Cdma2000 1x Principle

7/28/2019 Cdma2000 1x Principle

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ORA000003 CDMA2000 Principle

ISSUE4.0

ORA000003 CDMA2000 Principle

ISSUE4.0

HUAWEI, Mobile Network Curriculum Development Section

ObjectivesObjectives

After this presentation, you will be familiar with:

the development of mobile communication system

the structure of CDMA2000 network

the number planning in CDMA2000 network

the techniques used by CDMA system including:

source coding, channel coding, interleaving, scrambling,

spreading and modulation etc.

power control, soft handoff, RAKE receiverF-PCH,F-PICH,F-SYNCH,F-FCH,F-SCH,R-ACH,R-PICH

Long code, short code and Walsh code


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Transmission TechniquesTransmission Techniques

Traffic channels: differentusers are assigned uniquecode and transmitted overthe same frequency band,for example, WCDMA andCDMA2000

Traffic channels: different frequency bandsare allocated to different users,for example,AMPS and TACS

Traffic channels: different time slotsare allocated to different users, forexample, DAMPS and GSM

Frequ

ency

Time

Power

Frequ

ency

Time

Power

Frequ

ency

Time

Power

FDMA

TDMA

CDMA

User

User

User

UserUser

User

Introduction

3G Objectives3G Objectives

3G is developed to achieve:

Universal frequency band for standard and seamless

global coverage

High spectral efficiency

High quality of service with complete security and

reliability

Easy and smoothly transition from 2G to 3G, compatible

with 2G

Provide multimedia services, with the rates:

Vehicle environment: 144kbps

Walking environment: 384kbps

Indoor environment: 2Mbps

Introduction


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Standards for 3GStandards for 3G

3G system

CDMA2000

3GPP2

FDD mode

WCDMA

3GPP

FDD mode

TD-SCDMA

CWTS

TDD mode

Introduction

A Comparison b/w 3G standardsA Comparison b/w 3G standards

WCDMA CDMA2000 TD-SCDMA

Receiver type RAKE RAKE RAKE

Close loop powercontrol Supported Supported Supported

Handoff Soft/hard handoff

Demodulationmode

Coherent

Chip rate (Mcps) 3.84 N*1.2288 1.28

Transmissiondiversity mode

TSTD, STTDFBTD

OTD, STS No

Synchronizationmode

Asynchronous Synchronous Asynchronous

Core network GSM MAP ANSI-41 GSM MAP

CoherentCoherent

Soft/hard handoffSoft/hard handoff

Introduction


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IS95A9.6kbps

IS95B115.2kbps

CDMA2000 307.2kbps

Heavier voiceservice capacity ;

Longer period ofstandby time

CDMA20003X

CDMA20001X EV

1X EV-DO

1X EV-DV

1995 1998

2000

2003

Development of CDMADevelopment of CDMA

Higher spectrum efficiency and network capacity

Higher packet data rate and more diversified services

Smooth transit to 3G

Introduction

Frequency Allocation In CDMA2000Frequency Allocation In CDMA2000

Band Class 0 and Spreading Rate 1

Introduction

892.170-893.310847.170-848.310739-777ValidB(2.5MHz)

890.670-890.820845.670-845.820689-694ValidA(1.5MHz)

880.680-889.320835.680-844.320356-644ValidB(10MHz)

870.030-879.330825.030-834.3301-311ValidA(10MHz)

Base StationMobile StationCDMA

Channel

Number

CDMA

Channel

Validity

Block

Designator

Transmit Frequency Band (MHz)

The transmit frequence point for Base Station is computed by:

F=870+N*0.03

N: CDMA Channel Number


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Frequency Allocation In CDMA2000Frequency Allocation In CDMA2000

Band Class 1 and Spreading Rate 1

Introduction

1971.250-1973.7501891.250-1893.750825-875ValidF(5MHz)

1966.250-1968.7501886.250-1888.750725-775ValidE(5MHz)

1976.250-1988.7501896.250-1908.750925-1175ValidC(15MHz)

1951.250-1963.7501871.250-1883.750425-675ValidB(15MHz)

1946.250-1948.7501866.250-1868.750325-375ValidD(5MHz)

1931.250-1943.7501851.250-1863.75025-275ValidA(15MHz)

Base StationMobile StationCDMA

Channel

Number

CDMA

Channel

Validity

Block

Designator

Transmit Frequency Band (MHz)

The transmit frequence point for Base Station is computed by:

F=1930+N*0.05

N: CDMA Channel Number

CDMA2000 1X Network StructureCDMA2000 1X Network Structure

MS: Mobile Station BTS: Base Transceiver StationBSC: Base Station Controller MSC: Mobile Switching CenterHLR :Home Location Register VLR: Visitor Location RegisterPCF: Packet data Control Function PDSN: Packet Data Service NodeHA: Home Agent FA: Foreign AgentSCP: Service Control Point Radius: Remote Authentication Dial-in User Service

Abis

A1(Signaling)

A2(Traffic)

A11(Signaling)

A10(Traffic)

A3(Signaling & Traffic)

A7(Singaling)

Introduction


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Course ContentsCourse Contents

Chapter 1 Introduction

Chapter 2 CDMA Techniques & Technologies

Chapter 3 CDMA Air Interface

Chapter 4 CDMA Number planning

CorrelationCorrelation

(a)

(b)

Correlation 100% so thefunctions are parallel

Correlation 0% so thefunctions are orthogonal

CDMA Techniques & Technologies+1

-1

+1

-1

+1

-1

+1


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Orthogonal FunctionOrthogonal Function

Orthogonal functions have zero correlation. Two binary

sequences are orthogonal if their XOR output contains equal

number of 1s and 0s

0000

01010101

EXAMPLE:

CDMA Techniques & Technologies

1010

01011111

Information spreading over orthogonal codesInformation spreading over orthogonal codes


1 0 0 1 1

0110 0110 0110 0110 0110

1001 0110 0110 1001 1001

User Input

OrthogonalSequence

Tx Data

+1

-1

+1

-1


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Information recoveryInformation recovery


1 0 0 1 1+1

-1

Rx Data 1001 0110 0110 1001 10010110 0110 0110 0110 01101111 0000 0000 1111 1111

Correct Function

? ? ? ? ?

Rx Data 1001 0110 0110 1001 10010101 0101 0101 0101 0101

1100 0011 00111100 1100

Incorrect Function

Spreading and De-spreadingSpreading and De-spreading

information pulse interference White noise

The improvement of time-domain information rate means that the bandwidth of spectrum-domain

information is spread.

S(f) is the energy density.

f

Sf

The spectrum before spreading

information

f0

The spectrum before despreading

information

Interference/noise

Sf

f0 f f0

The spectrum after despreading

information

Interference/noise

Sf

f

The spectrum after spreading

information

f0

Sf

f



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Signal flowSignal flow

InterleavingSourcecoding

Convolution&

Interleaving

Scrambling Spreading Modulation

RFtransmission

Sourcedecoding

deinterleavingDecovolution

&Deinterleaving

Unscrambling De-spreading DemodulationRF receiving


Common Technical TermsCommon Technical Terms

Bit, Symbol, Chip:

A bit is the input data which contain information

A symbol is the output of the convolution, encoder, and the

block interleaving

A chip is the output of spreading

Processing Gain:

Processing gain is the ratio of chip rate to the bit rate.

The processing gain in IS-95 system is 128, about 21dB.

Forward direction: Information path from base station to

mobile station

Reverse direction: Information path from mobile station to

base station



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Source CodingSource Coding

Vocoder:8K QCELP

13K QCELP

EVRC

Characteristics

Support voice activity


Channel CodingChannel Coding

Convolution code or TURBO code is used in channel encoding

Constraint length=shift register number+1.

Encoding efficiency= (total input bits / total output symbols)

convolution encoder

Input (bits) Output (symbols)



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Turbo CodeTurbo Code

Turbo code is used during the transmission of large data packet.

Characteristics of the Turbo code:

The input information is encoded twice and the two output codes can

exchange information with each other during decoding.

The symbol is protected not only by the neighborhood check bits,

but also by the separate Check Bits.

The performance of a Turbo code is superior to that of a convolution

code.


InterleavingInterleaving

The direction of the data stream

1 2 873 64 5

1 2 873 64 5

1 2 873 64 5

1 2 873 64 5

1 2 873 64 5

1 2 873 64 5

1 2 873 64 51 2 873 64 51 2 873 64 5

1 2 873 64 5

1 1 111 11 1

2 2222

7 7 777 77 7

6 6 666 66 6

3 3 333 33 3

4 4 444 44 4

1 2 873 64 51 2 873 64 55 5 555 55 5

8 8 888 88 8

interleaving


2 2 2


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Out

0 0 1

1 1 0

Scrambling (M) sequenceScrambling (M) sequence

Two points are important here:

Maximum number of shift register (N)

Mask

The period of out put sequence is 2N-1 bits

Only sequence offset is change when the mask is changed

PN stands for Pseudorandom Noise sequence


Long CodeLong Code

The long code is a PN sequence with period of 242-1chips

The functions of a long code:

Scramble the forward CDMA channel

Control the insertion of power control bit

Spread the information on the reverse CDMA channel to identify

the mobile stations



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PNa

PNc

PNb

Short CodeShort Code


Short code is a PN sequence with period of 215 chips Sequence with different time offset is used to distinguish

different sectors

Minimum PN sequence offset used is 64 chips, that is, 512 PN

offsets are available to identify the CDMA sectors (215/64=512).

Walsh CodeWalsh Code

W2n=Wn Wn

Wn Wn

W1=0

W2=0 0

0 1

W4 =

0 00 1

0 00 1

0 00 1

Walsh code

64-order Walsh function is used as a spreading function and

each Walsh code is orthogonal to other.

Walsh Code is one kind of orthogonal code.

A Walsh can be presented by Wim where ith (row) is the

position and m is the order. For example, W24 means 0101

code in W4 matrix


1 1

1 0


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In forward direction, each symbol is spread with Walsh code

Walsh code is used to distinguish the user in forward link

For IS95A/B, in the reverse, every 6 symbols correspond to one

Walsh code. For example, if the symbol input is 110011,the

output after spreading is W5164 (110011=51).

For CDMA2000, in the reverse, Walsh function is used to define

the type of channel (RC 3-9)

Walsh CodeWalsh Code


Variable Walsh codesVariable Walsh codes

64

48

16

32

12

96 00 1 920 0 38 400 76 800 1 536 00 307200 614400

Data rate -bps-

W01=0

W02=00

W12=01

W04=0000

W24=0011

W14=0101

W34=0110

W08=00000000

W48=00001111

W28=00110011

W68=00111100

W18=01010101

W58=01011010

W38=01100110

W78 =01101001

( W016,W

816)

( W416,W12

16)

( W216,W14

16)

( W616,W14

16)

( W116,W

916)

( W516,W

1316)

( W316,W11

16)

( W716,W15

16)

The different Walsh codescorresponding to different data rates



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Modulation-QPSKModulation-QPSK

I

Q

I channel PN sequence1.2288Mcps

Q channel PN sequence

1.2288Mcps

Baseband filter

Baseband filter

Cos(2pfct)

Sin(2pfct)

I(t)

Q(t)

s(t)A

1.2288Mcps: the PN chip rate of the system.

After being spread, all the forward channels in the same carrier are

modulated by means of QPSK(OQPSK in the reverse), converted

into simulation signals and transmitted after clustering.


Power Control

Handoff

Diversity and RAKE



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Power ControlPower Control

Reverse power control

Open loop power control

Closed loop power control

Inner loop power control: 800 Hz

Outer loop power control

Forward power control

Message transmission mode:

threshold transmission

periodic transmission


Reverse Open Loop Power ControlReverse Open Loop Power Control

The transmission power required by the mobile station is determined by

the following factors:

Distance from the base station

Load of the cell

Circumstance of the code channels

The transmission power of the mobile station is relative to its received

power.

BTSMobile

Reverse Open LoopPower Control

BTS

BTS

TransmittingPower



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Reverse Closed Loop Power ControlReverse Closed Loop Power Control

BTS

Power Control Bit

Eb/Nt Value FER Value

Inner Loop Power Control

Outer Loop Power Control

Change in Eb/Nt Value


BSC

BTS

Forward Power ControlForward Power Control

MS measures the frame quality and informs the base station

to the result i.e. whether it is in the threshold or periodical

mode. Base station determines whether to change the

forward transmitting power or not.

In IS-95 system, the forward power control is slow but in

CDMA2000 system it is fast.


Message Transmission Mode


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HandoffHandoff

Soft handoffIt is a process of establishing a link with a target sector beforebreaking the link with the serving sector

Softer handoffLike the soft handoff, but the handoff is occurred betweenmulti-sectors in the same base station

Hard handoffHard handoff occurs when the two sectors are notsynchronized or are not on the same frequency. Interruption in

voice or data communication occurs but this interruption doesnot effect the user communication


Soft/Softer HandoffSoft/Softer Handoff

Multi-path combination in the BSC during soft handoff

Multi-path combination in the BTS during softer handoffs

Combine all the

power from eachsector

Power received froma single sector



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Pilot SetPilot Set

ActiveSet

CandidateSet

NeighborSet

RemainingSet

The pilot set, corresponding to the basestation being connected

The pilot set, not in the active set butpotential to be demodulated

The pilot set, not included in the active set orthe candidate set but being possible to beadded in the candidate set

Other pilot sets

the set of the pilots having same frequency but different PN sequence offset


T_ADD,T_DROP,T_TDROPT_ADD,T_DROP,T_TDROP

Time

Ec/Io

SectorA Sector

B

Guard Time(T-TDROP)

Add Threshold (T_ADD)

DropThreshold (T_DROP)

Soft Handoff Region

T_ADD, T_DROP and T_TDROP affect the percentage of MS in handoff.

T_ADD & T_DROP is the standards used to add or drop a pilot.

T_DROP is a timer.



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Comparison ThresholdComparison Threshold

Pilot P1

Pilot P2

Pilot P0

t0

T_COMP0.5dB

t1 t2

T_ADD

Pilot strength

P0-Strengh of Pilot P0 in Candidate Set.P1,P2-Stength of Pilot P1,P2 in Active Set.

t0-Pilot strength Measurement Message Sent, P0>T_ADD

t1-Pilot strength Measurement Message Sent, P0>P1+T_COMP*0.5dB

t2 -Pilot strength Measurement Message Sent, P0>P2+T_COMP*0.5dB


Transition Between Pilot SetsTransition Between Pilot Sets

T_ADD

T_DROP

Pilot 1

Pilotstrength

Pilot 2

T_TDROP

NeighborSet

CandidateSet

ActiveSet

CandidateSet

NeighborSet

TIME1 2 3 4 5 6 7



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Transmit DiversityTransmit Diversity

Time diversity

Block interleaving, error-correction

Frequency diversity

The CDMA signal energy is distributed on the whole 1.23MHZ

bandwidth.

Space diversity

The introduction of twin receive antennas .

The RAKE receivers of the mobile station and the base station

can combine the signals of different time delay.

During a handoff, the mobile station contacts multiple base

stations and searches for the strongest frame


Transmission DiversityTransmission Diversity

The forward transmission diversity types in

CDMA2000 1X are

TD (Transmit Diversity)

OTD (Orthogonal Transmit Diversity)

The data stream is divided into two parts, which will be spread

by the orthogonal code sequence, and transmitted by two

antennas.

STS (Space Time Spreading)

All the forward code channels are transmitted by the multi-

antennas.



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Transmission DiversityTransmission Diversity

The Transmission Diversity Technology enhances the receive performance of MS.

Transmissiondiversity

processing

Data stream 1

Data stream 2

Data stream Restoring data stream

Path1

Path2

Antenna 2

Antenna 1


The Principle of RAKE ReceiverThe Principle of RAKE Receiver

RAKE antennas help to overcome on the multi-path fading and enhance

the receive performance of the system

Receive set

Correlator 1

Correlator 2

Correlator 3

Searcher correlatorCalculate the

time delay andsignal strength

Combiner The combinedsignal

tt

s(t) s(t)



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Chapter 3 CDMA Air interface

Chapter 4 CDMA Core Network

Physical Channel in IS-95APhysical Channel in IS-95A

Forward channel

Forward Pilot Channel

Forward Sync Channel

Forward Paging Channel

Forward Traffic Channel (including power control sub-

channel)

Reverse channel

Access Channel

Reverse Traffic Channel

CDMA Air Interface


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Pilot channel(all-zeros)

W064

Pilot ChannelPilot Channel

A pilot channel:

Assist mobile station to be connected with CDMA network

Handles multi-path searching

Provide the phase reference for coherent demodulation and help the mobile

station estimate the transmission power

The mobile station measures and compares the pilot channel powers from

the base stations during the handoff

Forward pilot channel is spread over W0 and modulated with short code directly

BTS transmits the pilot channel continuously

CDMA Air Interface

ToQPSK

coder

2.4kbps 4.8kbps 4.8kbps

Codesymbol

Repetitivecode

symbol

1.2kbps

Convolutionencoderr=1/2,K=9

symbolrepetition

Blockinterleaving

Sync Ch bits

W3264

Sync ChannelSync Channel

The sync channel is used by the mobile station to synchronize with

the network. W32 is used to spread Sync Channel.

The synchronization message includes:

Pilot PN sequence offset: PILOT_PN System time: SYS_TIME

Long code state: LC_STATE

Paging channel rate: P_RAT

Here note that, sync channel rate is 1200bps

CDMA Air Interface


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ToQPSK

coder

Pagingchannel bits

19.2/9.6Kbps 19.2kbps

19.2kbpsCode

symbol

9.6/4.8 kbps

Convolutionencoder

r=1/2,K=9

Symbolrepetition

Blockinterleaving

Paging channel addressmask

Longcode PN

generator

decimator

1.2288Mcps

19.2kbps

Repetitive

codesymbol

Paging ChannelPaging Channel

The paging channel transmits:

System parameters message

Access parameters

Neighbors list

CDMA channels list message

The paging channel accomplishes:

Paging to MS Assign traffic channel to MS

The frame length of a paging channel is 20ms

W1 ~ W7 are spared for the Paging Channels spreading

CDMA Air Interface

W164

Forward Traffic ChannelForward Traffic Channel

I Ch PN sequence (1.2288 Mcps)

PN 1.2288 Mcps

Repetitivesymbol

19.2kbps

8.6kbps9.6kbps

4.8kbps

2.4kbps

1.2kbps

Add framequality indicatorbits(12,10,8,6)

Add 8encoded tail

bits

Convolutionencoder

r=1/2,K=9

Symbolrepetition

Forward trafficchannal

(172/80/40 or16bits/frame)

Blockinterleaver

19.2kbps

MUX

Long codegenerator

Power control bits

Q Ch PN sequence (1.2288 Mcps)

Basebandfilter

I(t)

Q(t)decimator

+QPSK Modulation

4.0kbps2.0kbps0.8kbps

19.2ksybps

9.6ksybps

4.8ksybps

2.4ksybps

Sin(2pfct)

Cos(2pfct)

is used to transmit data and signaling information.

Walsh code

CDMA Air Interface

decimator

+

+Baseband

filter

+

+


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Reverse Access ChannelReverse Access Channel

4.8 kbps (307.2kbps)

PN chips1.2288 McpsOrthogonal spreading

Repetitivesymbol

28.8 kbps

Codesymbol

14.4 kbps4.4 kbps 4.8kbpsAdd 8encoder tail

bits

Convolutionencoder

r=1/3,K=9

SymbolrepetitionAccess

channel(80 bits/frame)

Blockinterleaving

28.8 kbps

Data burstrandomizer

Long codePN

generator

Frame rate

Long code mask

Repetitivesymbol

used by MS to initiate communication or respond to Paging Channel

Walsh code

CDMA Air Interface


Basebandfilter

I(t)

Q(t)

QPSK Modulation

Sin(2pfct)

Cos(2pfct)

+

+Baseband

filter

+

+


1/2 PN chips Delayedtime=406.9ns

Reverse Traffic ChannelReverse Traffic Channel

used to transmit data and signaling information

CDMA Air Interface

8.6kbps9.6kbps

4.8kbps

2.4kbps

1.2kbps

Add framequality indicatorbits(12,10,8,6)

Add 8encoded tail

bits

convolutionencoder

r=1/3,K=9

Symbolrepetition

Reverse trafficchannel

(172/80/40 or16 bits/frame)

Blockinterleaver

4.0kbps2.0kbps

0.8kbps

28.8Ksybps

14.4Ksybps

7.2Ksybps

3.6Ksybps

4.8 kbps (307.2kbps)PN chips

1.2288 McpsOrthogonal spreading

Data burstrandomizer

Long codePN

generator

Frame rate

Long code mask

Walsh code


Basebandfilter

I(t)

Q(t)

QPSK Modulation

Sin(2pfct)

Cos(2pfct)

+

+Baseband

filter

+

+


1/2 PN chips Delayedtime=406.9ns


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Initialization of the MSInitialization of the MS

Synchronous Channel message contains the LC_STATE,

SYS_TIME, P_RAT, and synchronizes with the system.

CDMA Air Interface

BTS

Pilotch

annel

Synchr

onousc

hannel

Paging

channe

l

Access

channe

l

CDMA2000 Forward ChannelCDMA2000 Forward Channel

Forward CDMA2000 channel

F-CACH F-CPCCH F-PICH F-CCCH

F-DCCH F-FCH

F-PC F-SCCH F-SCH

F-PICH F-TDPICH F-APICH F-ATDPICH

F-SYNCH F-TCH F-BCH F-PCH F-QPCH

subchannel (RC1~2) (RC3~9)

Note: Only the channels with black color are being implemented in

Huawei equipment. The function of F-PICH, F-SYNCH, F-FCH, F-PC,F-SCCH, F-PCH are the same as those of IS95. We will only discuss

F-SCH, F-QPCH F-DCCH in the following slides.

CDMA Air Interface


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Forward channelForward channel

These channels are newlydefined in CDMA2000 system.

CDMA physical channels are classified in common channels and dedicated channels:Common physical channels:

Forward Pilot Channel(F-PICH)

Forward Synchronous Channel(F-SYNC)

Forward Paging Channel(F-PCH)

Forward Broadcast Control Channel(F-BCCH)

Forward Quick Paging Channel(F-QPCH)

Forward Common Power Control Channel(F-CPCCH)

Forward Common Assignment Channel(F-CACH)

Forward Common Control Channel(F-CCCH)

These channels are compatiblewith IS-95 system

Dedicated physical channel:

Forward Dedicated Control Channel(F-DCCH)

Forward Fundamental Channel(F-FCH)

Forward Supplemental Channel(F-SCH)

These channels are used to establish the connection between a base station and a

specific mobile station.

The CDMA2000 system adopts multiple data rates and the different combinations of

channels can achieve a performance superior to that in IS-95 system.

CDMA Air Interface

F-QPCHF-QPCH

It transmits OOK-modulated signal which can be demodulated by

MS simply and rapidly.

The channel adopts 80ms as a QPCH timeslot. Each timeslot is

divided into paging indicators, configuration change indicators

and broadcast indicators, all of which are utilized to inform the

MS whether to receive paging message, broadcast message or

system parameters in the next F-PCH.

Rapid and simple demodulation. MS no need to monitor F-PCH

for long time, so the standby time is prolonged.

CDMA Air Interface


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F-SCHF-SCH

F-SCH is typically used for high speed data

applications, while F-FCH is used for common

voice and low speed data application.

When a data call is established, firstly, F-FCH will

be allocated to the user. If the speed of data for

user exceeds 9.6kbps, F-SCH will be allocated.

CDMA Air Interface

F-DCCHF-DCCH

It is used for the transmission of specific user

signaling information during a call.

Each forward traffic channel may contain one F-DCCH.

Support 5ms frame.

Support discontinuous transmission.

CDMA Air Interface


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Forward Radio Configuration (RC)Forward Radio Configuration (RC)

Radio Configuration(RC):

A set of Forward Traffic channel and Reverse Traffic Channel transmission

formats that are characterized by physical parameters such as data rates,

modulation characteristics, and spreading rate.

Spreading Rate: Equivalent to chips rate, e.g., 1.2288Mcps.

RadioConfiguration

SpreadingRate

Max Data Rate*(kbps)

Effective FECCode Rate

OTDAllowed

FEC Encoding Modulation

1** 1 9.6 1/2 No Conv. BPSK

2** 1 14.4 3/4 No Conv BPSK

3 1 153.6 1/4 Yes Conv and Turbo QPSK





8 3 460.8 1/4 or 1/3 Yes Conv and Turbo QPSK

9 3 1036.8 1/2or 1/3 Yes Conv and Turbo QPSK

**Same as IS95

CDMA Air Interface

Reverse ChannelReverse Channel

Reverse CDMA2000 channel

R-ACHR-TCH

operation(RC1~2)

R-EACHoperation

R-CCCHoperation

R-SCCH

R-FCH

R-TCHoperation(RC3~6)

R-EACH

R-PICH

R-CCCH

R-PICH

R-DCCH

R-PICH

0~7 0~1

R-SCH

R-FCH

0~2

0~1

subchannel

R-PC

Only the channels in dark color are used in Huawei

equipment. The function of R-ACH,R-FCH,R-SCCHare the same as those in IS95. We will only discuss

R-PICH,R-SCH in the following slides.

CDMA Air Interface


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Types of Reverse ChannelTypes of Reverse Channel

Reverse channel includes reverse common channel

and reverse dedicated channel.

Reverse common channel:

Reverse Access Channel(R-ACH)

Reverse Enhanced Access Channel(R-EACH)

Reverse Common Control Channel(R-CCCH)

Reverse Dedicated Channel

Reverse Pilot Channel(R-PICH)

Reverse Dedicated Control Channel(R-DCCH)

Reverse Fundamental Channel(R-FCH)

Reverse Supplemental Channel(R-SCH)

Reverse Supplemental Code Channel (R-SCCH)

CDMA Air Interface

MUX A

Pilot( all '0's)

Power Control Bit

Reverse Pilot Channel

R-PICHR-PICH

The Function of Reverse Pilot Channel

Initialization

Tracing

Reverse Coherent Demodulation

Power Control Measurement

Base station enhances the received performance and

increases the capacity by means of coherent demodulation of

the Reverse Pilot Channel.

CDMA Air Interface


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Reverse ChannelsReverse Channels

Fundamental Channel: Fundamental Channel is used for the transmission of user

information to the base station during a call, and can be used to

transmit defaulted voice services as an independent Traffic

Channel.

Dedicated Control Channel

The Dedicated Control Channel is used for the transmission of

user and signaling information to a base station during a call.

Supplemental Channel/Supplemental Code Channel

These channels are used for the transmission of user information,

mainly data services, to the MS. The Reverse Traffic Channelcontains up to two supplemental channels and up to seven

supplemental code channels.

CDMA Air Interface

Reverse Radio Configuration (RC)Reverse Radio Configuration (RC)

RC: Radio Configuration

RC1~RC2:IS-95A/B

RC3~RC4:CDMA2000 1X

RC5~RC6: CDMA2000 3x

Radio

Configuration

Spreading

Rate

Max Data Rate*

(kbps)

Effective FEC

Code Rate

OTD

AllowedFEC Encoding Modulation

1** 1 9.6 1/3 No Conv 64-ary ortho

2** 1 14.4 1/2 No Conv 64-ary ortho

3 1 153.6 1/4 Yes Conv or Turbo BPSK

(307.2) (1/2)

4 1 230.4 3.8 Yes Conv or Turbo BPSK


(614.4) (1/3)


(1036.8) (1/2)

**Same as IS95

CDMA Air Interface


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RC 1

RC 2

RC 3

RC 4

RC 5

RC 1

RC 2

RC 3

RC 4

RC 5

RC 3

RC 4

RC 4

RC 3

F-FCH RCs

R-DCCH/SCHRCsF-DCCH/SCHRCs

R-FCH RCs

RC Combination RegulationRC Combination Regulation

RC1 and RC2 corresponds

respectively to rate set 1 and rate set

2 in IS- 95A/B system.

CDMA2000 Forward RC: RC1~RC5

Reverse RC: RC1~RC4

Rules:

Forward RC1, Reverse RC1


Forward RC3 or RC4,Reverse RC3


CDMA Air Interface




Chapter 3 CDMA Air Interface

Chapter 4 CDMA Number Planning


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Definition of Coverage AreasDefinition of Coverage Areas

Location area

MSC area

PLMN area

Service area

Sectorarea

CDMA Number Planning

Cell area

Parameters InvolvedParameters Involved

In a CDMA system, the following parameters are

defined to identify a user and his location:

MIN/IMSI

MDN

ESN

TLDN

SID/NID

LAI

GCI

SIN

SSN



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MIN/IMSIMIN/IMSI

Mobile subscriber identity/international mobile subscriber identityFor example, 0907550001/460030907550001

Not more than 15 digits

3 digits 2 digits

IMSI

MCC MNC MSIN

NMSI


MDNMDN

CC + MAC + H 0H 1H 2H 3 + ABCD

International mobile subscriber DN

National valid mobile subscriber number

Mobile directory number

For example, 8613307550001



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ESNESN

A unique Electronic Serial Number (ESN) is used to identify single

MS. An ESN includes 32 bits and has the following structure:

31......24 23......18 17......0 bit

Manufacturers number retained equipment SN

For example, FD 03 78 0A (the 10th Motorola 378 mobile phone)

The equipment serial number is allocated by a manufacturer.


TLDNTLDN

+CC MAC H0H 1H2 ABC+ ++44

Temporary local directory number

For example, 8613344755001



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SID/NIDSID/NID

MSCID (Exchange Identity)

= System Identity (SID) + Exchange number (SWIN)

is used to represent a certain set of equipment in an

NSS network. For example,

Unicom CDMA Shenzhen MSC is labeled as 3755+01


Location Area Identity (LAI)Location Area Identity (LAI)

PAGING message is broadcast within a local area, the size ofwhich depends on traffic, paging bearer capability, signaling flow ,

etc.

Format: MCC+MNC+LAC

MCC: Mobile Country Code, 3 digits. For example, China is 460.

MNC: Mobile Network Code, 2 digits. For example, the MNC of

Unicom is 03.

LAC: Location Area Code, a 2-byte-long hexadecimal BCD code.0000 cannot be used with FFFE.

For example, 460030100



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Global Cell Identity (GCI)Global Cell Identity (GCI)

The unique ID of a cell in PLMN

Format: LAI+CI

CI: Cell Identity, a 2-byte-long hexadecimal BCD code,

pre defined by the engineering department. The first 3

digits and the last digit represent the base station

number and the sector number respectively. For an

omni-directional site, the last digit of CI is 0.

For example, 4600301001230 shows base station number

123 contains an omni-directional site


ReviewReview

Chips rate: 1.2288Mcps

IS-95A/B is a subset, RC1/RC2

Apply the coherent demodulation to the reverse pilot

channel

Forward transmit diversity: OTD and STS

Forward quick power control at 800HZ rate

Improve the standby time by introducing the quick paging

channel.

Variable frames: 5ms, 20ms, 40ms and 80ms Introduce TURBO code into channel encoding

The maximum rate of a physical layer is up to 307.2K

CDMA Technology


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Development of CDMA Standards in ChinaDevelopment of CDMA Standards in China

CDMA standards currently adopted in China are mainly

based on the USA standards with few alterations. For

example, in USA the emphasis is put on the dual service

support i.e. CDMA and AMPS compatibility, while in China

there is no such requirement. Therefore, the settings of

frequency and basic channels, IMSI and others parameters

need to be modified. Likewise, there is also the need to

modify network interface IS-41 series of standards.

Case study: China Unicom NetworkCase study: China Unicom Network

In China Unicom CDMA project, phase 1, a narrow-band CDMA

network, named IS-95B (enhanced IS-95) is being constructed.

With total capacity is 15,000,000, subscribers handling, covering

over 200 cities.

Currently, both nationwide and international roaming tests have

conducted successfully with the CDMA networks of HongKong,

South Korea and Japan via the TSI international gateway bureau.

Besides, a CDMA intelligent network will be constructed to

provide intelligent value-added services like Pre-Paid Charging(PPC) and Virtual Private Network (VPN) etc.

The whole CDMA20001X network was launched in air in the

second half of 2002.


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Why CDMA2000?Why CDMA2000?

Increase the system capacity

Forward quick power control

Forward transmit diversity: OTD,STS

Coherent modulation applied on the pilot channel.(about

3dB)

The introduction to Turbo code

The stronger ability to resist interference

The improved error-correcting encoding

(applying Turbo code in medium/high rate

data transmission)

Why CDMA2000?Why CDMA2000?

Support high rate SCH, with the maximum rate

of a single channel being up to 307.2kbps.

Improve the standby time

Use the quick paging channel

Forward compatibility

Radio-frequency part

Baseband part, such as RC


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SummarySummary

Brief Development History of MobileCommunication

Analog--digital--code division

Objectives of 3G and comparison of 3 systems

Technical features of CDMA

Key technologies: power control, soft handoff,RAKE receiver

and cell breath

Other technologies: source coding, channel coding,

interleaving, scrambling, spreading and modulation

Channel structure: pilot, synchronization, paging, access and

service

Technical features of CDMA2000 1X Walsh and Turbo codes

QuestionsQuestions

What power control modes are there in CDMA2000

system and how are they implemented?

Describe the soft handoff process?

Describe the process and functions of cell breath?

Describe the implementation process of service

channels (forward and reverse)?

Describe the technical features of CDMA2000?

Describe the initialization process of a mobile phone?

What are the functions of a long code, short codeand Walsh code in CDMA system?


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Documents

Cdma2000 1x Principle