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01-Wcdma Ran Overview

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Page 1: 01-Wcdma Ran Overview

www.huawei.com

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

WCDMA RAN Overview

Page 2: 01-Wcdma Ran Overview

Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved. Page3

Objectives

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

Describe the development of 3G

Outline the advantage of CDMA principle

Characterize code sequence

Outline the fundamentals of RAN

Describe feature of wireless propagation

Page 3: 01-Wcdma Ran Overview

Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved. Page4

Contents

1. 3G Overview

2. CDMA Principle

3. WCDMA Network Architecture and protocol

structure

4. WCDMA Wireless Fundamental

Page 4: 01-Wcdma Ran Overview

Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved. Page5

Different Service, Different Technology

AMPS

TACS

NMT

Others

1G 1980sAnalog

GSMGSM

CDMA CDMA IS-95IS-95

TDMATDMAIS-136IS-136

PDCPDC

2G 1990sDigital

Technologies drive

3G IMT-2000

UMTSUMTSWCDMAWCDMA

cdmacdma20002000

Demands drive

TD-SCDMA

TD-SCDMA

3G provides compositive services for both operators and subscribers

Page 5: 01-Wcdma Ran Overview

Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved. Page7

3G Evolution

Proposal of 3G

IMT-2000: the general name of third generation mobile

communication system

The third generation mobile communication was first

proposed in 1985 , 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

Page 6: 01-Wcdma Ran Overview

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3G Spectrum Allocation

Page 7: 01-Wcdma Ran Overview

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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 main band:

UL frequency channel number : 9612 ~ 9888 DL frequency channel number : 10562 ~ 10838

Page 8: 01-Wcdma Ran Overview

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3G Application Service

Time Delay

Error Ratio

background

conversational

streaming

interactive

Page 9: 01-Wcdma Ran Overview

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The Core technology of 3G: CDMA

CDMA

WCDMAWCDMACN: based on MAP and GPRS

RTT: WCDMA

TD-SCDMACN: based on MAP and GPRS

RTT: TD-SCDMA

cdma2000CN: based on ANSI 41 and

MIPRTT: cdma2000

Page 10: 01-Wcdma Ran Overview

Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved. Page12

Contents

1. 3G Overview

2. CDMA Principle

3. WCDMA Network Architecture and protocol

structure

4. WCDMA Wireless Fundamental

Page 11: 01-Wcdma Ran Overview

Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved. Page13

Multiple Access and Duplex Technology Multiple Access Technology

Frequency division multiple access (FDMA)

Time division multiple access (TDMA)

Code division multiple access (CDMA)

Page 12: 01-Wcdma Ran Overview

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Multiple Access Technology

Frequency

Time

Power

FDMA

FrequencyTime

Power

TDMA

Power

Time

CDMA

Frequency

Page 13: 01-Wcdma Ran Overview

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Multiple Access and Duplex Technology Duplex Technology

Frequency division duplex (FDD)

Time division duplex (TDD)

Page 14: 01-Wcdma Ran Overview

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Duplex Technology

Time

Frequency

Power

TDD

USER 2

USER 1

DL

ULDL

DL

UL

FDD

Time

Frequency

Power

UL DL

USER 2

USER 1

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Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved. Page17

Contents

1. 3G Overview

2. CDMA Principle

3. WCDMA Network Architecture and protocol

structure

4. WCDMA Wireless Fundamental

Page 16: 01-Wcdma Ran Overview

Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved. Page18

WCDMA Network Architecture

RNS

RNC

RNS

RNC

Core Network

Node B Node B Node B Node B

Iu-CS Iu-PS

Iur

Iub IubIub Iub

CN

UTRAN

UEUu

CS PS

Iu-CSIu-PS

CSPS

Page 17: 01-Wcdma Ran Overview

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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

Page 18: 01-Wcdma Ran Overview

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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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Uu Interface protocol structure

L3

contr

ol

contr

ol

contr

ol

contr

ol

C-plane signaling U-plane information

PHY

L2/MAC

L1

RLC

DCNtGC

L2/RLC

MAC

RLCRLCRLC

Duplication avoidance

UuS boundary

L2/BMC

control

PDCPPDCP L2/PDCP

DCNtGC

RRC

RLCRLCRLC

RLC

BMC

Page 20: 01-Wcdma Ran Overview

Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved. Page22

Contents

1. 3G Overview

2. CDMA Principle

3. WCDMA Network Architecture and protocol

structure

4. WCDMA Wireless Fundamental

Page 21: 01-Wcdma Ran Overview

Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved. Page23

Processing Procedure of WCDMA System

SourceCoding

Channel Coding& Interleaving Spreading Modulation

SourceDecodin

g

Channel Decoding& Deinterleaving

Despreading

Demodulation

Transmission

Reception

chipmodulated

signalbit symbol

Service

Signal

Radio Channel

Service

Signal

Receiver

Page 22: 01-Wcdma Ran Overview

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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 load and 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_12.2

0

12.2 (GSM

EFR)

AMR_10.2

0

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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Processing Procedure of WCDMA System

Transmitter

SourceCoding

Channel Coding& Interleaving Spreading Modulation

SourceDecodin

g

Channel Decoding& Deinterleaving

Despreading

Demodulation

Transmission

Reception

chipmodulated

signalbit symbol

Service

Signal

Radio Channel

Service

Signal

Receiver

Page 24: 01-Wcdma Ran Overview

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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.

Page 25: 01-Wcdma Ran Overview

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WCDMA Channel Coding

Effect

Enhance the correlation among symbols so as to recover the signal

when interference occurs

Provides better error correction at receiver, but brings increment of

the delay

Types

No Coding

Convolutional Coding (1/2, 1/3)

Turbo Coding (1/3)

Code Block of N Bits

No Coding

1/2 Convolutional Coding

1/3 Convolutional Coding

1/3 Turbo Coding

Uncoded N bits

Coded 2N+16 bits

Coded 3N+24 bits

Coded 3N+12 bits

Page 26: 01-Wcdma Ran Overview

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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-

column permutatio

n

Output bits

Input bits

Interleaving periods: 20, 40, or 80 ms

Page 27: 01-Wcdma Ran Overview

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Processing Procedure of WCDMA System

SourceCoding

Channel Coding& Interleaving Spreading Modulation

SourceDecodin

g

Channel Decoding& Deinterleaving

Despreading

Demodulation

Transmission

Reception

chipmodulated

signalbit symbol

Service

Signal

Radio Channel

Service

Signal

Receiver

Page 28: 01-Wcdma Ran Overview

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Correlation

Correlation measures similarity between any two arbitrary signals.

Identical and Orthogonal signals:

Correlation = 0Orthogonal 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

C1

C2

+1

+1

C1

C2

Page 29: 01-Wcdma Ran Overview

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Orthogonal Code Usage - Coding

UE1: + 1 - 1

UE2: - 1 + 1

C1 : - 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

UE1: + 1 - 1

UE2: - 1 + 1

C1 : - 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

Page 30: 01-Wcdma Ran Overview

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Orthogonal Code Usage - Decoding

UE1×C1 + UE2×C2: - 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)

UE1×C1 + UE2×C2: - 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)

Page 31: 01-Wcdma Ran Overview

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Spectrum Analysis of Spreading & Dispreading

Spreading code

Spreading code

Signal Combination

Narrowband signal

f

P(f)

Broadband signal

P(f)

f

Noise & Other Signal

P(f)

f

Noise+Broadband signal

P(f)

f

Recovered signal

P(f)

f

Page 32: 01-Wcdma Ran Overview

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Spectrum Analysis of Spreading & Dispreading

Max allowed interference

Eb/No Requirement

Power

Max interference caused by UE and others

Processing Gain

Ebit

Interference from other UE Echip

Eb / No = Ec / No ×PG

Page 33: 01-Wcdma Ran Overview

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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.

)rate bit

rate chiplog(10Gain ocessPr

Page 34: 01-Wcdma Ran Overview

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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

Data symbol

Chips after spreading

Page 35: 01-Wcdma Ran Overview

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WCDMA Channelization Code

OVSF Code (Orthogonal Variable Spreading Factor) is

used as channelization code

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

Cch,1,0 = (1)

Cch,2,0 = (1,1)

Cch,2,1 = (1, -1)

Cch,4,0 = (1,1,1,1)

Cch,4,1 = (1,1,-1,-1)

Cch,4,2 = (1,-1,1,-1)

Cch,4,3 = (1,-1,-1,1)

Cch,8,0 = (1,1,1,1,1,1,1,1)

Cch,8,1 = (1,1,1,1,-1,-1,-1,-1)

Cch,8,2 = (1,1,-1,-1,1,1,-1,-1)

Cch,8,3 = (1,1,-1,-1,-1,-1,1,1)

Cch,8,4 = (1,-1,1,-1,1,-1,1,-1)

Cch,8,5 = (1,-1,1,-1,-1,1,-1,1)

Cch,8,6 = (1,-1,-1,1,1,-1,-1,1)

Cch,8,7 = (1,-1,-1,1,-1,1,1,-1)

……

Page 36: 01-Wcdma Ran Overview

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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

Data 128 kbps UL 8 Data 128 kbps DL 16

Data 144 kbps UL 8 Data 144 kbps DL 16

Data 384 kbps UL 4 Data 384 kbps DL 8

Page 37: 01-Wcdma Ran Overview

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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

Page 38: 01-Wcdma Ran Overview

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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 in one carrier

Page 39: 01-Wcdma Ran Overview

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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.

Page 40: 01-Wcdma Ran Overview

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Primary Scrambling Code Group

Primary scrambling codes for downlink physical channels

Group 0

Primary scrambling

code 0

……

Primary scrambling code 8*63

……

Primary scrambling

code 8*63 +7512 primary scrambling

codes

……

……

Group 1

Group 63

Primary scrambling

code 1

Primary scrambling

code 7

64 primary scrambling code groups

Each group consists of 8 primary scrambling

codes

Page 41: 01-Wcdma Ran Overview

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Code Multiplexing

Downlink Transmission on a Cell Level

Scrambling codeScrambling code

Channelization code 1Channelization code 1

Channelization code 2Channelization code 2

Channelization code 3Channelization code 3

User 1 signal

User 2 signal

User 3 signal

NodeB

Page 42: 01-Wcdma Ran Overview

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Code Multiplexing

Uplink Transmission on a Cell Level

NodeB

Scrambling code 3

User 3 signal

Channelization code

Scrambling code 2

User 2 signal

Channelization code

Scrambling code 1

User 1 signal

Channelization code

Page 43: 01-Wcdma Ran Overview

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Processing Procedure of WCDMA System

SourceCoding

Channel Coding& Interleaving Spreading Modulation

SourceDecodin

g

Channel Decoding& Deinterleaving

Despreading

Demodulation

Transmission

Reception

chipmodulated

signalbit symbol

Service

Signal

Radio Channel

Service

Signal

Receiver

Page 44: 01-Wcdma Ran Overview

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Modulation Overview

1 00 1

time

Basic steady radio wave:

carrier = A.cos(2Ft+)

Amplitude Shift Keying:

A.cos(2Ft+)

Frequency Shift Keying:

A.cos(2Ft+)

Phase Shift Keying:

A.cos(2Ft+)

Data to be transmitted:Digital Input

Page 45: 01-Wcdma Ran Overview

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Modulation Overview

Digital Modulation - BPSK

1

t

1 10

1

t-1

NRZ coding

fo

BPSK

Modulated

BPSK signal

Carrier

Information signal

=0 = =0

1 102 3 4 9875 6

1 102 3 4 9875 6

Digital Input

High FrequencyCarrier

BPSK Waveform

Page 46: 01-Wcdma Ran Overview

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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

IComponent

QComponent

QPSK Waveform

1

1

-1

1

-1

1

1

-1

-1

-1

1 1 -1 1 -1 1 1 -1

Page 47: 01-Wcdma Ran Overview

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Demodulation

QPSK Constellation Diagram

1 102 3 4 9875 6

QPSK Waveform

1,1

-1,-1

-1,1

1,-1

1 -11 -1 1 -1-11-1 1

-1,1

NRZ Output

Page 48: 01-Wcdma Ran Overview

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WCDMA Modulation

Different modulation methods corresponding to

different transmitting abilities in air interface

HSDPA: QPSK or 16QAMR99/R4: QPSK

Page 49: 01-Wcdma Ran Overview

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Processing Procedure of WCDMA System

SourceCoding

Channel

CodingSpreading Modulation

SourceDecodin

g

ChannelDecodin

g

Despreading

Demodulation

Transmission

Reception

chipmodulated

signalbit symbol

Service

Signal

Radio Channel

Service

Signal

Transmitter

Receiver

Page 50: 01-Wcdma Ran Overview

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Wireless Propagation

ReceivedSignal

TransmittedSignal

Transmission Loss:Path Loss + Multi-path Fading

Time

Amplitude

Page 51: 01-Wcdma Ran Overview

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Propagation of Radio SignalSignal at Transmitter

Signal at Receiver

-40

-35

-30

-25

-20

-15

-10

-5

dB

0

0

dB

m

-20

-15

-10

-5

5

10

15

20

Fading

Page 52: 01-Wcdma Ran Overview

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Fading Categories

Fading Categories

Slow Fading

Fast Fading

Page 53: 01-Wcdma Ran Overview

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Diversity Technique

Diversity technique is used to obtain uncorrelated signals for combining

Reduce the effects of fading Fast fading caused by multi-path

Slow fading caused by shadowing

Improve the reliability of communication

Increase the coverage and capacity

Page 54: 01-Wcdma Ran Overview

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Diversity

Time diversity

Channel coding, Block interleaving

Frequency diversity

The user signal is distributed on the whole bandwidth

frequency spectrum

Space diversity

Polarization diversity

Page 55: 01-Wcdma Ran Overview

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Principle of RAKE Receiver

Receive set

Correlator 1

Correlator 2

Correlator 3

Searcher correlator

Calculate the time delay and signal strength

CombinerThe

combined signal

tt

s(t) s(t)

RAKE receiver help to overcome on the multi-path fading and enhance the receive performance of the system

Page 56: 01-Wcdma Ran Overview

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Summary

In this course, we have discussed basic concepts of

WCDMA:

Spreading / Despreading principle

UTRAN Voice Coding

UTRAN Channel Coding

UTRAN Spreading Code

UTRAN Scrambling Code

UTRAN Modulation

UTRAN Transmission/Receiving

Page 57: 01-Wcdma Ran Overview

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