wcdma principle 20100208 a v1.0

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WCDMA Principle


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


Contents

1. 3G Overview

2. CDMA Principle

3. WCDMA Network Architecture and protocol structure

4. WCDMA Wireless Fundamental

5. Physical Layer Overview

6. Physical Channels

7. Physical Layer Procedure


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


3G Evolution

Proposal of 3G

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

munication system

The third generation mobile communication was first propos

ed 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


3G Spectrum Allocation


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


3G Application Service

Time Delay

Error Ratio

background

conversational

streaming

interactive


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 MIP

RTT: cdma2000


Contents

1. 3G Overview

2. CDMA Principle







Multiple Access and Duplex Technology

Multiple Access Technology

Frequency division multiple access (FDMA)

Time division multiple access (TDMA)

Code division multiple access (CDMA)


Multiple Access Technology

Frequency

Time

Power

FDMA

FrequencyTime

Power

TDMA

Power

Time

CDMA

Frequency


Multiple Access and Duplex Technology

Duplex Technology

Frequency division duplex (FDD)

Time division duplex (TDD)


Duplex Technology

Time

Frequency

Power

TDD

USER 2

USER 1

DL

ULDL

DL

UL

FDD

Time

Frequency

Power

UL DL

USER 2

USER 1


Contents

1. 3G Overview

2. CDMA Principle







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


WCDMA Network 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


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

WCDMA LTE (Long term evolution) is introduced

OFDMA is adopted instead of CDMA

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


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


General Protocol Mode for UTRAN Terrestrial Interface

The structure is based on the principle that the layers and planes are

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)



Iu-CS Interface

ALCAPALCAP

Control Plane

Transport NetworkControl Plane

User planeRadioNetworkLayer


TransportNetworkLayer

A B

RANAP

AAL2 PATH

ATM

Physical Layer

SAAL NNI

SCCP

MTP3-B

Iu UP

SAAL NNI

MTP3-B



Iu-PS Interface

Control Plane User planeRadioNetworkLayer

Transport Network User PlaneTransport

NetworkLayer


C

RANAP

ATM

SAAL NNI

SCCP

MTP3-B

Iu UP

AAL Type 5

IP

UDP

GTP-U

Physical Layer


Iub Interface

ALCAPALCAP

Control Plane






NBAP

AAL2 PATH

ATM

Physical Layer

SAAL UNI

Iub FP

SAAL UNI

NCP CCP


Iur Interface

ALCAPALCAP

Control Plane




A B

RANAP

AAL2 PATH

ATM

Physical Layer

SAAL NNI

SCCP

MTP3-B

Iur Data Stream

SAAL NNI

MTP3-B




Contents

1. 3G Overview

2. CDMA Principle







Processing Procedure of WCDMA System

SourceCoding

Channel Coding& Interleaving Spreading Modulation

SourceDecodin

g

Channel Decoding& Deinterleaving Despreadi

ngDemodulati

on

Transmission

Reception

chip modulated signalbit symbol

Service

Signal

Radio Channel

Service

Signal

Receiver


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_12.20 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



Transmitter

SourceCoding


SourceDecodin

g


ngDemodulati

on

Transmission

Reception


Service

Signal

Radio Channel

Service

Signal

Receiver


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.


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


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 permutatio

n

Output bits

Input bits

Interleaving periods: 20, 40, or 80 ms



SourceCoding


SourceDecodin

g


ngDemodulati

on

Transmission

Reception


Service

Signal

Radio Channel

Service

Signal

Receiver


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


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


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)


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


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


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


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


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)

……


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





Purpose of Channelization Code

Channelization code is used to distinguish different physical ch

annels 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 se

parate different physical channels of one UE


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 UE

s in one carrier


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.


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 co

des

……

……

Group 1

Group 63

Primary scrambling

code 1

Primary scrambling

code 8

64 primary scrambling code group

sEach group consists of 8 primary scrambling

codes


Code Multiplexing

Downlink Transmission on a Cell Level

Scrambling codeScrambling code

Channelization code 1Channelization code 1



User 1 signal

User 2 signal

User 3 signal

NodeB


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



SourceCoding


SourceDecodin

g


ngDemodulati

on

Transmission

Reception


Service

Signal

Radio Channel

Service

Signal

Receiver


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


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


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


Modulation Overview

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


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


WCDMA Modulation

Different modulation methods corresponding to different

transmitting abilities in air interface

HSDPA: QPSK or 16QAMR99/R4: QPSK



SourceCoding

Channel

CodingSpreading Modulation

SourceDecodin

g

ChannelDecodin

g

Despreading

Demodulation

Transmission

Reception


Service

Signal

Radio Channel

Service

Signal

Transmitter

Receiver


Wireless Propagation

ReceivedSignal

TransmittedSignal

Transmission Loss:Path Loss + Multi-path Fading

Time

Amplitude


Propagation of Radio Signal

Signal at Transmitter

Signal at Receiver

-40

-35

-30

-25

-20

-15

-10

-5

dB

0

0

dB

m

-20

-15

-10

-5

5101520

Fading


Fading Categories

Fading Categories

Slow Fading

Fast Fading


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


Diversity

Time diversity

Channel coding, Block interleaving

Frequency diversity

The user signal is distributed on the whole bandwidth

frequency spectrum

Space diversity

Polarization diversity


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


Contents

1. 3G Overview

2. CDMA Principle







UTRAN Network Structure

RNS

RNC

RNS

RNC

Core Network

NodeB NodeB NodeB NodeB

Iu-CS Iu-PS

Iur

Iub IubIub Iub

CN

UTRAN

UEUu

CS PS

Iu-CSIu-PS

CSPS


RAB, RB and RL

RAB

RB

RLNodeB

RNC CNUE

UTRAN


Contents

1. 3G Overview

2. CDMA Principle







WCDMA Radio Interface Channel Definition

Logical Channel = information container

Defined by <What type of information> is transferred

Transport Channel = characteristics of transmission

Described by <How> and with <What characteristics> data is

transmitted over the radio interface

Physical Channel = specification of the information global content

providing the real transmission resource, maybe a frequency , a

specific set of codes and phase


Logical Channel

Control channel

Traffic channelDedicated traffic channel (DTCH)

Common traffic channel (CTCH)

Broadcast control channel (BCCH)

Paging control channel (PCCH)

Dedicate control channel (DCCH)

Common control channel (CCCH)


Transport Channel

Dedicated Channel (DCH)

Broadcast channel (BCH)

Forward access channel (FACH)

Paging channel (PCH)

Random access channel (RACH)

High-speed downlink shared channel (HS-DSCH)

Common transport channel

Dedicated transport channel


Physical Channel

A physical channel is defined by a specific carrier frequency, code

(scrambling code, spreading code) and relative phase.

In UMTS system, the different code (scrambling code or spreading

code) can distinguish the channels.

Most channels consist of radio frames and time slots, and each radio

frame consists of 15 time slots.

Two types of physical channel: UL and DL

Physical Channel

Frequency, Code, Phase


Downlink Physical Channel

Downlink Dedicated Physical Channel (DL DPCH)

Downlink Common Physical Channel

Primary Common Control Physical Channel (P-CCPCH)

Secondary Common Control Physical Channel (S-CCPCH)

Synchronization Channel (SCH)

Paging Indicator Channel (PICH)

Acquisition Indicator Channel (AICH)

Common Pilot Channel (CPICH)

High-Speed Physical Downlink Shared Channel (HS-PDSCH)

High-Speed Shared Control Channel (HS-SCCH)


Uplink Physical Channel

Uplink Dedicated Physical Channel

Uplink Dedicated Physical Data Channel (Uplink DPDCH)

Uplink Dedicated Physical Control Channel (Uplink DPCCH)

High-Speed Dedicated Physical Channel (HS-DPCCH)

Uplink Common Physical Channel

Physical Random Access Channel (PRACH)


Function of Physical Channel

NodeB UE

P-CCPCH-Primary Common Control Physical ChannelP-CCPCH-Primary Common Control Physical Channel

P-CPICH--Primary Common Pilot ChannelSCH--Synchronisation ChannelP-CPICH--Primary Common Pilot ChannelSCH--Synchronisation Channel

Cell Search Channels

DPDCH--Dedicated Physical Data ChannelDPDCH--Dedicated Physical Data Channel

DPCCH--Dedicated Physical Control ChannelDPCCH--Dedicated Physical Control Channel

Dedicated Channels

Paging ChannelsPICH--Paging Indicator ChannelPICH--Paging Indicator ChannelSCCPCH--Secondary Common Control Physical ChannelSCCPCH--Secondary Common Control Physical Channel

PRACH--Physical Random Access ChannelPRACH--Physical Random Access Channel

AICH--Acquisition Indicator ChannelAICH--Acquisition Indicator ChannelRandom Access Channels

HS-DPCCH--High Speed Dedicated Physical Control ChannelHS-DPCCH--High Speed Dedicated Physical Control Channel

HS-SCCH--High Speed Share Control Channel HS-SCCH--High Speed Share Control Channel HS-PDSCH--High Speed Physical Downlink Share ChannelHS-PDSCH--High Speed Physical Downlink Share Channel

High Speed Downlink Share Channels


Synchronization Channels (P-SCH & S-SCH)

Used for cell search

Two sub channels: P-SCH and S-SCH

SCH is transmitted at the first 256 chips of

every time slot

Primary synchronization code is transmitted

repeatedly in each time slot

Secondary synchronization code specifies the

scrambling code groups of the cell

Primary SCH

Secondary SCH

Slot #0 Slot #1 Slot #14

acsi,0

pac pac pac

acsi,1 acs

i,14

256 chips

2560 chipsOne 10 ms SCH radio frame


Secondary Synchronization Channel (S-SCH)

slot number Scrambling Code Group #0 #1 #2 #3 #4 #5 #6 #7 #8 #9 #10 #11 #12 #13 #14

Group 0 1 1 2 8 9 10 15 8 10 16 2 7 15 7 16

Group 1 1 1 5 16 7 3 14 16 3 10 5 12 14 12 10

Group 2 1 2 1 15 5 5 12 16 6 11 2 16 11 15 12

Group 3 1 2 3 1 8 6 5 2 5 8 4 4 6 3 7

Group 4 1 2 16 6 6 11 15 5 12 1 15 12 16 11 2

…

Group 61 9 10 13 10 11 15 15 9 16 12 14 13 16 14 11

Group 62 9 11 12 15 12 9 13 13 11 14 10 16 15 14 16

Group 63 9 12 10 15 13 14 9 14 15 11 11 13 12 16 10

……..acp

Slot # ?

P-SCH acp

Slot #?

16 6S-SCH

acp

Slot #?

11 Group 2Slot 7, 8, 9

256 chips


Primary Common Pilot Channel (PCPICH)

Primary PCPICH

Carrying pre-defined sequence

Fixed channel code: Cch, 256, 0, Fixed rate 30Kbps

Scrambled by the primary scrambling code

Broadcast over the entire cell

A phase reference for SCH, Primary CCPCH, AICH, PICH and dow

nlink DPCH, Only one PCPICH per cell

Pre-defined symbol sequence

Slot #0 Slot #1 Slot # i Slot #14

Tslot = 2560 chips , 20 bits

1 radio frame: Tr = 10 ms


Primary Common Control Physical Channel (PCCPCH)

Carrying BCH transport channel

Fixed rate, fixed OVSF code (30kbps， Cch, 256, 1)

The PCCPCH is not transmitted during the first 256 chips of each time

slot

PCCPCH Data

18 bits

Slot #0

1 radio frame: Tf = 10 ms

Slot #1 Slot #i

256 chips

Slot #14

Tslot = 2560 chips,20 bits

SCH


Paging Indicator Channel (PICH)

Carrying Paging Indicators (PI)

Fixed rate (30kbps), SF = 256

N paging indicators {PI0, …, PIN-1} in each PICH frame, N=18, 36, 72, or

144

One radio frame (10 ms)

b1 b0

288 bits for paging indication

12 bits (undefined)

b287 b288 b299


Secondary Common Control Physical Channel (SCCPCH)

Carrying FACH and PCH, SF = 256 - 4

Pilot: used for demodulation

TFCI: Transport Format Control Indication, used for describe data

format

DataN bits

Slot #0 Slot #1 Slot #i Slot #14


Tslot = 2560 chips,

Data

PilotN bitsPilotN bits

TFCITFCI

20*2k bits (k=0..6)


Physical Random Access Channel (PRACH)

Carrying uplink signaling and data, consist of two parts:

One or several preambles: 16 kinds of available preambles

10 or 20ms message part

Message partPreamble

4096 chips10 ms (one radio frame)

Preamble Preamble

Message partPreamble

4096 chips 20 ms (two radio frames)

Preamble Preamble


PRACH Message Structure

PilotN bits

Slot # 0 Slot # 1 Slot # i Slot # 14

Message part radio frame T = 10 ms

Tslot = 2560 chips, 10*2

Pilot

TFCIN bitsTFCI

DataNdata bitsData

Control

k bits (k=0..3)


PRACH Access Timeslot Structure

#1 #2 #3 #4 #5 #6 #7 #8 #9 #10 #11 #12 #13 #14

5120 chips

radio frame: 10 ms radio frame: 10 ms

Access slot #0 Random Access Transmission

Access slot #1

Access slot #7

Access slot #14

Random Access Transmission

Random Access Transmission

Random Access TransmissionAccess slot #8


Acquisition Indicator Channel (AICH)

Carrying the Acquisition Indicators (AI), SF = 256

There are 16 kinds of Signature to generate AI

AS #14 AS #0 AS #1 AS #i AS #14 AS #0

a1 a2a0 a31 a32a30 a33 a38 a39

AI part Unused part

20 ms


Uplink Dedicated Physical Channel (DPDCH&DPCCH)

Uplink DPDCH and DPCCH are I/Q code division multiplexed

(CDM) within each radio frame

DPDCH carries data generated at Layer 2 and higher layer, the

OVSF code is Cch,SF,SF/4, where SF is from 256 to 4

DPCCH carries control information generated at Layer 1, the

OVSF code is Cch,256,0


Uplink Dedicated Physical Channel (DPDCH&DPCCH)

Frame Structure of Uplink DPDCH/DPCCH

Pilot Npilot bits

TPC NTPC bits

DataNdata bits


Tslot = 2560 chips, 10*2k bits (k=0..6)


DPDCH

DPCCH FBI NFBI bits

TFCI NTFCI bits


Downlink Dedicated Physical Channel (DPDCH+DPCCH)

Downlink DPDCH and DPCCH is time division multiplexing

(TDM).

DPDCH carries data generated at Layer 2 and higher layer

DPCCH carries control information generated at Layer 1

SF of downlink DPCH is from 512 to 4


Downlink Dedicated Physical Channel (DPDCH+DPCCH)

Frame Structure of Downlink DPCH (DPDCH+DPCCH)

One radio frame, Tf = 10 ms


Tslot = 2560 chips, 20*2k bits (k=-1..6)

Data2Ndata2 bits

DPDCH

TFCI NTFCI bits

Pilot Npilot bits

Data1Ndata1 bits

DPDCH DPCCH DPCCH

TPC NTPC bits


High-Speed Physical Downlink Shared Channel (HS-PDSCH)

Bearing service data and layer 2 overhead bits mapped from the

transport channel

SF=16, can be configured several channels to increase data service

Slot #0 Slot#1 Slot #2

Tslot = 2560 chips, M*10*2k bits (k=4)

DataNdata1 bits

1 subframe: Tf = 2 ms


High-Speed Shared Control Channel (HS-SCCH)

Carries physical layer signalling to a single UE ,such as modulation scheme (1 bit) ,channelization code set (7 bit), transport block size (6bit),HARQ process number (3bit), redundancy version (3bit), new data indicator (1bit), UE identity (16bit)

HS-SCCH is a fixed rate (60 kbps, SF=128) downlink physical channel used to carry downlink signalling related to HS-DSCH transmission

Slot #0 Slot#1 Slot #2

Tslot = 2560 chips, 40 bits

DataNdata1 bits

1 subframe: Tf = 2 ms


High-Speed Dedicated Physical Control Channel (HS-DPCCH )

Carrying information to acknowledge downlink transport blocks and

feedback information to the system for scheduling and link adaptation

of transport block

CQI and ACK/NACK

Physical Channel, Uplink, SF=256

Subframe #0 Subframe #i Subframe #n

One HS-DPCCH subframe ( 2ms )

ACK/NACK


CQI

Tslot = 2560 chips 2 Tslot = 5120 chips


Mapping Between Channels

Logical channels Transport channels Physical channels

BCCH BCH P-CCPCH

FACH S-CCPCH

PCCH PCH S-CCPCH

CCCH RACH

PRACH

FACH S-CCPCH

CTCH FACH S-CCPCH

DCCH, DTCH DCH DPDCH

HS-DSCH HS-PDSCH

RACH, FACH PRACH, S-CCPCH


Contents

1. 3G Overview

2. CDMA Principle







Synchronization Procedure - Cell Search

Frame synchronization & Code Group Identification

Scrambling Code Identification

UE uses SSC to find frame synchronization and identify the code group of the cell found in the first step

UE determines the primary scrambling code through correlation over the PCPICH with all codes within the identified group, and then detects the P-CCPCH and reads BCH information。

Slot Synchronization

UE uses PSC to acquire slot synchronization to a cell


Random Access ProcedureSTART

Choose a RACH sub channel fromavailable ones

Get available signatures

Set Preamble Retrans Max

Set Preamble_Initial_Power

Send a preamble

Check the corresponding AI

Increase message part power by p-m based on preamble power

Set physical status to be RACH message transmitted

Set physical status to be Nack on AICH received

Choose a access slot again

Counter> 0 & Preamble power < maximum allowed power

Choose a signature and increase preamble transmit power

Set physical status to be Nack on AICH received

Get negative AI

No AI

Report the physical status to MAC

END

Get positive AI

The counter of preamble retransmit Subtract 1, Commanded preamble power

increased by Power Ramp Step

N

Y

Send the corresponding message part


Transmit Diversity Mode

Application of Tx diversity modes on downlink physical channel

Physical channel type Open loop mode Closed loop mode

TSTD STTD Mode 1 Mode 2

P-CCPCH – applied – –

SCH applied – – –

S-CCPCH – applied – –

DPCH – applied applied applied

PICH – applied – –

HS-PDSCH – applied applied –

HS-SCCH – applied – –

AICH – applied – –


Transmit Diversity - STTD

Space time block coding based transmit antenna diversity

(STTD)

4 consecutive bits b0, b1, b2, b3 using STTD coding

b0 b1 b2 b3 Antenna 1

Antenna 2Channel bits

STTD encoded channel bitsfor antenna 1 and antenna 2.

b0 b1 b2 b3

-b2 b3 b0 -b1


Transmit Diversity - TSTD

Time switching transmit diversity (TSTD) is used only on SCH

channel

Antenna 1

Antenna 2

i,0

i,1

acsi,14

Slot #0 Slot #1 Slot #14

i,2

acp

Slot #2

(Tx OFF)

(Tx OFF)

(Tx OFF)

(Tx OFF)

(Tx OFF)

(Tx OFF)

(Tx OFF)

acp acp

acsacs

acp

acs(Tx OFF)


Closed Loop Mode

Used in DPCH and HS-PDSCH

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