WCDMA RAN Fundamentals.pptx

7/21/2019 WCDMA RAN Fundamentals.pptx

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WCDMA RAN Principle

3G RNP&O


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Upon completion of this course, you

will be able to:

Outline the advantage of CDMA

principle

Characterize code sequence

Outline the fundamentals of RAN


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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 numbercentral frequency5, for mainband:

UL frequency channel number 96129888

DL frequency channel number : 1056210838

Bands Used in WCDMA


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The Core technology of 3G: CDMA

WCDMA

CN: based on MAP and GPRS

RTT: WCDMA

TD-SCDMACN: based on MAP and GPRS

RTT: TD-SCDMA

cdma2000CN: based on ANSI 41 and MIP

RTT: cdma2000

CDMA


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1. 3G Overview

2. CDMA Principle

3. WCDMA Network Architecture and protocol

structure

4. WCDMA Wireless Fundamental


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Power

FDMA

Power

TDMA

Power

CDMA

Multiple Access Technology

Power

TDMA


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Duplex Techniques

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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1. 3G Overview

2. CDMA Principle


structure



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WCDMA Network Archiecture

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


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Network Evolution

3GPP Rel993GPP Rel4

3GPP Rel5

2000 2001 2002

GSM/GPRS CN

WCDMA RTT

IMS

HSDPA 3GPP Rel6

MBMS

HSUPA

2005

CS domain change toNGN

WCDMA RTT


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Network 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

WCDMA LTE (Long term evolution) is introduced

OFDMA is adopted instead of CDMA

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


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Uu Interface protocol structure

L3

C-plane signaling U-plane information

PHY

L2/MAC

L2/RLC

MAC

Duplication avoidance

UuS boundary

L2/BMC

L2/PDCP

RRC

con

trol

RLC

RLC

RLCRLC

RLC

RLC

DCNtGC

U-plane information


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General Protocol Mode for UTRAN Terrestrial Interface

The structure is based on the principle that the layers and planesare logically independent of each other.

Application

Protocol

Data

Stream(s)

ALCAP(s)

Transport

Network

Layer

Physical Layer

Signaling

Bearer(s)

Control Plane User Plane

Transport Network

User Plane

Transport Network

Control Plane

Radio

Network

Layer

Signaling

Bearer(s)

Data

Bearer(s)

Transport Network

User Plane


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General Protocol Mode for UTRANTerrestrial Interface

The structure is based on the principle that the layers and planesare logically independent of each other.

Application

Protocol

Data

Stream(s)

ALCAP(s)

Transport

Network

Layer

Physical Layer

Signaling

Bearer(s)

Control Plane User Plane

Transport Network

User Plane

Transport Network

Control Plane

Radio

Network

Layer

Signaling

Bearer(s)

Data

Bearer(s)

Transport Network

User Plane


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Iu-CS Interface

ALCAP

Control Plane

Transport Network

Control Plane

User planeRadioNetwork

Layer

Transport Network

User PlaneTransport

Network

LayerA B

RANAP

AAL2 PATH

ATM

Physical Layer

SAAL NNI

SCCP

MTP3-B

Iu UP

SAAL NNI

MTP3-B

Transport Network

User Plane


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Iu-CS Interface Protocol (IP)


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Iu-PS Interface Protocol (IP)


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ALCAP

Control Plane

Transport Network

Control Plane

Transport Network

User Plane

Transport

Network

Layer

Transport Network

User Plane

SAAL UNI

Iub FP

SAAL UNI

NCP CCP

Iub Interface

ALCAP

Control Plane

Transport Network

Control Plane

User planeRadio

Network

Layer

Transport Network

User Plane

Transport

Network

Layer

Transport Network

User Plane

NBAP

AAL2 PATH

ATM

Physical Layer

SAAL UNI

Iub FP

SAAL UNI

NCP CCP


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Iub Interface Protocol (ATM)


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Iub Interface Protocol (IP)


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1. 3G Overview

2. CDMA Principle


structure



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Processing Procedure of WCDMA System

Source

Coding

Channel Coding& Interleaving

Spreading Modulation

Source

DecodingChannel Decoding

& DeinterleavingDespreading Demodulation

Transmission

Reception

chipmodulatedsignal

bit symbol

Service

Signal

Radio

Channel

Service

Signal

Receiver


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WCDMA Block Coding - CRC

Block coding is used to detect if thereare any uncorrected errors left after error

correction.

The cyclic redundancy check (CRC) is acommon method of block coding.

Adding the CRC bits is done before the

channel encoding and they are checkedafter the channel decoding.


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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 ConvolutionalCoding

1/3 Convolutional

Coding

1/3 Turbo Coding

Uncoded N bits

Coded 2N+16 bits

Coded 3N+24 bits

Coded 3N+12 bits


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Effect

Interleaving is used to reduce the probability of consecutive bits error

Longer interleaving periods have better data protection with more

delay

WCDMA Interleaving

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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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

UE1c1 1 1 1 1 1 1 1 1UE2c2 1 1 1 1 1 1 1 1

UE1c1 UE2c2 2 0 2 0 2 0 2 0


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Orthogonal Code Usage -Decoding

UE1C1 UE2C2: 2 0 2 0 2 0 20

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 (means1) 4 (means1)

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 (means1) 4 (means1)


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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


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Spectrum Analysis of Spreading &Dispreading

Max allowed interference

Eb/NoRequiremen

t

Ebit

Eb / No = Ec / No PG


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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


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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 differentphysical 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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Scrambling Code

Scrambling code: GOLD sequence. There are 224long 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.

P i S bli C d G


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Primary Scrambling Code Group

Primary

scrambling

codes for

downlink

physical

channels

Group 0

Primaryscrambling code 0

Primaryscrambling code8*63

Primaryscrambling code8*63 +7

512 primary

scrambling

codes

Group 1

Group 63



64 primary

scrambling code

groups

Each group consists of 8

primary scrambling codes


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Code Multiplexing

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

Uplink Transmission on a Cell Level


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Processing Procedure of WCDMASystem

Source

Coding

Channel Coding& Interleaving

Spreading Modulation

Source

DecodingChannel Decoding

& DeinterleavingDespreading Demodulation

Transmission

Reception

chip modulatedsignalbit symbol

Service

Signal

Radio

Channel

Service

Signal

Receiver

Modulation 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


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Modulation Overview

1

t

1 10

1

t-1

NRZ coding

fo

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

Digital Modulation - BPSK


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Demodulation

QPSK Constellation Diagram

NRZ Output

QPSK Waveform

1 1 -1 1 -1-1 1

-1,1

1

-1,1 -1,1

-1,-11,-1

WCDMA Modulation


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WCDMA Modulation

Different modulation methods

corresponding to different transmittingabilities in air interface

HSDPA: QPSK or

16QAM

R99/R4: QPSK


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Wireless Propagation

Received

Signal

TransmittedSignal

Transmission Loss:

Path Loss + Multi-path Fading

Time

Amplitude


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Documents

WCDMA RAN Fundamentals.pptx