Owa010010 Wcdma Ran Overview Issue 1.13

8/20/2019 Owa010010 Wcdma Ran Overview Issue 1.13

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Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

WCDMA RAN Overview


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Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved. Page2

Contents

1. 3G Overview

2. CDMA Principle

3. WCDMA Network Architecture and protocol structure

4. WCDMA Wireless Fundamental


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Different Service, Different Technology

AMPS

TACS

NMT

Others

1G 1980sAnalog

GSM

CDMA

IS-95

TDMAIS-136

PDC

2G 1990sDigital

Technologiesdrive

3GIMT-2000

UMTS

WCDMA

cdma2000

Demandsdrive

TD-SCDMA

3G provides compositive services for both operators and subscribers


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3G Evolution

Proposal of 3G

IMT-2000: the general name of third generation mobile

communication system

The third generation mobile communication was first proposed in1985，and was renamed as IMT-2000 in the year of 1996

Commercialization: around the year of 2000

Work band : around 2000MHz

The highest service rate :up to 2000Kbps


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3G Spectrum Allocation


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Bands WCDMA Used

Main bands 1920 ~ 1980MHz / 2110 ~ 2170MHz

Supplementary bands: different country maybe different

1850 ~ 1910 MHz / 1930 MHz ~ 1990 MHz (USA)

1710 ~ 1785MHz / 1805 ~ 1880MHz (Japan)

890 ~ 915MHz / 935 ~ 960MHz (Australia)

. . .

Frequency channel number＝central frequency×5, for mainband:

UL frequency channel number：9612～9888

DL frequency channel number : 10562～10838


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3G Application Service

Time Delay

Error Ratio

background

conversational

streaming

interactive


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The Core technology of 3G: CDMA

CDMA

WCDMA CN: based on MAP and GPRS

RTT: WCDMA

TD-SCDMA CN: based on MAP and GPRS

RTT: TD-SCDMA

cdma2000 CN: based on ANSI 41 and MIP

RTT: cdma2000


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Contents

1. 3G Overview

2. CDMA Principle




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Multiple Access and Duplex Technology

Multiple Access Technology

Frequency division multiple access (FDMA)

Time division multiple access (TDMA)

Code division multiple access (CDMA)


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Multiple Access Technology

Power

FDMA

Power

TDMA

Power

CDMA


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Multiple Access and Duplex Technology

Duplex Technology

Frequency division duplex (FDD)

Time division duplex (TDD)


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Duplex Technology

Time

Frequency

Power

TDD

USER 2

USER 1

DL

UL

DL

DL

UL

FDD

Time

Frequency

Power

UL DL

USER 2

USER 1


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Contents

1. 3G Overview

2. CDMA Principle




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WCDMA Network Version Evolution

3GPP Rel993GPP Rel4

3GPP Rel5

2000 2001 2002

GSM/GPRS CN

WCDMA RTT

IMS

HSDPA 3GPP Rel6

MBMS

HSUPA

2005

CS domain change to NGN

WCDMA RTT


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WCDMA Network Version Evolution

Features of R6

MBMS is introduced

HSUPA is introduced to achieve the service rate up to 5.76Mbps

Features of R7

HSPA+ is introduced, which adopts higher order modulation and MIMO

Max DL rate: 28Mbps, Max UL rate:11Mbps

Features of R8

HSPA+ PhaseII is introduced, which adopts 64QAM+MIMO or 64QAM+DC in

downlink (Defined by 3GPP 25.XXX) LTE is introduced which adopts OFDMA instead of CDMA (Defined by 3GPP

36.XXX)

Max DL rate: 100Mbps, Max UL rate: 50Mbps (with 20MHz bandwidth)


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Contents

1. 3G Overview

2. CDMA Principle




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Processing Procedure of WCDMA System

SourceCoding

Channel Coding& Interleaving

Spreading Modulation

SourceDecoding

Channel Decoding& Deinterleaving

Despreading Demodulation

Transmission

Reception

chipmodulated

signalbit symbol

ServiceSignal

RadioChannel

ServiceSignal

Receiver


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WCDMA Source Coding

AMR (Adaptive Multi-Rate) Speech A integrated speech codec with 8

source rates

The AMR bit rates can be controlled by

the RAN depending on the system loadand quality of the speech connections

Video Phone Service

H.324 is used for VP Service in CS

domain

Includes: video codec, speech codec,

data protocols, multiplexing and etc.

CODEC Bit Rate (kbps)

AMR_12.20 12.2 (GSM EFR)

AMR_10.20 10.2

AMR_7.95 7.95

AMR_7.40 7.4 (TDMA EFR)

AMR_6.70 6.7 (PDC EFR)

AMR_5.90 5.9

AMR_5.15 5.15

AMR_4.75 4.75


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Transmitter

SourceCoding



SourceDecoding



Transmission

Reception

chipmodulated

signalbit symbol

ServiceSignal

RadioChannel

ServiceSignal

Receiver


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WCDMA Block Coding - CRC

Block coding is used to detect if there are any uncorrected

errors left after error correction.

The cyclic redundancy check (CRC) is a common method of

block coding.

Adding the CRC bits is done before the channel encoding and

they are checked after the channel decoding.


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WCDMA Interleaving

Effect Interleaving is used to reduce the probability of consecutive bits error

Longer interleaving periods have better data protection with more delay

1110

1.........

............

...000

0100

0 0 1 0 0 0 0 . . . 1 0 1 1 1

1110

1.........

............

...000

01000 0 … 0 1 0 … 1 0 0 … 1 0 … 1 1

Inter-columnpermutation

Output bits

Input bits

Interleaving periods:

20, 40, or 80 ms


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SourceCoding



SourceDecoding



Transmission

Reception

chipmodulated

signalbit symbol

ServiceSignal

RadioChannel

ServiceSignal

Receiver


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Correlation

Correlation measures similarity between any two arbitrary signals.

Identical and Orthogonal signals:

Correlation = 0

Orthogonal signals

-1 1 -1 1

-1 1 -1 1

1 1 1 1

+1

-1

+1

-1

+1

-1

+1

-1

Correlation = 1Identical signals

-1 1 -1 1

1 1 1 1

-1 1 -1 1

C 1

C2+1

+1

C1

C2


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Orthogonal Code Usage - Coding

UE1: 1 －1

UE2: －1 1

C 1 : －1 1 －1 1 －1 1 －1 1

C2 : 1 1 1 1 1 1 1 1

UE1 c1：－1 1 －1 1 1 －1 1 －1

UE2 c2：－1－1－1－1 1 1 1 1

UE1

c1

UE2

c2：

－

2 0－

2 0 2 0 2 0


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Orthogonal Code Usage - Decoding

UE1

C 1 UE2 C 2: － 2 0 － 2 0 2 0 2 0

UE1 Dispreading by c1: －1 1 －1 1 －1 1 －1 1

Dispreading result: 2 0 2 0 － 2 0 － 2 0

Integral judgment: 4 (means 1) － 4 (means－1)

UE2 Dispreading by c2: 1 1 1 1 1 1 1 1

Dispreading result: －2 0 －2 0 2 0 2 0

Integral judgment: －4 (means－1) 4 (means 1)


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Spectrum Analysis of Spreading & Dispreading

Max allowed interference

Eb/NoRequirement

Power

Max interference caused byUE and others

Processing Gain

Ebit

Interference fromother UE Echip

Eb / No = Ec / No×PG


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Process Gain

Process Gain

Process gain differs for each service.

If the service bit rate is greater, the process gain is smaller, UE

needs more power for this service, then the coverage of this

service will be smaller, vice versa.

)ratebit

ratechiplog( 10Gainocess Pr


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Spreading Technology

Spreading consists of 2 steps:

Channelization operation, which transforms data symbols into chips

Scrambling operation is applied to the spreading signal

scramblingchannelization

Datasymbol

Chips afterspreading


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WCDMA Channelization Code

OVSF Code (Orthogonal Variable Spreading Factor) is used as

channelization code

SF = 8 SF = 1 SF = 2 SF = 4

C ch,1,0 = (1)

C ch,2,0 = (1,1)

C ch,2,1 = (1, -1)

C ch,4,0 = (1,1,1,1)

C ch,4,1 = (1,1,-1,-1)

C ch,4,2 = (1,-1,1,-1)

C ch,4,3 = (1,-1,-1,1)

C ch,8,0 = (1,1,1,1,1,1,1,1)

C ch,8,1 = (1,1,1,1,-1,-1,-1,-1)

C ch,8,2 = (1,1,-1,-1,1,1,-1,-1)

C ch,8,3 = (1,1,-1,-1,-1,-1,1,1)

C ch,8,4 = (1,-1,1,-1,1,-1,1,-1)

C ch,8,5 = (1,-1,1,-1,-1,1,-1,1)

C ch,8,6 = (1,-1,-1,1,1,-1,-1,1)

C ch,8,7 = (1,-1,-1,1,-1,1,1,-1)

……


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WCDMA Channelization Code

SF = chip rate / symbol rate

High data rates→ low SF code

Low data rates→ high SF code

Radio bearer SF Radio bearer SF

Speech 12.2 UL 64 Speech 12.2 DL 128

Data 64 kbps UL 16 Data 64 kbps DL 32





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Purpose of Channelization Code

Channelization code is used to distinguish different physical

channels of one transmitter

For downlink, channelization code ( OVSF code ) is used to

separate different physical channels of one cell

For uplink, channelization code ( OVSF code ) is used to separate

different physical channels of one UE


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Purpose of Scrambling Code

Scrambling code is used to distinguish different transmitters

For downlink, scrambling code is used to separate different cells in

one carrier

For uplink, scrambling code is used to separate different UEs inone carrier


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Scrambling Code

Scrambling code: GOLD sequence.

There are 224 long uplink scrambling codes which are used for

scrambling of the uplink signals. Uplink scrambling codes are assigned

by RNC.

For downlink, 512 primary scrambling codes are used.


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Primary Scrambling Code Group

Primaryscramblingcodes fordownlink

physicalchannels

Group 0

…

Primary scrambling

code 0

……

Primaryscrambling code

8*63

……

Primaryscrambling code

8*63 +7512 primary

scrambling

codes

………

…

Group 1

Group 63

Primary scramblingcode 1

Primary scramblingcode 7

64 primary

scrambling code

groups

Each group consists of 8

primary scrambling codes


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Code Multiplexing

Downlink Transmission on a Cell Level

Scrambling code

Channelization code 1



User 1 signal

User 2 signal

User 3 signal

NodeB


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SourceCoding



SourceDecoding



Transmission

Reception

chip modulatedsignalbit symbol

ServiceSignal

RadioChannel

ServiceSignal

Receiver


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Modulation Overview

1 00 1

time

Basic steady radio

wave:

carrier = A.cos(2 Ft+ )

Amplitude Shift

Keying:

A.cos(2

Ft+

)

Frequency Shift

Keying:

A.cos(2

Ft+

)

Phase Shift Keying:

A.cos(2

Ft+

)

Data to be transmitted:Digital Input


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Modulation Overview

Digital Modulation - BPSK

1

t

1 10

1

t-1

NRZ coding

f o

BPSK

Modulated

BPSKsignal

Carrier

Informationsignal

=0 =

=0

1 102 3 4 9875 6

1 102 3 4 9875 6

Digital Input

High Frequency

Carrier

BPSK Waveform


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Modulation Overview

Digital Modulation - QPSK

-1 -1

1 102 3 4 9875 6

1 102 3 4 9875 6

NRZ Input

I di-Bit Stream

Q di-Bit Stream

I

Component

Q

Component

QPSK Waveform

1

1

-1

1

-1

1

1

-1

-1

-1

1 1 -1 1 -1 1 1 -1


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WCDMA Modulation

Different modulation methods corresponding to different

transmitting abilities in air interface

HSDPA: QPSK or 16QAM R99/R4: QPSK


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SourceCoding

ChannelCoding


SourceDecoding

ChannelDecoding


Transmission

Reception

chip modulatedsignalbit symbol

ServiceSignal

RadioChannel

ServiceSignal

Transmitter

Receiver


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Owa010010 Wcdma Ran Overview Issue 1.13

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