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www.huawei.com Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved. WCDMA RAN Fundamental

01-Owa200002 Wcdma Ran Fundamental Issue1.1

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Page 1: 01-Owa200002 Wcdma Ran Fundamental Issue1.1

www.huawei.com

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

WCDMA RAN Fundamental

Page 2: 01-Owa200002 Wcdma Ran Fundamental Issue1.1

Page2Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

Objectives

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

Describe feature of wireless propagation

Outline the advantage of CDMA principle

Characterize code sequence

Outline the fundamentals of RAN

Page 3: 01-Owa200002 Wcdma Ran Fundamental Issue1.1

Page3Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

Contents

1. 3G Overview

2. CDMA Principle

3. WCDMA Fundamental

Page 4: 01-Owa200002 Wcdma Ran Fundamental Issue1.1

Page4Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

Contents

1. 3G Overview

2. CDMA Principle

3. WCDMA Fundamental

Page 5: 01-Owa200002 Wcdma Ran Fundamental Issue1.1

Page5Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

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 6: 01-Owa200002 Wcdma Ran Fundamental Issue1.1

Page7Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

3G Evolution

Proposal of 3G IMT-2000: the general name of third generation mobile com

munication system The third generation mobile communication was first propo

sed 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 7: 01-Owa200002 Wcdma Ran Fundamental Issue1.1

Page8Copyright © 2008 Huawei Technologies Co., Ltd. All 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: 144kbps Walking environment: 384kbps Indoor environment: 2Mbps

Page 8: 01-Owa200002 Wcdma Ran Fundamental Issue1.1

Page9Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

1850 1900 1950 2000 2050 2100 2150 2200 2250

ITU

Europe

USA MSSPCS

A D B BC D CE F A FE MSSReserveBroadcast auxiliary

2165 MHz1990 MHz

1850 1900 1950 2000 2050 2100 2150

2200 2250

1880 MHz 1980 MHz

UMTSGSM 1800 DECT MSS

1885 MHz 2025 MHz

2010 MHz

IMT 2000

MSSUMTS

Japan MSSIMT 2000MSSIMT 2000PHS

1895

1918

BC

1885

A A’

2170 MHz

IMT 20002110 MHz 2170 MHz

MSS MSS

CDMATDDWLL

FDDWLL

1980

2025MHz

GSM1800

CDMAFDDWLL

1960

1920

1945

China

cellular(1) cellular(2) cellular(2)

1805 MHz

1865

1865

1870

1885

1890

1895

1910

1930

1945

1965

1970

1975

3G Spectrum Allocation

Page 9: 01-Owa200002 Wcdma Ran Fundamental Issue1.1

Page10Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

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 10: 01-Owa200002 Wcdma Ran Fundamental Issue1.1

Page11Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

3G Application Service

Time Delay

BER

background

conversational

streaming

interactive

Page 11: 01-Owa200002 Wcdma Ran Fundamental Issue1.1

Page12Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

WCDMA Protocol Version Evolution

3GPP Rel993GPP Rel4

3GPP Rel5

2000 2001 2002

GSM/GPRS CN

WCDMA RTT

IMSHSDPA 3GPP Rel6

MBMSHSUPA

2005

CS domain change to NGN

WCDMA RTT

Page 12: 01-Owa200002 Wcdma Ran Fundamental Issue1.1

Page13Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

WCDMA System 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

Page 13: 01-Owa200002 Wcdma Ran Fundamental Issue1.1

Page14Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

Contents

1. 3G Overview

2. CDMA Principle

3. WCDMA Fundamental

Page 14: 01-Owa200002 Wcdma Ran Fundamental Issue1.1

Page15Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

Multiple Access and Duplex Technology Multiple Access Technology

Frequency division multiple access (FDMA)

Time division multiple access (TDMA)

Code division multiple access (CDMA)

Duplex Technology

Time division duplex (TDD)

Frequency division duplex (FDD)

Page 15: 01-Owa200002 Wcdma Ran Fundamental Issue1.1

Page16Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

Multiple Access Technology

frequency

time

power

FDMA

frequencytime

power

TDMA

power

time

CDMA

frequency

Page 16: 01-Owa200002 Wcdma Ran Fundamental Issue1.1

Page17Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

Duplex Technology

Time

Frequency

Power

TDD

USER 2

USER 1

DL

ULDL

DL

UL

FDD

Time

Frequency

Power

UL DL

USER 2

USER 1

Page 17: 01-Owa200002 Wcdma Ran Fundamental Issue1.1

Page18Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

Contents

1. 3G Overview

2. CDMA Principle

3. WCDMA Fundamental

Page 18: 01-Owa200002 Wcdma Ran Fundamental Issue1.1

Page19Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

Processing Procedure of WCDMA System

SourceCoding

Channel

CodingSpreading Modulation

SourceDecodin

g

ChannelDecodin

g

Despreading

Demodulation

Transmission

Reception

chip modulated signalbit symbol

Service

Signal

Radio Channel

Service

Signal

Transmitter

Receiver

Page 19: 01-Owa200002 Wcdma Ran Fundamental Issue1.1

Page20Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

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

Page 20: 01-Owa200002 Wcdma Ran Fundamental Issue1.1

Page21Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

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 21: 01-Owa200002 Wcdma Ran Fundamental Issue1.1

Page22Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

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

00100 0 … 0 1 0 … 1 0 0 … 1 0 … 1 1

Inter-column permutation

Output bits

Input bits

Interleaving periods: 10, 20, 40, or 80 ms

Page 22: 01-Owa200002 Wcdma Ran Fundamental Issue1.1

Page23Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

WCDMA Channelization Code

OVSF Code (Orthogonal Variable Spreading Factor)

SF = chip rate / symbol rate High data rates → low SF code

Low data rates → high SF 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 23: 01-Owa200002 Wcdma Ran Fundamental Issue1.1

Page24Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

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 24: 01-Owa200002 Wcdma Ran Fundamental Issue1.1

Page25Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

Purpose of Channelization Code For uplink, Channelization code ( OVSF code ) is used to separate

different physical channels of one connection

For downlink, Channelization code ( OVSF code ) is used to separate different connections in a cell

Radio bearer** SF Radio bearer** SF

Speech 4.75 UL 128 Speech 4.75 DL 256

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

Data 2048 kbps UL 4 Data 2048 kbps DL 8

Speech 12.2 + Data 64 kbps UL 16 Speech 12.2 + Data 64 kbps DL

32

** With 3.4 kbps Signaling

Page 25: 01-Owa200002 Wcdma Ran Fundamental Issue1.1

Page26Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

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 26: 01-Owa200002 Wcdma Ran Fundamental Issue1.1

Page27Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

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 27: 01-Owa200002 Wcdma Ran Fundamental Issue1.1

Page28Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

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 28: 01-Owa200002 Wcdma Ran Fundamental Issue1.1

Page29Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

Spreading and DespreadingDesired signal

Other user’s signal

Desired spreadingsignal

Spreading code

Data after despreading

Other spreading signal

Other signal after integration

1

-1

1

-1

1

-1

8

-8

1-1

8-8

Data after integration

Other signal after despreading

Correlation at a CDMA receiver

Correlation with incorrect code

Page 29: 01-Owa200002 Wcdma Ran Fundamental Issue1.1

Page30Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

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 30: 01-Owa200002 Wcdma Ran Fundamental Issue1.1

Page31Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

Spectrum Analysis of Spreading & Dispreading

Max allowed interference

Eb/No Requirement

Power

Max interference caused by UE

Processing Gain

Ebit

Interference from other UE Echip

Eb / No = Ec / Io ×PG

Page 31: 01-Owa200002 Wcdma Ran Fundamental Issue1.1

Page32Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

Purpose of Scrambling Code

Scrambling code is used to distinguish different

transmitters

For downlink, Scrambling code is used to separate

different cells

For uplink, scrambling code is used to separate

different UE

Page 32: 01-Owa200002 Wcdma Ran Fundamental Issue1.1

Page33Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

Scrambling Code

Scrambling code: GOLD sequence.

There are 224 long uplink scrambling codes which are

used for scrambling of the uplink DPCCH/DPDCH. Uplink

scrambling codes are assigned by higher layers.

For downlink physical channels, 8192 scrambling codes

are used.

Page 33: 01-Owa200002 Wcdma Ran Fundamental Issue1.1

Page34Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

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 34: 01-Owa200002 Wcdma Ran Fundamental Issue1.1

Page35Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

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 35: 01-Owa200002 Wcdma Ran Fundamental Issue1.1

Page36Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

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 36: 01-Owa200002 Wcdma Ran Fundamental Issue1.1

Page37Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

Modulation Review

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 37: 01-Owa200002 Wcdma Ran Fundamental Issue1.1

Page38Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

Modulation Review

NRZ coding

90o

NRZ coding

QPSK

Q(t)

I(t)

fo

±A

±A ±Acos(ot)

±Acos(ot + /2)

1 1 /4

1 -1 7/4

-1 1 3/4

-1 -1 5/4

)cos(2: oAQPSK

Page 38: 01-Owa200002 Wcdma Ran Fundamental Issue1.1

Page39Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

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 39: 01-Owa200002 Wcdma Ran Fundamental Issue1.1

Page40Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

Wireless Propagation

ReceivedSignal

TransmittedSignal

Transmission Loss:Path Loss + Multi-path Fading

Time

Amplitude

Page 40: 01-Owa200002 Wcdma Ran Fundamental Issue1.1

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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

5101520

Fading

Page 41: 01-Owa200002 Wcdma Ran Fundamental Issue1.1

Page42Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

Fading Categories

Fading Categories

Slow Fading

Fast Fading

Page 42: 01-Owa200002 Wcdma Ran Fundamental Issue1.1

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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 43: 01-Owa200002 Wcdma Ran Fundamental Issue1.1

Page44Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

Diversity

Time diversity

Channel coding, Block interleaving

Frequency diversity

The user signal is distributed on the whole bandwidth frequency

spectrum

Space diversity

Receive space diversity

Transmit space diversity

Polarization diversity

Vertical polarization

Horizontal polarization

Page 44: 01-Owa200002 Wcdma Ran Fundamental Issue1.1

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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 45: 01-Owa200002 Wcdma Ran Fundamental Issue1.1

Page46Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

Principle of RAKE Receiver

The RAKE receiver take advantage of multi-path diversity

The RAKE receiver processes the received signal

Identify the time delay positions at which significant energy arrives

Allocate correlation receivers (RAKE fingers) to those peaks

Within each Rake finger, track the fast-changing phase and

amplitude values

Adjust the phase, remove the values originating from fast-fading

Combine the demodulated and phase-adjusted symbols across all

active fingers

Present them to the decoder for further processing

This processing is called Maximal Ratio Combining

Page 46: 01-Owa200002 Wcdma Ran Fundamental Issue1.1

Page47Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.

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 47: 01-Owa200002 Wcdma Ran Fundamental Issue1.1

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