cosine None enum
Pin Inputs
Pin Name Description Signal Type
1 DataIn input data complex
Pin Outputs
Pin Name Description Signal Type
2 DataOut output data complex
NotesEquations
This model is the modulation pulse-shaping filter Each firing data with ramp and1PPDU is input then interpolated filtered and decimated InterpolationDecimationdata points are then outputThe impulse response of the rectangle filter can be given by2
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where Ts is symbol intervalThe impulse response of Gaussian filter can be given by3
and
where BT is the BT parameter and Ts is the symbol intervalThe impulse response of raised-cosine rolloff filter can be given by4
where α is the Alpha parameter and Ts is the symbol intervalThe impulse response of root raised-cosine filter has the following relationship with5the raised-cosine filter
h ( n ) = h 1( n ) ƒ h 1( n )
where h(n) is the impulse response of raised filter and h1(n) is root-raisedThis filter efficiently implements rational sample rate changes When the Decimation6ratio is gt1 the filter behaves exactly as if it were followed by a DownSamplecomponent similarly when the Interpolation ratio is set the filter behaves as if itwere preceded by an UpSample component However the implementation is muchmore efficient than it would be using UpSample and DownSample Arbitrary sample-rate conversions by rational factors can be accomplished this wayFilterType specifies a baseband filter that is used to reduce the transmitted7bandwidth thereby increasing spectral efficiency The 80211b specification does notspecify what type of filter must be used but the transmitted signal must meet thespectral mask requirements FilterType options are
NoneFilter No transmitter filter is usedGaussian The Gaussian filter does not have zero ISI Wireless system architectsmust determine just how much of the inter-symbol interference can be toleratedin a system and combine that with noise and interference The Gaussian filter isGaussian-shaped in both the time and frequency domains it does not ring likethe root-cosine filters ring The effects of this filter in the time domain arerelatively short and each symbol interacts significantly (or causes ISI) with onlythe preceding and succeeding symbols This reduces the tendency for particularsequences of symbols to interact which makes amplifiers easier to build andmore efficientRoot-Cosine Root-cosine filters (also referred to as square root raised-cosinefilters) have the property that their impulse response rings at the symbol rateAdjacent symbols do not interfere with each other at the symbol times becausethe response equals zero at all symbol times except the center (desired) oneRoot-cosine filters heavily filter the signal without blurring the symbols together
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at the symbol times This is important for transmitting information withouterrors caused by ISI Note that ISI does exist at all times except at symbol(decision) timesIdeal-Lowpass In the frequency domain this filter appears as a lowpassrectangular filter with very steep cut-off characteristics The passband is set toequal the symbol rate of the signal Due to a finite number of coefficients thefilter has a predefined length and is not truly ideal The resulting ripple in thecut-off band is effectively minimized with a Hamming window A symbol lengthof 32 or greater is recommended for this filter
Taps is the filter length and determines how many symbol periods will be used in the8calculation of the symbol The filter selection influences the value of Taps
The Gaussian filter has a rapidly decaying impulse response so a filter length of6 is recommended greater lengths have negligible effects on the accuracy ofthe signalThe root-cosine filter has a slowly decaying impulse response A filter length ofapproximately 32 is recommended Beyond this the ringing has negligibleeffects on the accuracy of the signalThe ideal lowpass filter also has a very slow decaying impulse response A filterlength of 32 or greater is recommendedFor both root-cosine and ideal lowpass filters the greater the filter length thegreater the accuracy of the signal
Alpha is to set the sharpness of a root-cosine filter when FilterType=Root-Cosine9BT is the Gaussian filter coefficient B is the 3 dB bandwidth of the filter and T is the10duration of the symbol period BT determines the extent of the filtering of the signalCommon values for BT are 03 to 05Rate is used to determine the transmitted data rate11PLCPType is used to select the format (Long or Short) of the preambleheader12sections of the framed signalOctets indicates data bytes per burst (note that it is in bytes to transform it into13bits multiply by 8)RampTime specifies the length (in microseconds) of the power updown ramp it is14used when PwrType is Linear or CosinePwrType specifies the pattern for generating the ramp signal None Linear or15Cosine The Cosine ramp gives the least amount of out-of-channel interference Nonestarts transmitting the signal at full power (it is the simplest power ramp toimplement) and the Linear ramp shapes the burst in a linear fashion
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80211a Signal SourcesWLAN 802 11aRF (wlan)WLAN 80211a RF (wlan)WLAN 80211a RF WithPN (wlan)WLAN 80211aSignalSrc (wlan)WLAN 80211aSignalSrc1 (wlan)WLAN DATA (wlan)WLAN ExtrPSDU (wlan)WLAN LPreambleGen (wlan)WLAN PSDU (wlan)WLAN SIGNAL (wlan)WLAN SPreambleGen (wlan)WLAN Tail (wlan)
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WLAN_802_11aRF
Description WLAN 80211a signal sourceLibrary WLAN Signal SourceClass TSDFWLAN_802_11aRFDerived From baseARFsource
Parameters
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Name Description Default Sym Unit Type Range
ROut Source resistance DefaultROut Ohm real (0 infin)
RTemp Temperature DefaultRTemp Celsius real [-27315infin)
TStep Expression showing how TStep isrelated to the other sourceparameters
1Bandwidth2^OversamplingOption
string
FCarrier Carrier frequency CH1_24120MCH3_24220M CH5_24320MCH6_24370M CH7_24420MCH9_24520M CH11_24620MCH13_24720M CH36_51800MCH40_52000M CH44_52200MCH48_52400M CH52_52600MCH56_52800M CH60_53000MCH64_53200M CH149_57450MCH153_57650M CH157_57850MCH161_58050M
CH1_24120M Hz realenum
(0 infin)
Power Power 004 W real [0 infin)
MirrorSpectrum Mirror spectrum about carrier NOYES
NO enum
GainImbalance Gain imbalance Q vs I 00 dB real (-infin infin)
PhaseImbalance Phase imbalance Q vs I 00 deg real (-infin infin)
I_OriginOffset I origin offset (percent) 00 real (-infin infin)
Q_OriginOffset Q origin offset (percent) 00 real (-infin infin)
IQ_Rotation IQ rotation 00 deg real (-infin infin)
OversamplingOption
Oversampling ratio option Option 0for Ratio 1 Option 1 for Ratio 2Option 2 for Ratio 4 Option 3 forRatio 8 Option 4 for Ratio 16 Option5 for Ratio 32
Option 2 for Ratio 4 S enum
DataRate Data rate (Mbps) Mbps_6 Mbps_9Mbps_12 Mbps_18 Mbps_24Mbps_27 Mbps_36 Mbps_48Mbps_54
Mbps_54 R enum
Bandwidth Bandwidth 20 MHz B Hz real (0 infin)
IdleInterval Burst idle interval 40 microsec I sec real [01000microsec]
DataType Payload data type PN9 PN15 FIX4_4_1_4_0 _8_1_8_0 _16_1_16_0_32_1_32_0 _64_1_64_0
PN9 enum
DataLength Data length (bytes per burst) 100 L int [1 4095]
GuardInterval Guard interval (frac FFT size) 025 real [0 1]
Pin Outputs
Pin Name Description Signal Type
1 RF RF output timed
NotesEquations
This WLAN signal source generates an IEEE 80211a and 80211g OFDM RF signal1To use this source the designer must set (as a minimum) RF carrier frequency(FCarrier) and power (Power)RF impairments can be introduced by setting the ROut RTemp MirrorSpectrum
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GainImbalance PhaseImbalance I_OriginOffset Q_OriginOffset and IQ_Rotationparameters80211ag signal characteristics can be specified by setting the OversamplingOptionDataRate Bandwidth IdleInterval DataType DataLength and GuardIntervalparameters
NoteWhile WLAN_802_11a_RF generates the same 11a RF signal format as WLAN_80211aRF theirparameters are not the same
This signal source includes a DSP section RF modulator and RF output resistance as2illustrated in the following figure
Signal Source Block Diagram
The ROut and RTemp parameters are used by the RF output resistance The FCarrierPower MirrorSpectrum GainImbalance PhaseImbalance I_OriginOffsetQ_OriginOffset and IQ_Rotation parameters are used by the RF modulator Theremaining signal source parameters are used by the DSP blockThe RF output from the signal source is at the frequency specified (FCarrier) with thespecified source resistance (ROut) and with power (Power) delivered into a matchedload of resistance ROut The RF signal has additive Gaussian noise power set by theresistor temperature (RTemp)This WLAN 80211a signal source model is compatible with the Agilent Signal Studio3Software for 80211 WLAN Agilent E4438C ESG Vector Signal Generator Option 417for transmitter testDetails regarding Signal Studio for WLAN 80211 are included at the website httpwwwagilentcomfindsignalstudio]Regarding the WLAN 80211ag signal burst structure one burst consists of four4parts Each burst is separated by an IdleInterval and is composed of the ShortPreamble Long Preamble SIGNAL and DATA fields
The Short Preamble field consists of 10 short preambles (8 microsec)The Long Preamble field consists of 2 long preambles (8 microsec) The twopreamble fields combined compose the PLCP Preamble that has a constant timeduration (16 microsec) for all source parameter settingsThe SIGNAL field includes 80211ag bursts of information (such as data ratepayload data and length)The DATA field contains the payload dataChannel coding interleaving mapping and IFFT processes are also included inSIGNAL and DATA parts generation The SIGNAL field and each individual Datafield (part of the overall DATA field) have a time duration defined as theOFDM_SymbolTime and includes a GuardInterval OFDM _SymbolTime dependson the Bandwidth (=64Bandwidth)The burst structure is illustrated in the following figures In these figures PLCPmeans physical layer convergence procedure PSDU means PLCP service dataunits GI means guard interval GI is set to 025 and Bandwidth is set to 20MHz (resulting in OFDM_SymbolTime = 4 microsec)
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80211ag Burst Format
OFDM Training Structure
Parameter Details5ROut is the RF output source resistanceRTemp is the RF output source resistance temperature in Celsius and sets thenoise density in the RF output signal to (k(RTemp+27315)) WattsHz where kis Boltzmanns constantFCarrier is the RF output signal frequencyPower is the RF output signal power The Power of the signal is defined as theaverage burst power and excludes the idle interval time intervalsMirrorSpectrum is used to mirror the RF_out signal spectrum about the carrierThis is equivalent to conjugating the complex RF envelope voltageDepending on the configuration and number of mixers in an RF transmitter theRF output signal from hardware RF generators can be inverted If such an RFsignal is desired set this parameter to YESGainImbalance PhaseImbalance I_OriginOffset Q_OriginOffset andIQ_Rotation are used to add certain impairments to the ideal output RF signalImpairments are added in the order described hereThe unimpaired RF I and Q envelope voltages have gain and phase imbalanceapplied The RF is given by
where A is a scaling factor based on the Power and ROut parameters specifiedby the designer V I( t ) is the in-phase RF envelope V Q( t ) is the quadraturephase RF envelope g is the gain imbalance
and φ (in degrees) is the phase imbalanceNext the signal V RF( t ) is rotated by IQ_Rotation degrees The I_OriginOffset
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and Q_OriginOffset are then applied to the rotated signal Note that theamounts specified are percentages with respect to the output rms voltage Theoutput rms voltage is given by sqrt(2 times ROut times Power)Bandwidth is used to determine the actual bandwidth of WLAN system and alsois used to calculate the sampling rate and time step per sample The defaultvalue is 20 MHz which is defined in 80211ag specification Bandwidth can beset to 40 MHz in order to double the rate for the 80211ag turbo modeOversamplingOption sets the oversampling ratio of 80211ag RF signal sourceOptions from 0 to 5 result in oversampling ratio 2 4 8 16 32 whereoversampling ratio = 2 OversamplingOption If OversamplingOption = 2 theoversampling ratio = 2 2 = 4 and the simulation RF bandwidth is larger than thesignal bandwidth by a factor of 4 (eg for Bandwidth=20 MHz the simulation RFbandwidth = 20 MHz times 4 = 80 MHz)DataRate specifies the data rate 6 9 12 18 24 27 36 48 and 54 Mbps areavailable in this source All data rates except 27 Mbps are defined in the80211ag specification 27 Mbps is from HIPERLAN2 [2]The following table lists key parameters of 80211ag
Rate-Dependent Values
Data Rate(Mbps)
Modulation CodingRate (R)
Coded Bits perSubcarrier(NBPSC)
Coded Bits perOFDM Symbol(NCBPS)
Data Bits perOFDM Symbol(NDBPS)
6 BPSK 12 1 48 24
9 BPSK 34 1 48 36
12 QPSK 12 2 96 48
18 QPSK 34 2 96 72
24 16-QAM 12 4 192 96
27 16-QAM 916 4 192 108
36 16-QAM 34 4 192 144
48 64-QAM 23 6 288 192
54 64-QAM 34 6 288 216
IdleInterval specifies the idle interval between two consecutive bursts whengenerating a 80211a signal sourceFor DataTypeif PN9 is selected a 511-bit pseudo-random test pattern is generated accordingto CCITT Recommendation O153if PN15 is selected a 32767-bit pseudo-random test pattern is generatedaccording to CCITT Recommendation O151if FIX4 is selected a zero-stream is generatedif x_1_x_0 is selected (where x equals 4 8 16 32 or 64) a periodic bit streamis generated with the period being 2 x In one period the first x bits are 1s andthe second x bits are 0sDataLength is used to set the number of data bytes in a frame (or burst) Thereare 8 bits per byteGuardInterval is used to set cyclic prefix in an OFDM symbol The value range ofGuardInterval is [0010] The cyclic prefix is a fractional ratio of the IFFTlength 80211ag defines GuardInterval=14 (08 microsec) and HIPERLAN2defines two GuardIntervals (18 and 14)
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References
IEEE Standard 80211a-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer in the 5 GHzBand 1999
httpstandardsieeeorggetieee802download80211a-1999pdfETSI TS 101 475 v111 Broadband Radio Access Networks (BRAN) HIPERLAN Type22 Physical (PHY) layer November 2000IEEE P80211G-2003 Part II Wireless LAN Medium Access Control (MAC) and3Physical Layer (PHY) specifications Amendment 4 Further Higher Data RateExtension in the 24 GHz Band April 2003
httpstandardsieeeorggetieee802download80211g-2003pdfCCITT Recommendation O151(1092)4CCITT Recommendation O153(1092)5
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WLAN_80211a_RF
Description Signal source of IEEE 80211a with RF modulationLibrary WLAN Signal SourceClass TSDFWLAN_80211a_RFDerived From WLAN_SignalSourceBase
Parameters
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Name Description Default Unit Type Range
ROut output resistance DefaultROut Ohm real (0 infin)
FCarrier carrier frequency 5200MHz Hz real (0 infin)
Power modulator output power 40mW W real (0 infin)
VRef reference voltage for output power calibration 01122V V real (0 infin)
Bandwidth bandwidth 20MHz Hz real (0 infin)
PhasePolarity if set to Invert Q channel signal is inverted NormalInvert
Normal enum
GainImbalance gain imbalance in dB Q channel relative to I channel 00 real (-infin infin)
PhaseImbalance phase imbalance in degrees Q channel relative to Ichannel
00 real (-infin infin)
I_OriginOffset I origin offset in percent with respect to output rmsvoltage
00 real (-infin infin)
Q_OriginOffset Q origin offset in percent with respect to output rmsvoltage
00 real (-infin infin)
IQ_Rotation IQ rotation in degrees 00 real (-infin infin)
NDensity noise spectral density at output in dBmHz -173975 real (-infin infin)
Length octet number of PSDU 256 int [1 4095]
Rate data rate Mbps_6 Mbps_9 Mbps_12 Mbps_18Mbps_24 Mbps_27 Mbps_36 Mbps_48 Mbps_54
Mbps_6 enum
Order FFT points=2^Order 6 int [6 11]
ScramblerInit initial state of scrambler 1 0 1 1 1 01
intarray
0 1dagger
Idle padded number of zeros between two bursts 0 int [0 infin)
WindowType type of window Specification CosRolloff Specification enum
TransitionTime the transition time of window function 100nsec sec real (0800nsec]
GuardType type of guard interval T2 T4 T8 T16 T32UserDefined
T4 enum
GuardInterval guard interval defined by user 16 int [0 2 Order]
dagger for each array element array size must be 7
Pin Outputs
Pin Name Description Signal Type
1 RF_Signal RF signals timed
2 For_EVM mapped SIGNAL and DATA complex
3 EncodedBits DATA before mapping int
4 PSDU PSDU bits int
5 SIGNAL SIGNAL int
NotesEquations
This WLAN signal source generates an IEEE 80211a and 80211g OFDM RF signal1The generated signal can be configured in a top-level design using modelparametersThe schematic for this subnetwork is shown in the following figure
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WLAN_80211a_RF Schematic
Model TkIQrms and TkPower are used to calibrate the output power When these are2activated and simulated the result shown in input IQ signal rms value should bethe VRef for WLAN_80211a_RF If VRef is set correctly the output power is thedesignated Power as can be seen in the Modulator output power in dBmOutputs include RF_Signal which is the timed signal after RF modulation For_EVM3signal which is used for EVM measurement EncodedBits which is encoded data bitsbefore interleaving PSDU which is the PSDU bits and SIGNAL which is the SIGNALbitsRegarding the WLAN 80211ag signal burst structure one burst consists of four4parts PLCP Preamble consists of 10 short preambles (8 usec) and 2 long preambles(8 usec) SIGNAL includes 80211ag bursts of information (such as data ratepayload data and length) DATA transmits payload data Channel codinginterleaving mapping and IFFT processes are also included in SIGNAL and DATAparts generation The burst structure is illustrated in 80211ag Burst Format andOFDM Training Structure The schematic of baseband 80211ag signal source isshown in WLAN_80211aSignalSrc1 Schematic
80211ag Burst Format
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OFDM Training Structure
WLAN_80211aSignalSrc1 Schematic
Parameter Details5The FCarrier parameter is the RF output signal frequencyThe Power parameter is the RF output signal powerThe PhasePolarity parameter is used to mirror the RF_Signal signal spectrumabout the carrier This is equivalent to conjugating the complex RF envelopevoltageDepending on the configuration and number of mixers in an RF transmitter theRF output signal from hardware RF generators can be inverted If such an RFsignal is desired set this parameter to Invert
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The GainImbalance PhaseImbalance I_OriginOffset Q_OriginOffset andIQ_Rotation parameters are used to add certain impairments to the ideal outputRF signal Impairments are added in the order described hereThe unimpaired RF I and Q envelope voltages have gain and phase imbalanceapplied The RF is given by
where A is a scaling factor based on the Power and R parameters specified bythe designer V I( t ) is the in-phase RF envelope V Q( t ) is the quadraturephase RF envelope g is the gain imbalance
and φ (in degrees) is the phase imbalanceNext the signal V RF( t ) is rotated by IQ_Rotation degrees The I_OriginOffsetand Q_OriginOffset are then applied to the rotated signal Note that theamounts specified are percentages with respect to the output rms voltage Theoutput rms voltage is given by sqrt(2 times R times Power)Bandwidth is used to determine the actual bandwidth of WLAN system and alsois used to calculate the sampling rate and time step per sample The defaultvalue is 20 MHz which is defined in 80211ag specification Bandwidth can beset to 40 MHz in order to double the rate for the 80211ag turbo modeOrder is set to the FFT size of OFDM symbol In fact this parameter controls theoversampling ratio of 80211ag RF signal source Oversampling ratios is 1 2 48 16 and 32 when Order is set to 6 7 8 9 10 and 11 respectivelyRate specifies the data rate 6 9 12 18 24 27 36 48 and 54 Mbps areavailable in this source All data rates except 27 Mbps are defined in the80211ag specification 27 Mbps is from HIPERLAN2The Idle parameter specifies padded number of zeros between two consecutivebursts when generating a 80211a signal source The duration of idle interval isIdleBandwidthLength is used to set the number of data bytes in a frame (or burst)GuardType is used to set cyclic prefix mode in an OFDM symbol Five modes aredefined T2 T8 T16 T32 and UserDefined The number of cyclic prefixsamples (GuardInterval parameter set it as GI in equations) is defined asif GuardType=T32 GI = 2 Order-5
if GuardType=T16 GI = 2 Order-4
if GuardType=T8 GI = 2 Order-3
if GuardType=T4 GI = 2 Order-2
if GuardType=T2 GI = 2 Order-1
if GuardType=UserDefined the number of cyclic prefix samples (GI) isdetermined by GuardIntervalGuardInterval is used to set length of cyclic prefix in an OFDM symbol ifGuardType=UserDefined
References
IEEE Standard 80211a-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer in the 5 GHzBand 1999IEEE P80211gD82 Part 11 Wireless LAN Medium Access Control (MAC) and2
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Physical Layer (PHY) specifications Further Higher Data Rate Extension in the 24GHz Band April 2003ETSI TS 101 475 v121 Broadband Radio Access Networks (BRAN) HIPERLAN Type32 Physical (PHY) layer November 2000
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WLAN_80211a_RF_WithPN
Description Signal source of IEEE 80211a with RF modulation and phase noiseLibrary WLAN Signal SourceClass TSDFWLAN_80211a_RF_WithPNDerived From WLAN_SignalSourceBase
Parameters
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Name Description Default Unit Type Range
RIn input resistance DefaultRIn Ohm real (0 infin)
ROut output resistance DefaultROut Ohm real (0 infin)
RTemp physical temperature in degrees C DefaultRTemp Ohm real [-27315infin)
Power modulator output power 40mW W real (0 infin)
VRef reference voltage for output power calibration 01122V V real (0 infin)
Bandwidth bandwidth 20MHz Hz real (0 infin)
GainImbalance gain imbalance in dB Q channel relative to I channel 00 real (-infin infin)
PhaseImbalance phase imbalance in degrees Q channel relative to Ichannel
00 real (-infin infin)
Frequency1 first RF tone frequency 5200MHz Hz real (0 infin)
Power1 first RF tone carrier power 001W W real (0 infin)
Phase1 first RF tone carrier phase in degrees 00 W real (-infin infin)
AdditionalTones list of additional RF tones defined with triple valuesfor frequency in Hz power in watts phase indegrees
00 realarray
(0 infin)
RandomPhase set phase of RF tones to random uniformlydistributed value between -PI and +PI No Yes NoYes
No enum
PhaseNoiseData phase noise specification defined with pairs of valuesfor offset frequency in Hz signal sideband pnasenoise level in dBc
00 realarray
(-infin infin)
PN_Type Phase noise model type with random or fixed offsetfreq spacing and amplitude Random PN Fixed freqoffset Fixed freq offset and amplitude Random PNFixed freq offset Fixed freq offset and amplitude
Random PN enum
Length octet number of PSDU 256 int [1 4095]
Rate data rate Mbps_6 Mbps_9 Mbps_12 Mbps_18Mbps_24 Mbps_27 Mbps_36 Mbps_48 Mbps_54
Mbps_6 enum
Order FFT points=2^Order 6 int [6 11]
ScramblerInit initial state of scrambler 1 0 1 1 1 0 1 intarray
0 1dagger
Idle padded number of zeros between two bursts 0 int [0 infin)
WindowType type of window Specification CosRolloff Specification enum
TransitionTime the transition time of window function 100nsec sec real (0800nsec]
GuardType type of guard interval T2 T4 T8 T16 T32UserDefined
T4 enum
GuardInterval guard interval defined by user 16 int [0 2Order ]
dagger for each array element array size must be 7
Pin Outputs
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Pin Name Description Signal Type
1 RF_Signal RF signals timed
2 For_EVM mapped SIGNAL and DATA complex
3 EncodedBits DATA before mapping int
4 PSDU PSDU bits int
5 SIGNAL SIGNAL int
NotesEquations
WLAN_80211a_RF_WithPN generates a WLAN transmission signal with phase noise1The generated signal can be configured in a top-level design using modelparametersThe schematic for this subnetwork is shown inthe following figure
WLAN_80211a_RF_WithPN Schematic
The IEEE 80211a baseband signal is fed into the RF modulator and phase noise is2introduced by N_TonesModel TkIQrms and TkPower are used to calibrate the output power When these are3activated and simulated the result shown in input IQ signal rms value should bethe VRef for WLAN_80211a_RF_WithPN If VRef is set correctly the output power isthe designated Power as can be seen in the Modulator output power in dBmThe power density spectrum of an oscillator signal with phase noise is modeled by a4Lorentzian spectrum The single-sided spectrum S s (f) is given by
The following figure illustrates a Lorentzian phase noise spectrum with a single-sidedminus3 dB line width of the oscillator signal N_Tones models phase noise based on theLorentzian spectrum
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Phase Noise Power Spectral Density
Outputs include RF_Signal (timed signal after RF modulation) For_EVM signal (used5for EVM measurement) EncodedBits (encoded data bits before interleaving) PSDU(PSDU bits) and SIGNAL (the SIGNAL bits)WLAN_80211aSignalSrc1 implements the baseband signal source functions according6to IEEE 80211a Standard including SIGNAL and DATA generation scramblingconvolutional coding interleaving mapping IFFT multiplexing adding a windowfunction and inserting idle The schematic is shown inthe following figure
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WLAN_80211aSignalSrc1 Schematic
Parameter Details7The Power parameter is the RF output signal powerThe GainImbalance PhaseImbalance parameters are used to add certainimpairments to the ideal output RF signal Impairments are added in the orderdescribed hereThe unimpaired RF I and Q envelope voltages have gain and phase imbalanceapplied The RF is given by
where A is a scaling factor based on the Power and R parameters specified bythe designer V I( t ) is the in-phase RF envelope V Q( t ) is the quadraturephase RF envelope g is the gain imbalance
and φ (in degrees) is the phase imbalanceNote that the amounts specified are percentages with respect to the output rmsvoltage The output rms voltage is given by sqrt(2 times R times Power)Bandwidth is used to determine the actual bandwidth of WLAN system and alsois used to calculate the sampling rate and time step per sample The defaultvalue is 20MHz which is defined in 80211ag specification Bandwidth can beset to 40 MHz in order to double the rate for the 80211ag turbo modeOrder is set to the FFT size of OFDM symbol In fact this parameter controls theoversampling ratio of 80211ag RF signal source Oversampling ratios is 1 2 48 16 and 32 when Order is set to 6 7 8 9 10 and 11 respectivelyRate specifies the data rate 6 9 12 18 24 27 36 48 and 54 Mbps areavailable in this source All data rates except 27 Mbps are defined in the80211ag specification 27 Mbps is from HIPERLAN2The Idle parameter specifies padded number of zeros between two consecutivebursts when generating a 80211a signal source The duration of idle interval isIdleBandwidthLength is used to set the number of data bytes in a frame (or burst)GuardType is used to set cyclic prefix mode in an OFDM symbol Five modes aredefined T2 T8 T16 T32 and UserDefined The number of cyclic prefixsamples (GuardInterval parameter set it as GI in equations) is defined asif GuardType=T32 GI = 2 Order-5
if GuardType=T16 GI = 2 Order-4
if GuardType=T8 GI = 2 Order-3
if GuardType=T4 GI = 2 Order-2
if GuardType=T2 GI = 2 Order-1
if GuardType=UserDefined the number of cyclic prefix samples (GI) isdetermined by GuardIntervalGuardInterval is used to set length of cyclic prefix in an OFDM symbol ifGuardType=UserDefined
References
IEEE Standard 80211a-1999 Part 11 Wireless LAN Medium Access Control (MAC)1
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and Physical Layer (PHY) specifications High-speed Physical Layer in the 5 GHzBand 1999IEEE P80211gD82 Part 11 Wireless LAN Medium Access Control (MAC) and2Physical Layer (PHY) specifications Further Higher Data Rate Extension in the 24GHz Band April 2003ETSI TS 101 475 v121 Broadband Radio Access Networks (BRAN) HIPERLAN Type32 Physical (PHY) layer November 2000
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WLAN_80211aSignalSrc
Description Signal source of IEEE 80211a with idleLibrary WLAN Signal SourceClass SDFWLAN_80211aSignalSrc
Parameters
Name Description Default Unit Type Range
Length octet number of PSDU 256 int [1 4095]
Rate data rate Mbps_6 Mbps_9 Mbps_12 Mbps_18Mbps_24 Mbps_27 Mbps_36 Mbps_48 Mbps_54
Mbps_6 enum
Order FFT points=2^Order 6 int [6 11]
ScramblerInit initial state of scrambler 1 0 1 1 1 01
intarray
0 1dagger
Idle padded number of zeros between two bursts 0 int [0 infin)
WindowType type of window Specification CosRolloff Specification enum
TransitionTime the transition time of window function 100nsec sec real [0800nsec]
GuardType type of guard interval T2 T4 T8 T16 T32UserDefined
T4 enum
GuardInterval guard interval defined by user 16 int [0 2 Order]
dagger for each array element array size must be 7
Pin Inputs
Pin Name Description Signal Type
1 PSDU PSDU bits int
Pin Outputs
Pin Name Description Signal Type
2 burst IEEE80211a burst complex
3 output mapping signal before IFFT complex
NotesEquations
This subnetwork performs IEEE 80211a DATA convolutional coding interleaving1mapping IFFT multiplexing and adds a window The schematic is shown in thefollowing figure
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WLAN_80211aSignalSrc Schematic
As illustrated in the following figure one PPDU frame includes PLCP Preamble (122symbols 10 short and 2 long preamble symbols) SIGNAL (one OFDM symbol) andDATA (variable number of OFDM symbols)Mapping modes are dependent on the Rate parameter in DATA and BPSK in SIGNALAfter mapping DATA and SIGNAL are multiplexed pilots are inserted IFFT isperformed PLCP preambles are multiplexed into one PPDU frame (or burst) and thewindow function is added
PPDU Frame Structure
References
IEEE Standard 80211a-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer in the 5 GHzBand 1999
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WLAN_80211aSignalSrc1
Description Signal source of IEEE 80211a with idleLibrary WLAN Signal SourceClass SDFWLAN_80211aSignalSrc1
Parameters
Name Description Default Unit Type Range
Length octet number of PSDU 256 int [1 4095]
Rate data rate Mbps_6 Mbps_9 Mbps_12 Mbps_18Mbps_24 Mbps_27 Mbps_36 Mbps_48 Mbps_54
Mbps_6 enum
Order FFT points=2^Order 6 int [6 11]
ScramblerInit initial state of scrambler 1 0 1 1 1 01
intarray
0 1dagger
Idle padded number of zeros between two bursts 0 int [0 infin)
WindowType type of window Specification CosRolloff Specification enum
TransitionTime the transition time of window function 100nsec sec real [0800nsec]
GuardType type of guard interval T2 T4 T8 T16 T32UserDefined
T4 enum
GuardInterval guard interval defined by user 16 int [0 2 Order]
dagger for each array element array size must be 7
Pin Inputs
Pin Name Description Signal Type
1 PSDU PSDU bits int
Pin Outputs
Pin Name Description Signal Type
2 burst IEEE80211a burst complex
3 For_EVM mapping signal before IFFT complex
4 EncodedBits DATA bits before mapping int
5 SIGNAL SIGNAL bits int
NotesEquations
This subnetwork performs IEEE 80211a DATA convolutional coding interleaving1mapping IFFT and multiplexing and adds a window function The schematic isshown in the following figure
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Mapping modes are dependent on the Rate parameter in DATA and BPSK in SIGNALAfter mapping DATA and SIGNAL are multiplexed pilots are inserted IFFT isperformed PLCP preambles are multiplexed into one PPDU frame (or burst) and awindow function is added
WLAN_80211aSignalSrc1 Schematic
One PPDU frame as illustrated in the following figure includes PLCP Preamble (102short and 2 long preamble symbols) SIGNAL (one OFDM symbol) and DATA (variablenumber of OFDM symbols)
PPDU Frame Structure
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References
IEEE Standard 80211a-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer in the 5 GHzBand 1999
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WLAN_DATA
Description DATA field of PPDULibrary WLAN Signal SourceClass SDFWLAN_DATA
Parameters
Name Description Default Type Range
Length octet number of PSDU 100 int [14095]
Rate data rate Mbps_6 Mbps_9 Mbps_12 Mbps_18 Mbps_24 Mbps_27Mbps_36 Mbps_48 Mbps_54
Mbps_6 enum
Pin Inputs
Pin Name Description Signal Type
1 PSDU PSDU bits int
Pin Outputs
Pin Name Description Signal Type
2 output DATA bits output int
NotesEquations
This model is used to generate data field of PPDU frame As illustrated in the1following figure the data field contains the service field the PSDU the tail bits andthe pad bits if needed All bits in the data field are scrambled
PPDU Frame Format
The service field (illustrated in the following figure) has 16 bits bit 0 is transmitted2first in time Bits 0 to 6 are set to zero and used to synchronize the descrambler inthe receiver The remaining bits (7 to 15) reserved for future use are set to zero
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SERVICE Field Bit Assignments
The PPDU tail bit field is 6 bits of 0 which are required to return the convolutional3encoder to the zero state This improves the error probability of the convolutionaldecoder which relies on future bits when decoding and which may be not beavailable past the end of the message The PLCP tail bit field is produced by replacing6 scrambled 0 bits following the end of message with 6 unscrambled 0 bitsThe number of bits in the data field is a multiple of N CBPS the number of coded bits4
in an OFDM symbol (48 96 192 or 288 bits) To achieve that the length of themessage is extended so that it becomes a multiple of N DBPS the number of data bits
per OFDM symbol At least 6 bits are appended to the message in order toaccommodate the tail bits The number of OFDM symbols N SYM the number of bits
in the data field N DATA and the number of pad bits N PAD are calculated from the
length of the PSDU (LENGTH) as follows
N SYM = Ceiling ((16 + 8 times LENGTH + 6) N DBPS )
N DATA = N SYM times N DBPS
N PAD = N DATA - (16 + 8 times LENGTH + 6)
The function ceiling () is a function that returns the smallest integer value greaterthan or equal to its argument value The appended bits ( pad bits ) are set to zerosand subsequently scrambled with the rest of the bits in the data fieldN CBPS and N DBPS are Rate dependent parameters listed in the following table
Rate-Dependent Values
Data Rate(Mbps)
Modulation CodingRate (R)
Coded Bits perSubcarrier(NBPSC)
Coded Bits perOFDM Symbol(NCBPS)
Data Bits perOFDM Symbol(NDBPS)
6 BPSK 12 1 48 24
9 BPSK 34 1 48 36
12 QPSK 12 2 96 48
18 QPSK 34 2 96 72
24 16-QAM 12 4 192 96
27 16-QAM 916 4 192 108
36 16-QAM 34 4 192 144
48 64-QAM 23 6 288 192
54 64-QAM 34 6 288 216
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References
IEEE Standard 80211a-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer in the 5 GHzBand 1999
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WLAN_ExtrPSDU
Description Extract PSDU from DATALibrary WLAN Signal SourceClass SDFWLAN_ExtrPSDU
Parameters
Name Description Default Type Range
Length octet number of PSDU 100 int [14095]
Rate data rate Mbps_6 Mbps_9 Mbps_12 Mbps_18 Mbps_24 Mbps_27Mbps_36 Mbps_48 Mbps_54
Mbps_6 enum
Pin Inputs
Pin Name Description Signal Type
1 DATA DATA bits int
Pin Outputs
Pin Name Description Signal Type
2 PSDU PSDU bits int
NotesEquations
This model is used to extract PSDU field from data bits Refer to the following figure1
PPDU Frame Format
References
IEEE Standard 80211a-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer in the 5 GHz
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Band 1999
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WLAN_LPreambleGen
Description Long training sequence generatorLibrary WLAN Signal SourceClass SDFWLAN_LPreambleGen
Pin Outputs
Pin Name Description Signal Type
1 output 52 long training sequences complex
NotesEquations
This model is used to generate the long training sequence in order to obtain the long1OFDM training symbol This symbol consists of 52 subcarriers which are modulatedby the elements of sequence L given by
L 051 = 1 1 -1 -1 1 1 -1 1 -1 1 1 1 1 1 1 -1 -1 1 1 -1 1 -1
1 1 1 1 1 -1 -1 1 1 -1 1 -1 1 -1 -1 -1 -1 -1 1 1 -1 -1 1 -11 -1 1 1 1 1
References
IEEE Standard 80211a-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer in the 5 GHzBand 1999ETSI TS 101 475 v111 Broadband Radio Access Networks (BRAN) HIPERLAN Type22 Physical (PHY) layer April 2000
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WLAN_PSDU
Description Source of coderLibrary WLAN Signal SourceClass SDFWLAN_PSDU
Pin Outputs
Pin Name Description Signal Type
1 output source signal int
NotesEquations
This model is used to generate 100 octets of PSDU data according to the following1table
PSDU
Value Value Value Value Value
15 04 02 00 2e 00
610 60 08 cd 37 a6
1115 00 20 d6 01 3c
1620 f1 00 60 08 ad
2125 3b af 00 00 4a
2630 6f 79 2c 20 62
3135 72 69 67 68 74
3640 20 73 70 61 72
4145 6b 20 6f 66 20
4650 64 69 76 69 6e
5155 69 74 79 2c 0a
5660 44 61 75 67 68
6165 74 65 72 20 6f
6670 66 20 45 6c 79
7175 73 69 75 6d 2c
7680 0a 46 69 72 65
8185 2d 69 6e 73 69
8690 72 65 64 20 77
9195 65 20 74 72 65
96100 61 da 57 99 ed
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References
IEEE Standard 80211a-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer in the 5 GHzBand 1999
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WLAN_SIGNAL
Description SIGNAL field of PPDULibrary WLAN Signal SourceClass SDFWLAN_SIGNAL
Parameters
Name Description Default Type Range
Length octet number of PSDU 100 int [14095]
Rate data rate Mbps_6 Mbps_9 Mbps_12 Mbps_18 Mbps_24 Mbps_27Mbps_36 Mbps_48 Mbps_54
Mbps_6 enum
Pin Outputs
Pin Name Description Signal Type
1 output SIGNAL bitsoutput
int
NotesEquations
The model is used to generate SIGNAL field of PPDU frame which is composed of 241bits as illustrated in the following figure Bits 0 to 3 encode the rate bit 4 isreserved for future use bits 5 to 16 encode the length field of the TXVECTOR withthe least significant bit (LSB) being transmitted first bit 17 is the positive (even)parity bit for bits 0 to 16 bits 18 to 23 constitute the signal tail field and are all setto zero
Signal Field Bit Assignments
The rate field conveys information about the type of modulation and the coding rate2as used in the rest of the packet Bits R1 to R4 are set dependent on Rate accordingto the values in the following table
Contents of Rate Field
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Rate (Mbps) R1 to R4
6 1101
9 1111
12 0101
18 0111
24 1001
27 1010
36 1011
48 0001
54 0011
The length field is an unsigned 12-bit integer that indicates the number of octets in3the PSDU that the MAC is currently requesting the physical layer to transmit Thetransmitted value will be in the 1 to 4095 range the LSB will be transmitted firstEncoding of the single SIGNAL OFDM symbol will be performed with BPSK modulation4of the subcarriers and using convolutional coding at R = 12 The encodingprocedure which includes convolutional encoding interleaving modulation mappingprocesses pilot insertion and OFDM modulation is as used for transmission of dataat a 6 Mbps rate Contents of the SIGNAL field are not scrambled
References
IEEE Standard 80211a-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer in the 5 GHzBand 1999
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WLAN_SPreambleGen
Description Short training sequence generatorLibrary WLAN Signal SourceClass SDFWLAN_SPreambleGen
Parameters
Name Description Default Type
ShortType type of short training sequence AB
B enum
Pin Outputs
Pin Name Description Signal Type
1 output 52 short trainingsequences
complex
NotesEquations
This model is used to generate the short training sequence in order to obtain the1short OFDM training symbol this symbol consists of 12 subcarriers that aremodulated by the elements of sequence S
If ShortType=B the short training sequences used for IEEE 80211a andHIPERLAN2 standards are
= middot 0 0 1+j 0 0 0 -1-j 0 0 0 1+j 0 0 0 -1-j 0 0 0 -1-j 0 0 0 1+j 00 0 0 0 0 -1-j 0 0 0 -1-j 0 0 0 1+j 0 0 0 1+j 0 0 0 1+j 0 0 01+j 00If ShortType=A the short training sequences used only for HIPERLAN2standards are
= middot 0 0 00-1+j 0 0 0 1+j 0 0 0 1-j 0 0 0 -1-j 0 0 0 -1+j0 0 0 -1-j 0 0 -1+j 0 0 0 -1-j 0 0 0-1+j 0 0 0 -1-j 0 0 0 1-j 0 00 1+j 0000
The multiplication factor normalizes the average power of the resultingOFDM symbol which uses 12 out of 52 subcarriers
References
IEEE Standard 80211a-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer in the 5 GHzBand 1999
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ETSI TS 101 475 v111 Broadband Radio Access Networks (BRAN) HIPERLAN Type22 Physical (PHY) layer April 2000
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WLAN_Tail
Description Attach tail bitsLibrary WLAN Signal SourceClass SDFWLAN_Tail
Parameters
Name Description Default Type Range
Length octet number of PSDU 100 int [14095]
Rate data rate Mbps_6 Mbps_9 Mbps_12 Mbps_18 Mbps_24 Mbps_27Mbps_36 Mbps_48 Mbps_54
Mbps_6 enum
Pin Inputs
Pin Name Description Signal Type
1 input DATA without zero tail bits int
Pin Outputs
Pin Name Description Signal Type
2 output DATA with six nonscrambled zerotailbits
int
NotesEquations
This model is used to add six 0 tail bits to the scrambled DATA field of PPDU The1position of tail bits is illustrated in the following figure
PPDU Frame Format
References
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IEEE Standard 80211a-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer in the 5 GHzBand 1999
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About WLAN Design Library
The Agilent EEsof WLAN Design Library is for the 5 and 24 GHz wireless LAN market IEEE80211a in the Americas MMAC in Japan BRAN HIPERLAN2 in Europe IEEE 80211b andIEEE 80211g This design library focuses on the physical layer of WLAN systems and isintended to be a baseline system for designers to get an idea of what a nominal or idealsystem performance would be Evaluations can be made regarding degraded systemperformance due to system impairments that may include nonideal componentperformance
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Agilent Instrument CompatibilityThis WLAN design library is compatible with Agilent E443xB ESG-D Series Digital RF SignalGenerator and Agilent E4438C ESG Vector Signal Generator
Also this WLAN design library is compatible with Agilent 89600 Series Vector SignalAnalyzer
The following table shows more information of instrument models Firmware revisions andoptions
Agilent Instrument Compatibility Information
WLAN DesignLibrary
ESG Models VSA Models
SpecVersion=1999 E443xB Firmware Revision B0375Option 410 - 80211a SoftwarePersonality (Signal Studio)E4438C Firmware Revision C0220Option 410 - 80211a SoftwarePersonality (Signal Studio)
89600 Series software version 301Option B7R - 80211a and HIPERLAN2OFDM Modulation Analysis
For more information about Agilent ESG Series of Digital and Analog RF Signal Generatorand Options please visit
httpwwwagilentcomfindESG
For more information about Agilent 89600 Series Vector Signal Analyzer and Optionsplease visit
httpwwwagilentcomfind89600
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WLAN SystemsThree wireless LAN standards IEEE 80211 ETSI BRAN HIPERLAN2 and MMAC HISWAN are being developed IEEE 80211 was initiated in 1990 and several draftstandards have been published for review including IEEE 80211 and IEEE 80211b for 24GHz with 55 and 11 Mbps The scope of the standard is to develop a MAC and physicallayer specification for wireless connectivity for fixed portable and moving stations within alocal area
In July 1998 the IEEE 80211 standardization group selected OFDM as the basis for anew physical layer standard (IEEE 80211a) This new physical layer standard has beenfinalized and targets 6 Mbps to 54 Mbps data rates in a 5 GHz band A common MACmechanism has been specified for IEEE 80211 IEEE 80211a and IEEE 80211b TheMAC mechanism provides CSMACA
The HIPERLAN2 standard is being developed in the ETSIBRAN project The system canoperate globally in a 5 GHz band Core specifications of the HIPERLAN2 standard werefinalized at the end of 1999 HIPERLAN2 provides high-speed 6 Mbps to 54 Mbps wirelessmultimedia communications between mobile terminals and various broadband corenetworks
The physical layer of HIPERLAN2 was harmonized with IEEE 80211a Orthogonalfrequency division multiplexing (OFDM) was selected as the modulation scheme thecodingmodulation scheme for the subcarriers of OFDM symbol is the same as that in IEEE80211a In support of QoS HIPERLAN2 adopts a centralized and scheduled MACmechanism
The HISWAN standard is being developed by ARIB the Japanese Multimedia Mobile AccessCommunication group The physical layer of HISWAN is the same as IEEE 80211a
All three 5 GHz WLAN standards have physical layers based on OFDM OFDM transmitsdata simultaneously over multiple parallel frequency sub-bands and offers robustperformance under severe radio channel conditions OFDM also offers a convenientmethod for mitigating delay spread effects A cyclic extension of the transmitted OFDMsymbol can be used to achieve a guard interval between symbols Provided that this guardinterval exceeds the excess delay spread of the radio channel the effect of the delayspread is constrained to frequency selective fading of the individual sub-bands This fadingcan be canceled by means of a channel compensator which takes the form of a single tapequalizer on each sub-band
The IEEE 80211a transmitter and receiver OFDM physical layer block diagram is shown inthe following figure
Major specifications for the IEEE 80211a OFDM physical layer are listed in the followingtable
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IEEE 80211a Transmitter and Receiver for OFDM Physical Layer Block Diagram
IEEE 80211a OFDM Physical Layer Major Specifications
Specification Settings
Information data rate 6 9 12 18 24 36 48 and 54 Mbps
Modulation BPSK OFDM QPSK OFDM 16-QAM OFDM 64-QAM OFDM
Error correcting code K = 7 (64 states) convolutional code
Coding rate 12 23 34
Number of subcarriers 52
OFDM symbolduration
40 micros
Guard interval 08 micros ( )
Occupied bandwidth 166 MHz
The HIPERLAN2 transmitter is shown in the following figure
Major specifications for the HIPERLAN2 OFDM physical layer are listed in the followingtable
HIPERLAN2 Transmitter for OFDM Physical Layer Block Diagram
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HIPERLAN2 Transmitter for OFDM Physical Layer Block Diagram
HIPERLAN2 OFDM Physical Layer Major Specifications
Specification Settings
Information data rate 6 9 12 18 24 27 36 and 54 Mbps
Modulation BPSK OFDM QPSK OFDM 16-QAM OFDM and 64-QAM OFDM
Error correcting code K = 7 (64 states) convolutional code
Coding rate 12 34 916
Number of subcarriers 52
Sampling rate 20 MHz
Useful symbol part duration 32 us
Cyclic prefix duration 08 us (mandatory) 04 us (mandatory)
Symbol interval 40 us ( )
36 us ( )
Sub-carrier spacing 03125 MHz ( )
Spacing between the two outmost sub-carriers 1625 MHz
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Component LibrariesThe WLAN Design Library is organized by library according to the types of behavioralmodels and subnetworks
11b Receivers
This library provides models for use with IEEE 80211b receivers
WLAN_11bBurstRec 11b burst receiverWLAN_11bBurstSync 11b burst synchronizerWLAN_11bCIREstimator channel estimator for 80211bWLAN_11bDFE decision feedback equalizer for 11bWLAN_11bDemuxBurst 11b burst demultiplexer and frequency compensatorWLAN_11bDescrambler 11b descramblerWLAN_11bFreqEstimator 11b frequency offset estimatorWLAN_11bPreamble signal source of IEEE 80211b preambleWLAN_11bRake rake combiner for 80211bWLAN_11b_Equalizer 80211b receiver with equalizerWLAN_11b_Rake 80211b Rake receiverWLAN_CCKDemod 11b CCK demodulatorWLAN_CCK_RF_Rx_DFE 80211b CCK receiver with equalizerWLAN_CCK_RF_Rx_Rake 80211b CCK Rake receiverWLAN_CCK_Rx_DFE 80211b CCK receiver with equalizerWLAN_CCK_Rx_Rake 80211b CCK Rake receiverWLAN_Despreader barker despreader for 11bWLAN_FcCompensator carrier frequency compensation for 80211bWLAN_HeaderDemap header demapperWLAN_PhaseRotator phase rotator after decision feedback equalizer for 11bWLAN_PrmblDemap preamble demapperWLAN_RecFilter receiver matched filter
11b Signal Sources
This library provides IEEE 80211b signal source generator All models can only be usedwith IEEE 80211b
WLAN_11SignalSrc signal source of IEEE 80211 with idleWLAN_11bCCKSignalSrc signal source of IEEE 80211b with idle and CCKmodulationWLAN_11bCCKSignalSrc1 signal source of IEEE 80211b with idle and CCKmodulationWLAN_11bCCK_RF RF Signal source of IEEE 80211b with idle and CCK modulationWLAN_11bMuxBurst IEEE 80211b burst multiplexerWLAN_11bPBCCSignalSrc signal source of IEEE 80211b with idle and PBCCmodulationWLAN_11bScrambler IEEE 80211b scramblerWLAN_Barker barker spreader
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WLAN_CCKMod CCK modulatorWLAN_CRC CRC calculationWLAN_HeaderMap header mapperWLAN_IdlePadding idle paddingWLAN_MuxPLCP PLCP multiplexerWLAN_PBCCConvCoder PBCC convolutional encoderWLAN_PBCCMod PBCC modulatorWLAN_PLCPHeader IEEE 80211b PLCP header without CRCWLAN_PLCPPreamble IEEE 80211b PLCP preambleWLAN_PSDUMap PSDU mapperWLAN_PreambleMap preamble mapperWLAN_TransFilter pulse-shaping filter
Channel Components
This library provides the WLAN channel model
WLAN_ChannelModel WLAN channel model
Channel Coding Components
This library provides models for channel coding scrambling and interleaving in thetransmitter end and channel decoding and deinterleaving in the receiving end All modelscan be used with IEEE 80211a and HIPERLAN2 systems
WLAN_11aConvDecoder 11a viterbi decoderWLAN_ConvCoder convolutional coding of input bitsWLAN_ConvDecoder bit-by-bit viterbi decoder for WLAN convolutional code (for IEEE80211a HIPERLAN2 and MMAC systems)WLAN_ConvDecoder1_2 convolutional decoder for 12 rateWLAN_Deinterleaver deinterleaving of input bitsWLAN_Interleaver interleave input bitsWLAN_PuncCoder puncture coderWLAN_PuncCoderP1 puncture coder pattern P1 for HIPERLAN2 systemsWLAN_PuncConvCoder punctured convolutional encoderWLAN_PuncConvDecoder punctured convolutional decoderWLAN_PuncDecoder puncture decoderWLAN_PuncDecoder1 punctured convolutional decoder (for IEEE 80211aHIPERLAN2 and MMAC systems)WLAN_PuncDecoderP1 puncture decoder pattern P1 for HIPERLAN2 systemsWLAN_Scrambler scramble the input bits
Measurements
This library provides models for BERPER EVM and constellation measurements for IEEE80211a systems
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WLAN_80211a_BERPER Bit and packet error rate measurements sinkWLAN_80211a_Constellation Constellation measurement sinkWLAN_80211a_EVM 80211a EVM measurementWLAN_80211a_RF_EVM EVM model for WLAN EVM MeasurementWLAN_DSSS_CCK_PBCC_EVM EVM measurement for DSSSCCKPBCC WLAN signals(80211b and non-OFDM 80211g)
Modulation Components
OFDM subcarriers are modulated using BPSK QPSK 16-QAM or 64-QAM modulation Thislibrary provides models for BPSK QPSK 16-QAM or 64-QAM modulation anddemodulation for IEEE 80211a HIPERLAN2 and MMAC systems
WLAN_BPSKCoder BPSK mappingWLAN_BPSKDecoder BPSK demappingWLAN_Demapper BPSK QPSK 16-QAM or 64-QAM demapping according to datarateWLAN_Mapper BPSK QPSK 16-QAM or 64-QAM mapping according to data rateWLAN_QAM16Coder 16-QAM mappingWLAN_QAM16Decoder 16-QAM demappingWLAN_QAM64Coder 64-QAM mappingWLAN_QAM64Decoder 64-QAM demappingWLAN_QPSKCoder QPSK mappingWLAN_QPSKDecoder QPSK demappingWLAN_SoftDemapper 11a soft demapper
Multiplex Components
This library provides models for IEEE 80211a and HIPERLAN2 systems
WLAN_BurstOut real burst outputWLAN_BurstReceiver burst receiverWLAN_CommCtrl2 2-input commutator with input particle number controlWLAN_CommCtrl3 3-input commutator with input particle number controlWLAN_CosRollWin cosine-rolloff window functionWLAN_DemuxBurst burst demultiplexer with frequency offset compensator andguard interval removerWLAN_DemuxBurstNF burst demultiplexer with guard interval remover withoutfrequency offset compensatorWLAN_DemuxOFDMSym OFDM signal demultiplexerWLAN_DemuxSigData signal and data signal demultiplexerWLAN_DistCtrl2 2-output distributor with output particle number controlWLAN_DistCtrl3 3-output distributor with output particle number controlWLAN_H2CosRollWin adds cosine-rolloff windows to burst signals for HIPERLAN2WLAN_H2MuxOFDMSym OFDM symbol multiplexer for HIPERLAN2WLAN_InsertZero insert zeros before data with input particle number controlWLAN_LoadIFFTBuff data stream loader into IFFT bufferWLAN_MuxBrdBurst broadcast burst multiplexer for HIPERLAN2WLAN_MuxBurst burst multiplexerWLAN_MuxBurstNW burst multiplexer without window function
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WLAN_MuxDLBurst downlink burst multiplexer for HIPERLAN2WLAN_MuxDataChEst data and estimated channel impulse response multiplexerWLAN_MuxDiBurst direct link burst multiplexer for HIPERLAN2WLAN_MuxOFDMSym OFDM symbol multiplexerWLAN_MuxSigData signal and data multiplexerWLAN_MuxULBurstL uplink burst with long preamble multiplexer for HIPERLAN2WLAN_MuxULBurstS uplink burst with short preamble multiplexer for HIPERLAN2
Receivers
This library provides models for use with IEEE 80211a receivers
WLAN_80211aRxFSync IEEE 80211a receiver with full frequency synchronizationfunctionWLAN_80211aRxFSync1 IEEE 80211a receiver with full frequency synchronizationfunctionWLAN_80211aRxNoFSync IEEE 80211a receiver without full frequencysynchronization functionWLAN_80211aRxNoFSync1 IEEE 80211a receiver without full frequencysynchronization functionWLAN_80211aRx_Soft IEEE 80211a receiver with full frequency synchronizationWLAN_80211a_RF_RxFSync IEEE 80211a receiver with full frequencysynchronizationWLAN_80211a_RF_RxNoFSync IEEE 80211a receiver without frequencysynchronizationWLAN_80211a_RF_Rx_Soft IEEE 80211a receiver with full frequencysynchronizationWLAN_BurstSync burst synchronizerWLAN_ChEstimator channel estimatorWLAN_FineFreqSync fine carrier frequency synchronizerWLAN_FreqSync carrier frequency synchronizerWLAN_OFDMEqualizer OFDM equalizer by the channel estimationWLAN_PhaseEst phase estimatorWLAN_PhaseTrack phase tracker in OFDM demodulationWLAN_RmvNullCarrier null sub-carrier remover in OFDM
Signal Sources
This library provides short and long training sequence generators and signal and data bitsgenerators All models can be used with IEEE 80211a and HIPERLAN2 systems
WLAN_80211aSignalSrc IEEE 80211a signal sourceWLAN_80211aSignalSrc1 IEEE 80211a signal source with idleWLAN_80211a_RF IEEE 80211a signal source with RF modulationWLAN_80211a_RF_WithPN IEEE 80211a signal source with RF modulation andphase noiseWLAN_DATA data part of PPDUWLAN_ExtrPSDU extract PSDU from dataWLAN_LPreambleGen long training sequence generator
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WLAN_PSDU source of coderWLAN_SIGNAL signal part of PPDUWLAN_SPreambleGen short training sequence generatorWLAN_Tail attach tail bits
Test Components
This library provides auxiliary models for basic measurements
WLAN_BERPER bit and packet error rate measurementsWLAN_EVM error vector magnitudeWLAN_RF_CCDF RF signal complementary cumulative distribution functionWLAN_RF_PowMeas power level measurement
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Glossary of Terms
ACPR adjacent channel power ratio
ARIB Association of Radio Industries and Business
BPSK binary phase shift keying
BRAN broadband radio access network
CIR channel impulse response
CSMACA carrier sense multiple accesscollision avoidance
ETSI European Telecommunication StandardInstitute
EVM error vector magnitude
FEC forward error correction
FFT fast fourier transform
GI guard interval
HIPERLAN high performance local area network
HISAW high-speed wireless area network
IEEE Institute of Electrical and Electronic Engineering
IFFT inverse fast fourier transform
MAC medium access control
MMAC multimedia mobile access communication
OFDM orthogonal frequency division multiplexing
PA power amplifier
PHY physical layer
PHY-SAP physical layer service access point
PPDU PLCP protocol data unit
PSDU PLCP service data unit
QAM quadrature amplitude modulation
QPSK quadrature phase shift keying
SDU service data unit
WLAN wireless local area network
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ReferencesIEEE Std 80211a-1999 Part 11 Wireless LAN Medium Access Control (MAC) and1Physical Layer (PHY) Specification High-speed Physical Layer in the 5GHZ BandETSI TS 101 475 v121 Broadband Radio Access Networks (BRAN) HIPERLAN Type22 Physical (PHY) LayerETSI TS 101 761-1 v111 Broadband Radio Access Networks (BRAN) Data Link3Control (DLC) Layer Part1 Basic Data Transport FunctionsH Sudo K Ishikawa and G-i Ohta OFDM Transmission Diversity Scheme For4MMAC Systems Proceedings of VTC Spring 2000 Vol1 pp410-414Richard Van Nee and Ramjee Prasad OFDM For Wireless Multimedia5Communications Artech House Publishers Boston amp London 1999IEEE Std 80211b-1999 Part 11 Wireless LAN Medium Access Control (MAC) and6Physical Layer (PHY) Specifications Higher-Speed Physical Layer Extension in the 24GHz BandIEEE Std 80211-1999 Part 11 Wireless LAN Medium Access Control (MAC) and7Physical Layer (PHY) Specifications
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Channel and Channel CodingComponents
WLAN 11aConvDecoder (wlan)WLAN ConvCoder (wlan)WLAN ConvDecoder (wlan)WLAN Deinterleaver (wlan)WLAN Interleaver (wlan)WLAN PuncCoder (wlan)WLAN PuncCoderP1 (wlan)WLAN PuncConvCoder (wlan)WLAN PuncDecoder (wlan)WLAN PuncDecoder1 (wlan)WLAN PuncDecoderP1 (wlan)WLAN Scrambler (wlan)
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WLAN_11aConvDecoder
Description 11a viterbi decoderLibrary WLAN Channel CodingClass SDFWLAN_11aConvDecoderDerived From WLAN_ViterbiDecoder1
Parameters
Name Description Default Type Range
TrunLen path memory truncation length 60 int [20 200)
InputFrameLen input bits 288 int [2 infin)
Pin Inputs
Pin Name Description Signal Type
1 input code words to be viterbi-decoded
real
Pin Outputs
Pin Name Description Signal Type
2 output decoded bits int
NotesEquations
This component is used to viterbi-decode the input code words burst by burst and the1initial state of the decoder is all zero InputFrameLen2 output tokens are producedwhen InputFrameLen input tokens are consumedViterbi Decoding Algorithm2CC(217) is used as an example in the following algorithm The generator functionsof the code are g0 which equals 133 (octal) and g1 which equals 171 (octal)Because the constraint length is 7 there are 64 possible states in the encoder In theViterbi decoder all states are represented by a single column of nodes in the trellis atevery symbol instant At each node in the trellis there are 2 merging paths the pathwith the shortest distance is selected as the survivorIn WLAN systems the encoded packets are very long it is impractical to store theentire length of the surviving sequences before determining the information sequencewhen decoding delay and memory is concerned Instead only the most recent Linformation bits in each surviving sequence are stored Once the path with theshortest distance is identified the symbol associated with the path L periods ago isconveyed to the output as a decoded information symbol Generally parameter L(normally L ge 5K) is sufficiently large for the present symbol of the survivingsequences to have a minimum effect on decoding of the L th previous symbol InWLAN systems L=TrunLenThe following is the Viterbi algorithm for decoding a CC(nkK) code where K is theconstraint length of convolutional code In our components the convolutional code is
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processed with k=1Branch Metric Calculation
Branch metric at the J th instant of the α path through the trellis is defined asthe logarithm of the joint probability of the received n-bit symbol
conditioned on the estimated transmitted n-bit symbol
for the α path That is
If receiver is regarded as a part of the channel for the Viterbi decoder the channelcan be considered as an AWGN channel Therefore
Path Metric Calculation
The path metric for the α path at the J th instant is the sum of the branchmetrics belonging to the α path from the first instant to the J th instant Therefore
Information Sequence UpdateThere are 2 k merging paths at each node in the trellis and the decoder selects from
paths the one having the largest metric namely
and this path is known as the survivorDecoder OutputWhen the survivor has been determined at the J th instant the decoder outputs the (J-L )th information symbol from its memory of the survivor with the largest metric
References
IEEE Std 80211a-1999 Part 11 Wireless LAN Medium Access Control (MAC) and1
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Physical Layer (PHY) specifications High-speed Physical Layer in the 5 GHz Band1999S Lin and D J Costello Jr Error Control Coding Fundamentals and Applications 2Prentice Hall Englewood Cliffs NJ 1983
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WLAN_ConvCoder
Description Convolutional coding the input bitsLibrary WLAN Channel CodingClass SDFWLAN_ConvCoder
Pin Inputs
Pin Name Description Signal Type
1 input bits to becoded
int
Pin Outputs
Pin Name Description Signal Type
2 output coded bits int
NotesEquations
This model is used to perform normal convolutional encoding of data rate 12 over1the input signalEach firing 1 token is consumed and 2 tokens are producedReferring to the following figure the generator polynomial is G 1 = 133 oct for output2
A and G 2 = 171 oct for output B
Convolutional Code of Rate 12 (Constraint Length=7)
References
IEEE Standard 80211a-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer in the 5 GHz
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Band 1999
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WLAN_ConvDecoder
Description Bit by bit viterbi decoder for 11a convolutional codeLibrary WLAN Channel CodingClass SDFWLAN_ConvDecoderDerived From WLAN_ViterbiDecoder
Parameters
Name Description Default Type Range
SymbolLen path memory truncation length 10 int (0 infin)
Pin Inputs
Pin Name Description Signal Type
1 input The code words to be viterbi-decoded real
Pin Outputs
Pin Name Description Signal Type
2 output the decodedbits
int
NotesEquations
This component is used to viterbi-decode the input code words CC(217) and g01133 g1 171 is decoded There is a delay the length of which is equal to the memorylength of convolutional code Padding bits detect when the code words endOne output token is produced when 2 input tokens are consumedThe Viterbi decoding algorithm is described using CC(217) as an example2Generator functions of the code are g0 which equals 133 (octal) and g1 which equals171 (octal)Because the constraint length is 7 there are 64 possible states in the encoder In theViterbi decoder all states are represented by a single column of nodes in the trellis atevery symbol instant At each node in the trellis there are 2 merging paths the pathwith the shortest distance is selected as the survivorIn WLAN systems the encoded packets are very long it is impractical to store theentire length of the surviving sequences before determining the information sequencewhen decoding delay and memory is concerned Instead only the most recent Linformation bits in each surviving sequence are stored Once the path with theshortest distance is identified the symbol associated with the path L periods ago isconveyed to the output as a decoded information symbol Generally parameter L issufficiently large normally L ge 5K for the present symbol of the surviving sequencesto have a minimum effect on decoding of the L th previous symbol In WLANsystems L=8timesSymbolLenThe following is the Viterbi algorithm for decoding a CC(nkK) code where K is theconstraint length of convolutional code In our components the convolutional code is
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processed with k=1Branch Metric Calculation
Branch metric at the J th instant of the α path through the trellis is defined as
the logarithm of the joint probability of the received n-bit symbol conditioned on the estimated transmitted n-bit symbol
for the α path That is
If Rake receiver is regarded as a part of the channel for the Viterbi decoder thechannel can be considered as an AWGN channel Therefore
Path Metric Calculation
The path metric for the α path at the J th instant is the sum of the branchmetrics belonging to the α path from the first instant to the J th instant Therefore
Information Sequence Update
There are 2 k merging paths at each node in the trellis from paths thedecoder selects the one having the largest metric namely
this path is known as the survivorDecoder OutputWhen the two survivors have been determined at the J th instant the decoderoutputs the ( J-L )th information symbol from its memory of the survivor with thelargest metric
References
IEEE Standard 80211a-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer in the 5 GHz
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Band 1999S Lin and D J Costello Jr Error Control Coding Fundamentals and Applications 2Prentice Hall Englewood Cliffs NJ 1983
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WLAN_Deinterleaver
Description Deinterleave the input bitsLibrary WLAN Channel CodingClass SDFWLAN_Deinterleaver
Parameters
Name Description Default Type
Rate data rate Mbps_6 Mbps_9 Mbps_12 Mbps_18 Mbps_24 Mbps_27 Mbps_36Mbps_48 Mbps_54
Mbps_6 enum
Pin Inputs
Pin Name Description Signal Type
1 input input bits to be deinterleaved real
Pin Outputs
Pin Name Description Signal Type
2 output deinterleavedbits
real
NotesEquations
This model is used as a deinterleaver for HIPERLAN2 and IEEE 80211a It performs1the inverse relation of an interleaver and is defined by two permutationsj will be used to denote the index of the original received bit before the firstpermutation i denotes the index after the first and before the second permutation kdenotes the index after the second permutation just prior to delivering the codedbits to the convolutional (Viterbi) decoderThe first permutation is defined by
i = s times floor(js) + (j + floor(16 times j N CBPS )) mod s j = 01 N CBPS - 1
The value of s is determined by the number of coded bits per subcarrier N DBPS
according to
s = max( N DBPS 2 1)
The second permutation is defined by
k = 16 times i - ( N CBPS - 1)floor(16 times i N CBPS ) i = 0 1 N CBPS - 1
where N DBPS and N CBPS are determined by data rates listed in the following table
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Rate-Dependent Values
Data Rate(Mbps)
Modulation CodingRate (R)
Coded Bits perSubcarrier(NBPSC)
Coded Bits perOFDM Symbol(NCBPS)
Data bits perOFDM Symbol(NDBPS)
6 BPSK 12 1 48 24
9 BPSK 34 1 48 36
12 QPSK 12 2 96 48
18 QPSK 34 2 96 72
24 (IEEE 80211a) 16-QAM 12 4 192 96
27 (HIPERLAN2) 16-QAM 916 4 192 108
36 16-QAM 34 4 192 144
48 (IEEE 80211a) 64-QAM 23 6 288 192
54 64-QAM 34 6 288 216
References
IEEE Standard 80211a-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer in the 5 GHzBand 1999ETSI TS 101 475 v111 Broadband Radio Access Networks (BRAN) HIPERLAN Type22 Physical (PHY) layer April 2000
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WLAN_Interleaver
Description Interleave the input bitsLibrary WLAN Channel CodingClass SDFWLAN_Interleaver
Parameters
Name Description Default Type
Rate data rate Mbps_6 Mbps_9 Mbps_12 Mbps_18 Mbps_24 Mbps_27 Mbps_36Mbps_48 Mbps_54
Mbps_6 enum
Pin Inputs
Pin Name Description Signal Type
1 input input bits to beinterleaved
int
Pin Outputs
Pin Name Description Signal Type
2 output interleavedbits
int
NotesEquations
This model is used for HIPERLAN2 and IEEE 80211a Encoded data bits are1interleaved by a block interleaver with a block size corresponding to the number ofbits in a single OFDM symbol N CBPS
The interleaver is defined by a two-step permutation The first permutation ensures2that adjacent coded bits are mapped onto nonadjacent subcarriers The secondpermutation ensures that adjacent coded bits are mapped alternately onto less andmore significant bits of the constellation thereby avoiding long runs of low reliabilitybitsk will be used to denote the index of the coded bit before the first permutation i willdenote the index after the first and before the second permutation j will denote theindex after the second permutation just prior to modulation mappingThe first permutation is defined by
i = ( N CBPS 16) (k mod 16) + floor(k16) k = 0 1 N CBPS - 1
The function floor () denotes the largest integer not exceeding the parameterThe second permutation is defined by
j = s times floor(is) + (i + N CBPS - floor(16 times i N CBPS )) mod s i = 0 1 N
- 1
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CBPS
where
s is determined by the number of coded bits per subcarrier N DBPS
according to
s = max ( N DBPS 2 1)
where N DBPS and N CBPS are determined by data rates listed in the following table
Rate-Dependent Values
Data Rate(Mbps)
Modulation CodingRate (R)
Coded Bits perSubcarrier(NBPSC)
Coded Bits perOFDM Symbol(NCBPS)
Data Bits perOFDM Symbol(NDBPS)
6 BPSK 12 1 48 24
9 BPSK 34 1 48 36
12 QPSK 12 2 96 48
18 QPSK 34 2 96 72
24 (IEEE 80211a) 16-QAM 12 4 192 96
27 (HIPERLAN2) 16-QAM 916 4 192 108
36 16-QAM 34 4 192 144
48 (IEEE 80211a) 64-QAM 23 6 288 192
54 64-QAM 34 6 288 216
References
IEEE Standard 80211a-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer in the 5 GHzBand 1999ETSI TS 101 475 v111 Broadband Radio Access Networks (BRAN) HIPERLAN Type22 Physical (PHY) layer April 2000
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WLAN_PuncCoder
Description Puncture coderLibrary WLAN Channel CodingClass SDFWLAN_PuncCoder
Parameters
Name Description Default Type
Rate data rate Mbps_6 Mbps_9 Mbps_12 Mbps_18 Mbps_24 Mbps_27 Mbps_36Mbps_48 Mbps_54
Mbps_6 enum
Pin Inputs
Pin Name Description Signal Type
1 input input signal to be perforated anytype
Pin Outputs
Pin Name Description Signal Type
2 output output signal after perforated anytype
NotesEquations
This model is used to perforate the input convolutional code to produce a punctured1convolutional code Each firing K tokens are consumed and N tokens are producedK and N are determined by Rate according to the following tableRate K N
Mbps_6 2 2
Mbps_9 6 4
Mbps_12 2 2
Mbps_18 6 4
Mbps_24 (IEEE 80211a) 2 2
Mbps_27 (HIPERLAN2) 18 16
Mbps_36 6 4
Mbps_48 (IEEE 80211a) 4 3
Mbps_54 6 4
Typically punctured convolutional code is generated by perforating a mother2convolutional code according to a certain pattern to achieve a different data rateThis model determines the perforation pattern according to the Rate selected theinput convolutional coded bits are read to determine whether to output the input bitor simply discard it according to the pattern in the following figure
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Puncturing and Transmit Sequence
References
IEEE Standard 80211a-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer in the 5 GHzBand 1999ETSI TS 101 475 v111 Broadband Radio Access Networks (BRAN) HIPERLAN Type22 Physical (PHY) layer April 2000
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WLAN_PuncCoderP1
Description Puncture coder pattern P1Library WLAN Channel CodingClass SDFWLAN_PuncCoderP1
Pin Inputs
Pin Name Description Signal Type
1 input input signal to be perforated anytype
Pin Outputs
Pin Name Description Signal Type
2 output output signal after perforated anytype
NotesEquations
This model is used to perforate the input convolutional code to produce a punctured1convolutional code 26 tokens are consumed at input port and 24 tokens areproduced after the star is firedPunctured convolutional code is usually generated by perforating a mother2convolutional code according to a certain pattern This model is rate independent Itreads the input convolutional coded bits and determines either to output the input bitor simply discard it according to the pattern given in the following table
PDU-Wise Bit Numbering Puncture Pattern Transmit Sequence(after pallel-to-serial conversion)
0-155 X 1111110111111Y 1111111111110
X 1 Y 1 X 2 Y 2 X 3 Y 3 X 4 Y 4 X 5 Y 5 X 6 Y 6X 8 Y 7 X 9 Y 8 X 10 Y 9 X 11 Y 10 X 12 Y 11 X 13 Y 12
References
ETSI TS 101 475 v121 Broadband Radio Access Networks (BRAN) HIPERLAN Type12 Physical (PHY) layer November 2000ETSI TS 101 761-1 v111 Broadband Radio Access Networks (BRAN) Data Link2Control (DLC) Layer Part1 Basic Data Transport Functions April 2000
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WLAN_PuncConvCoder
Description Punctured convolutional encoderLibrary WLAN Channel CodingClass SDFWLAN_PuncConvCoder
Parameters
Name Description Default Type Range
Rate rate determining punctured convolutional code type Mbps_6 Mbps_9Mbps_12 Mbps_18 Mbps_24 Mbps_27 Mbps_36 Mbps_48 Mbps_54
Mbps_6 enum
Length octet number of PSDU 100 int [14095]
Pin Inputs
Pin Name Description Signal Type
1 input signal to be encoded int
Pin Outputs
Pin Name Description Signal Type
2 output encoded signal int
NotesEquations
This subnetwork is used to perform punctured convolutional encoding over the input1signal The schematic for this subnetwork is shown in the following figure
WLAN_PuncConvCoder Schematic
A convolutional coding model is used to encode into mother convolutional code of2data rate 12 A puncture encoder model is used to generate punctured convolutionalcode The Rate parameter determines the type of WLAN punctured convolutionalcodeBefore convolutional coding 8 zero bits are inserted after NDATA bits Beforepunctured coding 16 zero bits are discarded The number of OFDM symbols (DATA
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part) N SYM is
N SYM = Ceiling ((16 + 8 times Length + 6) N DBPS )
where N DBPS is determined by data rate according to the following table
NDATA is NDBPS times N SYM
Data Rate(Mbps)
Modulation CodingRate (R)
Coded Bits perSubcarrier(NBPSC)
Coded Bits perOFDM Symbol(NCBPS)
Data Bits perOFDM Symbol(NDBPS)
6 BPSK 12 1 48 24
9 BPSK 34 1 48 36
12 QPSK 12 2 96 48
18 QPSK 34 2 96 72
24 16-QAM 12 4 192 96
27 16-QAM 916 4 192 108
36 16-QAM 34 4 192 144
48 64-QAM 23 6 288 192
54 64-QAM 34 6 288 216
Referring to the following figure the generator polynomial G 1 = 133 oct for A output3
is and G 2 = 171 oct for B output
Mother Convolutional Code of Rate 12 (Constraint Length=7)
References
IEEE Standard 80211a-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer in the 5 GHzBand 1999ETSI TS 101 475 v111 Broadband Radio Access Networks (BRAN) HIPERLAN Type22 Physical (PHY) layer April 2000
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WLAN_PuncDecoder
Description Puncture decoderLibrary WLAN Channel CodingClass SDFWLAN_PuncDecoder
Parameters
Name Description Default Type
Rate data rate Mbps_6 Mbps_9 Mbps_12 Mbps_18 Mbps_24 Mbps_27 Mbps_36Mbps_48 Mbps_54
Mbps_6 enum
Pin Inputs
Pin Name Description Signal Type
1 input input signal to berefilled
real
Pin Outputs
Pin Name Description Signal Type
2 output output signal after refilled real
NotesEquations
This model is used to refill the coding that was perforated during the puncture1encoding process It interpolates a zero value to the punctured data stream to form afull-length data stream The perforation pattern is determined based on Rate it theninterpolates zero into the input bits to form the outputEach firing K tokens are consumed and N tokens are produced K and N aredetermined according to the following tableRate K N
Mbps_6 2 2
Mbps_9 4 6
Mbps_12 2 2
Mbps_18 4 6
Mbps_24 (IEEE 80211a) 2 2
Mbps_27 (HIPERLAN2) 16 18
Mbps_36 4 6
Mbps_48 (IEEE 80211a) 3 4
Mbps_54 4 6
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Puncture and Transmit Sequence
References
IEEE Standard 80211a-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer in the 5 GHzBand 1999ETSI TS 101 475 v111 Broadband Radio Access Networks (BRAN) HIPERLAN Type22 Physical (PHY) layer April 2000
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WLAN_PuncDecoder1
Description Punctured convolutional decoderLibrary WLAN Channel CodingClass SDFWLAN_PuncDecoder1
Parameters
Name Description Default Type Range
Rate rate determining punctured convolutional code type Mbps_6 Mbps_9Mbps_12 Mbps_18 Mbps_24 Mbps_27 Mbps_36 Mbps_48 Mbps_54
Mbps_6 enum
SymbolLen path memory truncation length 10 int (0 infin)
Pin Inputs
Pin Name Description Signal Type
1 input signal to bedecoded
real
Pin Outputs
Pin Name Description Signal Type
2 output decoded signal real
NotesEquations
This subnetwork is used to perform punctured convolutional decoding of data rate112 over the input signal The schematic is shown in the following figure
WLAN_PuncDecoder1 Schematic
Punctured convolutional encoded input is decoded to normal convolutional codeddata A general Viterbi convolutional decoder is used for further decodingThe data rate of the mother convolutional code is 12 generator polynomials for Xoutput is G 1 = 171 oct and G 2 = 133 oct for Y output
References
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IEEE Standard 80211a-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer in the 5 GHzBand 1999S Lin and D J Costello Jr Error Control Coding Fundamentals and Applications2Prentice Hall Englewood Cliffs NJ 1983
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WLAN_PuncDecoderP1
Description Puncture decoder pattern P1Library WLAN Channel CodingClass SDFWLAN_PuncDecoderP1
Pin Inputs
Pin Name Description Signal Type
1 input input signal to berefilled
real
Pin Outputs
Pin Name Description Signal Type
2 output output signal after refilled real
NotesEquations
This model depunctures data that was perforated during the puncture encoding1processEach firing 24 tokens are consumed at input port and 26 tokens are producedThis model is rate independent It interpolates zero value to the punctured data2stream to form a full-length data stream according to the pattern shown in thefollowing tablePDU-Wise Bit Numbering Puncture Pattern Transmit Sequence
(after pallel-to-serial conversion)
0-155 X 1111110111111Y 1111111111110
X 1 Y 1 X 2 Y 2 X 3 Y 3 X 4 Y 4 X 5 Y 5 X 6 Y 6X 8 Y 7 X 9 Y 8 X 10 Y 9 X 11 Y 10 X 12 Y 11 X 13 Y 12
References
ETSI TS 101 475 v121 Broadband Radio Access Networks (BRAN) HIPERLAN Type12 Physical (PHY) layer November 2000ETSI TS 101 761-1 v111 Broadband Radio Access Networks (BRAN) Data Link2Control (DLC) Layer Part1 Basic Data Transport Functions April 2000
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WLAN_Scrambler
Description Scramble the input bitsLibrary WLAN Channel CodingClass SDFWLAN_Scrambler
Parameters
Name Description Default Type Range
InitState initial state of scrambler 1 0 1 1 1 01
intarray
0 or 1array sizeis 7
Length octet number of PSDU 100 int [1 4095]
Rate data rate Mbps_6 Mbps_9 Mbps_12 Mbps_18 Mbps_24Mbps_27 Mbps_36 Mbps_48 Mbps_54
Mbps_6 enum
Pin Outputs
Pin Name Description Signal Type
1 output scramblesequence
int
NotesEquations
This model is used for HIPERLAN2 and IEEE 80211a to generate scramble sequence1used for scrambling and descramblingThe length-127 frame synchronous scrambler (the following figure) uses thegenerator polynomial S(x) as follows When the all ones initial state is used the 127-bit sequence generated repeatedly by the scrambler (left-most used first) is
00001110 11110010 11001001 00000010 00100110 00101110 1011011000001100 11010100 11100111 10110100 00101010 11111010 0101000110111000 1111111
The same scrambler is used to scramble transmitted data and descramble receiveddata
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Data Scrambler
According to IEEE 80211a the initial state of the scrambler is set to a pseudo2random non-zero state The seven LSBs of the SERVICE field will be set to all zerosprior to scrambling to enable estimation of the initial state of the scrambler in thereceiverAccording to HIPERLAN2 all PDU trains belonging to a MAC frame are transmitted3by using the same initial state for scrambling Initialization is performed as follows
Broadcast PDU train in case AP uses one sector scrambler initialized at the5th bit of BCH at the 1st bit of FCH at the 1st bit of ACH without priorityand at the 1st bit of ACH with priorityBroadcast PDU train in case AP uses multiple sectors scrambler initializedat the 5th bit of BCHFCH and ACH PDU train transmitted only in the case of a multiple sectorAP scrambler initialized at the 1st bit of FCH at the 1st bit of ACH withoutpriority and at the 1st bit of ACH with priorityDownlink PDU train uplink PDU train with short preamble uplink PDU trainwith long preamble and direct link PDU train scrambler initialized at the1st bit of the PDU train
The initial state is set to a pseudo random non-zero state determined by the Framecounter field in the BCH at the beginning of the corresponding MAC frame The Framecounter field consists of the first four bits of BCH represented by ( n 4 n 3 n 2 n 1) 2and is transmitted unscrambled n 4 is transmitted first The initial state is derived byappending ( n 4 n 3 n 2 n 1) 2 to the fixed binary number (111) 2 in the form (111 n
4 n 3 n 2 n 1) 2 For example if the Frame counter is given as (0100) 2 the initial
state of the scrambler will be (1110100) 2 The transport channel content starting
with (10011101000) 2 will be scrambled to (00111110011) 2
References
IEEE Standard 80211a-1999 Part 11 Wireless LAN Medium Access Control (MAC)1and Physical Layer (PHY) specifications High-speed Physical Layer in the 5 GHzBand 1999ETSI TS 101 475 v111 Broadband Radio Access Networks (BRAN) HIPERLAN Type22 Physical (PHY) layer April 2000
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Measurements for WLAN Design LibraryWLAN 80211a BERPER (wlan)WLAN 80211a Constellation (wlan)WLAN 80211a EVM (wlan)WLAN 80211a RF EVM (wlan)WLAN DSSS CCK PBCC EVM (wlan)
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WLAN_80211a_BERPER
Description Bit and packet error rate measurements sinkLibrary WLAN MeasurementsClass SDFWLAN_80211a_BERPER
Parameters
Name Description Default Type Range
Length octet number of PSDU 256 int [1 4095]
Delay delay number of PSDUs 2 int [0 infin)
Start start frame of PSDUs 100 int [0 infin)
Stop stop frame of PSDUs 100 int [Startinfin)
Pin Inputs
Pin Name Description Signal Type
1 ref reference input PSDU int
2 test received PSDU int
NotesEquations
This subnetwork measures bit and packet error rates The schematic for this1subnetwork is shown in the following figureThe reference signal of IEEE 80211a and the received signal inputs are fed into thissubnetwork bit and packet error rates are saved and can be displayed in a DataDisplay window
WLAN_80211a_BERPER Schematic
References
IEEE Standard 80211a-1999 Part 11 Wireless LAN Medium Access Control (MAC)1
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and Physical Layer (PHY) specifications High-speed Physical Layer in the 5 GHzBand 1999