Ora000003 Cdma2000 Principle (Wll) Issue4.0

8/6/2019 Ora000003 Cdma2000 Principle (Wll) Issue4.0

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HUAWEI TECHNOLOGIES CO., LTD.

All rights reserved

www.huawei.com

Internal

ORA000003 CDMA2000

Principle

ISSUE 4.0


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HUAWEI TECHNOLOGIES CO., LTD. Page 2All rights reserved

Upon completion of this course, you will be able to:

the development of mobile communication system

the techniques used by CDMA system including:source coding, channel coding, interleaving, scrambling,

spreading and modulation etc.

power control, soft handoff, RAKE receiver

F-PCH,F-PICH,F-SYNCH,F-FCH,F-SCH,R-ACH,R-PICH

Long code, Short code and Walsh code


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Chapter 1: IntroductionChap

ter 1: Introduction

Chapter 2: CDMA Techniques & TechnologiesChapter 2: CDMA Techniques & Technologies

Chapter 3: CDMA Air InterfaceChapter 3: CDMA Air Interface


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1st Generation

1980s (analog) 2

nd

Generation1990s (digital) 3rd

Generationcurrent (digital)

3G provides: Complete integrated service

solutions High bandwidth Unified air interface Best spectral efficiency and

a step towards PCS

AMPS

Analog to DigitalTACS

NMT

OTHERS

GSM

CDMA

IS95

TDMA

IS-136

PDC

UMTS

WCDMA

CDMA2000

TD-

SCDMA

Development of Mobile Communications Introduction

Voice to Broadband


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Transmission Techniques

Traffic channels: differentusers are assigned unique

code and transmitted over

the same frequency band,

for example, WCDMA and

CDMA2000

Traffic channels: different frequency bands

are allocated to different users,for example,

AMPS and TACS

Traffic channels: different time slots

are allocated to different users, for

example, DAMPS and GSM

Frequ

ency

Time

Power

Frequ

ency

Time

Power

Frequ

ency

Time

Power

FDMA

TDMA

CDMA

User

User

User

User

User

User

Introduction


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TDMA

Frequenc

y

Time

Power

user

us

er

user

user

user

Introduction


7/73HUAWEI TECHNOLOGIES CO., LTD. Page 7All rights reserved

3G 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: 144kbpsWalking environment: 384kbps

Indoor environment: 2Mbps

Introduction


8/73HUAWEI TECHNOLOGIES CO., LTD. Page 8All rights reserved

Standards for 3G

3G system

CDMA2000

3GPP2

FDD mode

WCDMA

3GPPFDD mode

TD-SCDMA

CWTS

TDD mode

Introduction


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A Comparison b/w 3G standards

WCDMA CDMA2000 TD-SCDMA

Receiver type RAKE RAKE RAKE

Close loop power

control Supported Supported Supported

Handoff Soft/hard handoff

Demodulation

modeCoherent

Chip rate (Mcps) 3.84 N*1.2288 1.28

Transmission

diversity mode

TSTD, STTD

FBTD OTD, STS No

Synchronization

modeAsynchronous Synchronous Asynchronous

Core network GSM MAP ANSI-41 GSM MAP

CoherentCoherent

Soft/hard handoffSoft/hard handoff

Introduction


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IS95A

9.6kbps

IS95A

115.2kbps

CDMA2000 307.2kbps

Heavier voiceservice capacity ;

Longer period ofstandby time

CDMA2000

3X

CDMA2000

1X EV

1X EV-DO

1X EV-DV1995 1998

2000

2003

Development of CDMA

Higher spectrum efficiency and network capacity

Higher packet data rate and more diversified services

Smooth transit to 3G

Introduction


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Frequency Allocation In CDMA2000

Band Class 0 and Spreading Rate 1

Introduction

Transmit Frequency Band (MHz)

Block

Designator

CDMA Channel

Validity

CDMA

Channel

Number

Mobile Station Base Station

A(10MHz) Valid 1-311 825.030-834.330 870.030-879.330

B(10MHz) Valid 356-644 835.680-844.320 880.680-889.320

A(1.5MHz) Valid 689-694 845.670-845.820 890.670-890.820

B(2.5MHz) Valid 739-777 847.170-848.310 892.170-893.310

The transmit frequence point for Base Station is computed by:

F=870+N*0.03

N: CDMA Channel Number


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HUAWEI TECHNOLOGIES CO., LTD. Page All rights reserved

Frequency Allocation In CDMA2000

Band Class 1 and Spreading Rate 1

Introduction

Transmit Frequency Band (MHz)

Block

Designator

CDMA

Channel

Validity

CDMA

Channel

Number

Mobile Station Base Station

A(15MHz) Valid 25-275 1851.250-1863.750 1931.250-1943.750

D(5MHz) Valid 325-375 1866.250-1868.750 1946.250-1948.750

B(15MHz) Valid 425-675 1871.250-1883.750 1951.250-1963.750

E(5MHz) Valid 725-775 1886.250-1888.750 1966.250-1968.750

F(5MHz) Valid 825-875 1891.250-1893.750 1971.250-1973.750

C(15MHz) Valid 925-1175 1896.250-1908.750 1976.250-1988.750

The transmit frequence point for Base Station is computed by:

F=1930+N*0.05

N: CDMA Channel Number


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HUAWEI TECHNOLOGIES CO., LTD. Page All rights reserved

CDMA2000 1X Network StructureIntroduction

LE

INTERNE

MIP HA

AAA

PDSN/FA

BSC/PCFAbis

BTS

BTS

BTS

BTSA10/A11

Um

IWF

Abis

V5

LEV5Optical

FiberSoftsite

Um

L

Remote Model

AbisE1/STM-1

A b is

M od ule

BSC/PCF/IWF


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Chapter 1: IntroductionChapter 1: Introduction




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Correlation

(a)

(b)

Correlation 100% so the

functions are parallel

Correlation 0% so the

functions are orthogonal

CDMA Techniques & Technologies

+1

-1

+1

-1

+1

-1

+1


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Orthogonal Function

Orthogonal functions have zero correlation. Two binary

sequences are orthogonal if their XOR output contains equal

number of 1s and 0s

0000

0101

0101

EXAMPLE:


1010

0101

1111


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Information spreading over orthogonal codesCDMA Techniques & Technologies

1 0 0 1 1

0110 0110 0110 0110 0110

1001 0110 0110 1001 1001

User Input

Orthogonal

Sequence

Tx Data

+1

-1

+1-1


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Information recovery CDMA Techniques & Technologies

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 1001

0101 0101 0101 0101 01011100 0011 0011 1100 1100

Incorrect Function


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Spreading 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

S f

The spectrum before spreading

information

f0

The spectrum before despreading

information

Interference/noise

S f

f0 f f0

The spectrum after despreading

information

Interference/noise

S f

f

The spectrum after spreading

information

f0

S f

f



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Signal flow

InterleavingSource

codingConvolution

&

Interleaving

Scrambling Spreading Modulation

RF

transmission

Source

decoding

deinterleavingDecovolution&

DeinterleavingUnscrambling De-spreading Demodulation

RF receiving



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Common Technical Terms

Bit, Symbol, Chip:

A bit is the input data which contain informationA 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 mobilestation

Reverse direction: Information path from mobile station to base

station



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In a typical duplex call, the duty ratio is less than 35%. To achieve

better capacity and low power consumption, base station reduces

its transmission power.

Source Coding

Vocoder:

8K QCELP

13K QCELP

EVRC

Characteristics

Support voice activity



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Channel 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 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 outputcodes 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.



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Out

0 0 1

1 1 0

Scrambling (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



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Long Code

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

The functions of a long code:

Scramble the forward CDMA channelControl 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 Code CDMA Techniques & Technologies

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).


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Walsh 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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Walsh Code

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)



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Variable Walsh codes

64

4

8

16

32

12

9600 19200 38400 76800 153600 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

W5

8=01011010

W38=01100110

W78=01101001

( W016,W

816)

( W416,W

1216)

( W216,W

1416)

( W616,W

1416)

( W116,W

916)

( W516,W1316)

( W316,W

1116)

( W716,W

1516)

The different Walsh codes

corresponding to different data rates



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Modulation-QPSK

I

Q

I channel PN sequence

1.2288Mcps

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.



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Power Control

Handoff Diversity and RAKE



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Power 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

Closed loop power control



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Reverse Open Loop Power Control

The transmission power required by the mobile station is determined by thefollowing 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 Loop

Power Control

BTS

BTS

Transmitting

Power



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Reverse 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


BSCBTS


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Forward 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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Forward Closed Loop Power Control

Compared with IS-95 system, CDMA2000 the forward quick

power control is fast.

Power Control Bit

Eb/Nt Value


BTS


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Handoff

Soft handoff

It is a process of establishing a link with a target sectorbefore breaking the link with the serving sector

Softer handoff

Like the soft handoff, but the handoff is occurred between

multi-sectors in the same base station

Hard handoff

Hard 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

does not effect the user communication



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Soft/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 each

sector

Power received from

a single sector



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Pilot Set

Active

Set

CandidateSet

Neighbor

Set

Remaining

Set

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 or

the candidate set but being possible to be

added in the candidate set

Other pilot sets

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



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T_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 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



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Transition Between Pilot Sets

T_ADD

T_DROP

Pilot 1

Pilot

strength

Pilot 2

T_TDROP

T_TDROP

Neighbor

Set

Candidate

Set

Active

Set

Candidate

Set

Neighbor

Set

TIME1 2 3 4 5 6 7 8



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Transmit 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



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Transmission 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, andtransmitted by two antennas.

STS (Space Time Spreading)

All the forward code channels are transmitted by the

multi-antennas.

Spread with the quasi-orthogonal code

Non-TD



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Transmission Diversity

The Transmission Diversity Technology enhances the receive

performance of MS.

Transmission

diversity

processing

Data stream 1

Data stream 2

Data stream Restoring data stream

Path1

Path2

Antenna 2

Antenna 1



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The 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 and

signal strength

Combiner The combined

signal

tt

s(t) s(t)



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Chapter 1: IntroductionChapter 1: Introduction




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Physical 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 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 channelpowers 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


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T

oQPSK

coder

2.4kbps 4.8kbps 4.8kbps

Code

symbol

Repetitive

codesymbol

1.2kbps

Convolution

encoderr=1/2,K=9

symbol

repetition

Block

interleaving

Sync Ch bits

W32 64

Sync Channel

The sync channel is used by the mobile station to synchronizewith 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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ToQ

PSK

coder

Paging

channel bits

19.2/9.6Kbps 19.2kbps

19.2kbps

Code

symbol

9.6/4.8 kbps

Convolutionencoder

r=1/2,K=9

Symbolrepetition

Block

interleaving

Paging channel address

mask

Long

code PN

generator

decimator

1.2288Mcps

19.2kbps

Repetitive

code

symbol

Paging 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


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Forward Traffic Channel

I Ch PN sequence (1.2288 Mcps)

PN 1.2288 Mcps

Repetitive

symbol

19.2kbps

8.6kbps9.6kbps

4.8kbps

2.4kbps

1.2kbps

Add frame

quality indicator

bits(12,10,8,6)

Add 8

encoded tail

bits

Convolution

encoderr=1/2,K=9

Symbol

repetition

Forward traffic

channal

(172/80/40

or

16bits/frame)

Block

interleaver

19.2kbps

MUX

Long code

generator

Power control bits

Q Ch PN sequence (1.2288 Mcps)

Baseband

filter

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 Channel

4.8 kbps

(307.2kbps)

PN chips

1.2288 McpsOrthogonal spreading

Repetitive

symbol8.8 kbps

Code

symbol

14.4 kbps4.4 kbps 4.8kbpsAdd 8

encoder tail

bits

Convolution

encoder

r=1/3,K=9

Symbol

repetitionAccess

channel

(80

bits/frame)

28.8 kbps

Data burst

randomizer

Long code

PN

generator

Frame rate

Long code mask

Repetitive

symbol

used by MS to initiate communication or respond to Paging Channel

Walsh code

CDMA Air Interface


Baseband

filter

I(t)

Q(t)

QPSK Modulation

Sin(2pfct)

Cos(2pfct)

+

+Baseband

filter

+

+


1/2 PN chips Delayed

time=406.9ns

Block

interleaving


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Reverse Traffic Channelused to transmit data and signaling information

CDMA Air Interface

8.6kbps9.6kbps

4.8kbps

2.4kbps

1.2kbps

Add framequality indicator

bits(12,10,8,6)

Add 8encoded tail

bits

convolutionencoder

r=1/3,K=9

Symbolrepetition

Reverse traffic

channel

(172/80/40 or

16

bits/frame)

Blockinterleaver

4.0kbps

2.0kbps

0.8kbps

28.8Ksybps

14.4Ksybps

7.2Ksybps

3.6Ksybps

4.8 kbps

(307.2kbps)

PN chips

1.2288 Mcps

Orthogonal spreading

Data burst

randomizer

Long code

PN

generator

Frame rate

Long code mask

Walsh code


Baseband

filter

I(t)

Q(t)

QPSK Modulation

Sin(2pfct)

Cos(2pfct)

+

+Baseband

filter

+

+


1/2 PN chips Delayed

time=406.9ns


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Initialization 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

onous

channe

l

Pagingchan

nel

Accesschan

nel


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CDMA2000 Forward Channel

Forward CDMA2000 channel

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

F-DCCH F-FCHF-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 channel

These channels are newly

defined 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 compatible

with 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


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F-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-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


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F-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)

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, modulationcharacteristics, and spreading rate.

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

Radio

Configuration

Spreading

Rate

Max Data Rate*

(kbps)

Effective FEC

Code Rate

OTD

Allowed 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




7 3 614.4 1/3 Yes Conv and Turbo QPSK8 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


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Reverse ChannelReverse CDMA2000 channel

R-ACHR-TCH

operation

(RC1~2)

R-EACH

operationR-CCCH

operation

R-SCCH

R-FCH

R-TCH

operation

(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-SCCH are 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 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


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MUX A

Pilot(all '0's)

Power Control Bit

N is the Spreading Rate number

Pilot PowerControl

Power Control Group

= 1536 NPN Chips

384 NPN Chips

Reverse Pilot Channel

R-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 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 ChannelThe 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 Channel

contains up to two supplemental channels and up to seven

supplemental code channels.

CDMA Air Interface


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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 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 RC2, Reverse RC2

Forward RC3 or RC4,Reverse RC3

Forward RC5, Reverse RC4

CDMA Air Interface


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Why CDMA2000?

Increase the system capacity

Forward quick power controlForward 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)


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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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Summary

Brief Development History of Mobile Communication

Analog--digital--code division

Objectives of 3G and comparison of 3 systems

Technical features of CDMA

Key technologies: power control, soft handoff,RAKEreceiver 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


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www.huawei.com

Thank You

Documents

Ora000003 Cdma2000 Principle (Wll) Issue4.0