02 OWA200003 WCDMA Radio Interface Physical Layer (With Comment) ISSUE 1

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WCDMA Radio InterfacePhysical Layer

ISSUE 1.0

HUAWEI TECHNOLOGIES CO., LTD. Page 1All rights reserved

The physical layer offers data transport services

to higher layers.

The access to these services is through the use

of transport channels via the MAC sub-layer.

The physical layer is expected to perform the

following functions in order to provide the data

transport service, for example Modulation and

spreading/demodulation and despreading, Inner -

loop power control etc.


References TS 25.104 UTRA (BS) FDD Radio Transmission and

Reception

TS 25.201 Physical layer-general description

TS 25.211 Physical channels and mapping of

transport channels onto physical channels (FDD)

TS 25.212 Multiplexing and channel coding (FDD)

TS 25.213 Spreading and modulation (FDD)

TS 25.214 Physical layer procedures (FDD)

TS 25.308 UTRA High Speed Downlink Packet Access(HSDPA); Overall description; Stage 2

TR 25.877 High Speed Downlink Packet Acces (HSDPA) -Iub/Iur Protocol Aspects

TR 25.858 Physical layer aspects of UTRA High SpeedDownlink Packet Access


Upon completion of this course, you will beable to:

Outline radio interface protocolArchitecture

Describe key technology of UMTSphysical layer

Describe UMTS physical layer procedures


Chapter 1 Physical Layer OverviewChapter 1 Physical Layer Overview

Chapter 2 Physical Layer Key TechnologyChapter 2 Physical Layer Key Technology

Chapter 3 Physical Layer Processing ProcedureChapter 3 Physical Layer Processing Procedure

Chapter 4 Physical Layer ProceduresChapter 4 Physical Layer Procedures


UTRAN Protocol Structure

RNS

RNC

RNS

RNC

Core Network

NodeB NodeB NodeB NodeB

Iu Iu

Iur

Iub IubIub Iub


Radio Interface Protocol Structure

L3c

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LogicalChannels

TransportChannels

C-plane signaling U-plane information

PHY

L2/MAC

L1

RLC

DCNtGC

L2/RLC

MAC

RLCRLCRLC

RLCRLC

RLCRLC

Duplication avoidance

UuS boundary

BMC L2/BMC

control

PDCPPDCP L2/PDCP

DCNtGC

RadioBearers

RRC



L3c

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LogicalChannels

TransportChannels


PHY

L2/MAC

L1

RLC

DCNtGC

L2/RLC

MAC

RLCRLCRLC

RLCRLC

RLCRLC


UuS boundary

BMC L2/BMC

control

PDCPPDCP L2/PDCP

DCNtGC

RadioBearers

RRC


Spreading Technology Spreading consists of 2 steps

Channelization operation, which transforms data symbols into chips. Thusincreasing the bandwidth of the signal, The number of chips per datasymbol is called the Spreading FactorSF.The operation is done bymultiplying with OVSF code.

Scrambling operation is applied to the spreading signal .

Data bit

OVSFcode

Scramblingcode

Chips afterspreading


Channelization Code

OVSF code is used as channelization code

The channelization codes are uniquely described as Cch,SF,k, where SF is the

spreading factor of the code and k is the code number, 0 k SF-1.

S F = 1 S F = 2 S F = 4

C c h , 1 , 0 = ( 1 )

C c h , 2 , 0 = ( 1 , 1 )

C c h , 2 , 1 = ( 1 , - 1 )

C c h , 4 , 0 = ( 1 , 1 , 1 , 1 )

C c h , 4 , 1 = ( 1 , 1 , - 1 , - 1 )

C c h , 4 , 2 = ( 1 , - 1 , 1 , - 1 )

C c h , 4 , 3 = ( 1 , - 1 , - 1 , 1 )


Scrambling Code

Scrambling code: GOLD sequence.

Scrambling code period: 10ms ,or 38400 chips.

The code used for scrambling of the uplink DPCCH/DPDCH may be of

either long or short type, There are 224 long and 224 short uplink

scrambling codes. Uplink scrambling codes are assigned by higher

layers.

For downlink physical channels, a total of 218-1 = 262,143 scrambling

codes can be generated. scrambling codes k = 0, 1, , 8191 are used.


Scramblingcodes fordownlinkphysicalchannels

Set 0

Set 1

Set 511

Primaryscrambling code 0

Secondaryscrambling code 1

Secondaryscrambling code 15

Primaryscrambling code

51116

Secondaryscrambling code

51116158192 scrambling

codes512 sets

Primary Scrambling Code

A primary scrambling code and 15 secondary scrambling codes areincluded in a set.


Primary Scrambling Code Group

Primaryscramblingcodes fordownlinkphysicalchannels

Group 0



8*63


63*87512 primary

scrambling codes

Group 1

Group 63


Primary scramblingcode 15

64 primary scramblingcode groups

Each group consists of 8primary scrambling codes



Section 1 Physical ChannelSection 1 Physical Channel Structure and FunctionsStructure and Functions

Section 2 Channel MappingSection 2 Channel Mapping


WCDMA radio interface has three kinds of channels

In terms of protocol layer, the WCDMA radio interface has threechannels: Physical channel, transport channel and logical channel.

Logical channel: Carrying user services directly. According to the typesof the carried services, it is divided into two types: Control channel andservice channel.

Transport channel: It is the interface of radio interface layer 2 andphysical layer, and is the service provided for MAC layer by thephysical layer. According to whether the information transported isdedicated information for a user or common information for all users, itis divided into dedicated channel and common channel.

Physical channel: It is the ultimate embodiment of all kinds ofinformation when they are transmitted on radio interfaces. Each kind ofchannel which uses dedicated carrier frequency, code (spreading codeand scramble) and carrier phase (I or Q) can be regarded as adedicated 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)

Logical Channel


Dedicated Channel (DCH)

-DCH is an uplink or downlink channel

Broadcast channel (BCH)

Forward access channel (FACH)

Paging channel (PCH)

Random access channel (RACH)

High-speed downlink shared channel(HS-DSCH)

Common transportchannel

Dedicated transportchannel

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 spreadingcode) can distinguish the channels.

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

(Downlink DPCH)

Downlink Common Physical ChannelCommon Control Physical Channel

(CCPCH)Synchronization Channel (SCH)Paging Indicator Channel (PICH)Acquisition Indicator Channel (AICH)Common Pilot Channel

(CPICH)High-Speed Packet Downlink Shared

Channel (HS-PDSCH)High-Speed Shared Control Channel (HS-

SCCH)

DownlinkPhysical Channel


Uplink Physical Channel

Uplink Dedicated Physical ChannelUplink 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)

Uplink PhysicalChannel


Function of physical channel

Node B UE

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

P-CPICH-Primary Common Pilot ChannelS-CPICH-Secondary Common Pilot ChannelP-CPICH-Primary Common Pilot ChannelS-CPICH-Secondary Common Pilot Channel

Cell broadcast channels

DPDCH-Dedicated Physical Data ChannelDPDCH-Dedicated Physical Data Channel

DPCCH-Dedicated Physical Control ChannelDPCCH-Dedicated Physical Control Channel

Dedicated channels

Paging channels

PICH-Paging Indicator ChannelPICH-Paging Indicator Channel

S-CCPCH-Secondary Common Control Physical ChannelS-CCPCH-Secondary Common Control Physical Channel

PRACH-Physical Random Access ChannelPRACH-Physical Random Access Channel

AICH-Acquisition Indicator ChannelAICH-Acquisition Indicator Channel

Random access channels

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

HS-SCCH-High Speed Share Control ChannelHS-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


Primary Synchronization Channel (P-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. PSC is transmitted repeatedly in each

time slot.

SSC specifies the scrambling codegroups of the cell.

SSC is chosen from a set of 16different codes of length 256, thereare altogether 64 primary scramblingcode groups.

PrimarySCH

SecondarySCH

Slot #0 Slot #1 Slot #14

acsi,0

pac pac pac

acsi,1 acs

i,14

256 chips2560 chips

One 10 ms SCH radio frame


slot numberScramblingCode 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 16Group 1 1 1 5 16 7 3 14 16 3 10 5 12 14 12 10Group 2 1 2 1 15 5 5 12 16 6 11 2 16 11 15 12Group 3 1 2 3 1 8 6 5 2 5 8 4 4 6 3 7Group 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 11Group 62 9 11 12 15 12 9 13 13 11 14 10 16 15 14 16Group 63 9 12 10 15 13 14 9 14 15 11 11 13 12 16 10

Secondary Synchronization Channel (S-SCH)

..

2560 chips

acp

Slot # ?

P-SCH acp

Slot #?

16 6S-SCH

acp

Slot #?

11 Group 2Slot 7, 8, 9256 chips


Common Pilot Channel(CPICH) Common Pilot Channel (CPICH)

Carries pre-defined sequence.

Fixed rate 30Kbps SF=256 Primary CPICH

Uses the fixed channel code -- Cch,256,0 Scrambled by the primary scrambling code Only one CPICH per cell Broadcast over the entire cell The P-CPICH is a phase reference for SCH, Primary CCPCH, AICH, PICH.

By default, it is also a phase reference for downlink DPCH.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) Fixed rate, fixed OVSF code30kbpsCch,256,1 Carry BCH transport channel The PCCPCH is not transmitted during the first 256 chips of each time slot. Only data part STTD transmit diversity may be used

PCCPCH Data18 bits

Slot #0

1 radio frame: T f = 10 ms

Slot #1 Slot #i

256 chips

Slot #14

T slot = 2560 chips,20 bits

SCH


Paging Indicator Channel (PICH) PICH is a fixed-rate (SF=256) physical channel used to carry the Paging Indicators (PI). Frame structure of PICH: one frame of length 10ms consists of 300 bits of which 288 bits

are used to carry paging indicators and the remaining 12 bits are not defined. N paging indicators {PI0, , PIN-1} in each PICH frame, N=18, 36, 72, or 144. If a paging indicator in a certain frame is set to 1, it indicates that UEs associated with

this paging indicator should read the corresponding frame of the associated S-CCPCH.

One radio frame (10 ms)

b1b0

288 bits for paging indication 12 bits (undefined)

b287 b288 b299


Secondary Common Control Physical Channel (SCCPCH) Carry FACH and PCH. Two kinds of SCCPCH: with or without

TFCI. UTRAN decides if a TFCI shouldbe transmitted, UE must support TFCI.

Possible rates are the same as that ofdownlink DPCH

SF =256 - 4. FACH and PCH can be mapped to the

same or separate SCCPCHs. Ifmapped to the same S-CCPCH, theycan be mapped to the same fame.

DataN bits

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

1 radio frame: T f = 10 ms

T slot = 2560 chips,

DataPilot

N bitsPilotN bitsTFCITFCI

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


Physical Random Access Channel (PRACH) The random-access transmission data consists of two parts:

One or several preambleseach preamble is of length 4096chips and consistsof 256 repetitions of a signature whose length is 16 chips16 availablesignatures totally

10 or 20ms message part Which signature is available and the length of message part are determined by

higher layer

Message partPreamble

4096 chips10 ms (one radio frame)

Preamble Preamble

Message partPreamble

4096 chips 20 ms (two radio frames)

Preamble Preamble


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


PRACH Message Structure

PilotN bits

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

Message part radio frame TRACH = 10 ms

Tslot = 2560 chips, 10*2

Pilot

TFCIN bitsTFCI

DataN data bitsData

Control

k bits (k=0..3)


Acquisition Indicator Channel (AICH) Frame structure of AICHtwo frames, 20 msconsists of a repeated

sequence of 15 consecutive AS, each of length 20 symbols(5120 chips).Each time slot consists of two partsan Acquisition-Indicator(AI) and apart of duration 1024chips with no transmission.

Acquisition-Indicator AI have 16 kinds of Signature.

CPICH is the phase reference of AICH.

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)

DPDCH and DPCCH are I/Q code multiplexed within each radio frame

DPDCH carries data generated at Layer 2 and higher layer

DPCCH carries control information generated at Layer 1

Each frame is 10ms and consists of 15 time slots, each time slotconsists of 2560 chips

The spreading factor of DPDCH is from 4 to 256

The spreading factor of DPDCH and DPCCH can be different in thesame Layer 1 connection

Each DPCCH time slot consists of Pilot, TFCIFBITPC


Frame Structure of Uplink DPDCH/DPCCH

PilotNpilot bits

TPCNTPC bits

DataNdatabits


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

1 radio frame: T = 10 msf

DPDCH

DPCCHFBI

NFBI bitsTFCI

NTFCI bits


Downlink Dedicated Physical Channel (DPDCH+DPCCH)

DCH consists of dedicated data and control information.

Control information includesPilotTPCTFCI(optional). The spreading factor of DCH can be from 512 to 4,and can be

changed during connection

DPDCH and DPCCH is time multiplexed.


Frame Structure of Downlink DPCH

One radio frame, Tf = 10 ms


Tslot = 2560 chips, 10*2 k bits (k=0..7)

Data2Ndata2 bits

DPDCH

TFCINTFCI bits

PilotNpilot bits

Data1Ndata1 bits

DPDCH DPCCH DPCCH

TPCNTPC bits


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

Bear service data and layer2 overhead bits mapped from the transportchannel

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

Slot #0 Slot#1 Slot #2

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

DataN Data 1bits

1 subframe: Tf = 2 ms


High-Speed Shared Control Channel (HS-SCCH)

Carries physical layer signalling to a single UE ,such as modulationscheme (1 bit) ,channelization code set (7 bit), transport Block size(6bit),HARQ process number (3bit), redundancy version (3bit), newdata indicator (1bit), Ue identity (16bit)

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

Slot #0 Slot#1 Slot #2

T slot= 2560 chips, 40 bits

DataN Data 1bits

1 subframe: Tf = 2 ms


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

HS-DPCCH carries information to acknowledge downlink transportblocks and feedback information to the system for scheduling and linkadaptation of transport block

CQI and ACK/NACK

Physical Channel ,Uplink, SF=256,power control

S u b f r a m e # 0 S u b f r a m e # i S u b f r a m e # 4

H A R Q - A C K C Q I

O n e r a d i o f r a m e T f = 1 0 m s

O n e H S - D P C C H s u b f r a m e ( 2 m s )

2 T s l o t = 5 1 2 0 c h i p sT s l o t = 2 5 6 0 c h i p s



Section 1 Physical Channel Structure and FunctionsSection 1 Physical Channel Structure and Functions

Section 2 Channel MappingSection 2 Channel Mapping


Mapping Between ChannelsLogical 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



Section 1 Coding and Multiplexing TechnologySection 1 Coding and Multiplexing Technology

Section 2 Spreading TechnologySection 2 Spreading Technology

Section 3 Modulation TechnologySection 3 Modulation Technology


CRC of TB

Error detection is provided on transport blocks through a CyclicRedundancy Check (CRC)

CRC size is informed by higher layer signal

08121624(optional) If no TB are input, no CRC bits should be attached. If TB are

input with TB SIZE=0,CRC bits shall be also added ,but allCRC are zero


TB Concatenation and Code Block Segmentation

All transport blocks in a TTI are serially concatenated .

The maximum size of the code blocks depends on whetherconvolutional coding or turbo coding is used for the TrCH .

Convolutional code: if TBS SIZE>504,segmented to multiple codeblock of the same size.

Turbo code:if TBS SIZE>5114, segmented to multiple code blockof the same size.

No coding:no segmentation

If codes cannot be segmented evenly, fill in 0 bits at thebeginning of the first code block.

If the code block length of Turbo code


Channel coding

The following channel coding schemes can be applied to TrCHs:

Convolutional coding, coding rates 1/3 and 1/2 are defined

Turbo coding, The coding rate of Turbo coder is 1/3

No coding

Usage of coding

BCH, PCH and RACH1/2 Convolutional coding

DCH and FACH1/2 or 1/3 Convolutional coding ,1/3 Turbocoding, no coding


Rate Matching

Rate matching means that bits on a transport channel are repeated orpunctured.

The number of bits on a transport channel can vary between differenttransmission time intervals(TTI). In the downlink the transmission isinterrupted if the number of bits is lower than maximum. When thenumber of bits between different transmission time intervals in uplinkis changed, bits are repeated or punctured to ensure that the total bitrate after TrCH multiplexing is identical to the total channel bit rate ofthe allocated dedicated physical channels.


Interleaving

Function: reduce the influence of fast fading.

Two kinds of interleaving: 1st interleaving and 2nd interleaving

The length of 1st interleaving is TTI of TrCH, 1st interleaving isa inter-frame interleaving

The length of 2nd interleaving is a physical frame, 2ndinterleaving is a intra-frame interleaving.


Radio Frame Segmentation

When the transmission time interval (TTI) is longer than 10 ms, theinput bit sequence is segmented and mapped onto consecutive Firadio frames.

Following radio frame size equalisation in the UL the input bitsequence length is guaranteed to be an integer multiple of Fi.

Following rate matching in the DL the input bit sequence length isguaranteed to be an integer multiple of Fi.

Fi: Number of radio frames in the transmission time interval of TrCHi.


Multiplexing of TrCH

Every 10 ms, one radio frame from each TrCH is delivered to theTrCH multiplexing. These radio frames are serially multiplexed intoa coded composite transport channel (CCTrCH)

The format of CCTrCH is indicated by TFCI

TrCH can have different TTI before multiplexing

2 types of CCTrCH:Common and dedicated

Common CCTrCH should be multiplexed by common TrCH;

Dedicated CCTrCH should be multiplexed by dedicated TrCH

There is only one CCTrCH in uplink and one or several CCTrCH indownlink for one user


Insertion of Discontinuous Transmission (DTX)Indication Bits

In the downlink, DTX is used to fill up the radio frame with bits.

DTX indication bits only indicate when the transmission should beturned off, they are not transmitted.

1st insertion of DTX indication bits

This step of inserting DTX indication bits is used only if thepositions of the TrCHs in the radio frame are fixed

2nd insertion of DTX indication bits

The DTX indication bits inserted in this step shall be placed atthe end of the radio frame.


Physical Channel Segmentation and Mapping

When multiple physical channels are used, one CCTrCH radio framecan be divided into multiple physical frames multicode transmission

Each physical channel of multicode transmission must have thesame SF

DPCCH and DPDCH of uplink physical channel is code multiplexed.

DPCCH and DPDCH of downlink physical channel is timemultiplexed

Uplink physical channel must be fully filled except when cpmpressedmode is used

In downlink, the PhCHs do not need to be completely filled with bitsthat are transmitted over the air. Values correspond to DTXindicators, which are mapped to the DPCCH/DPDCH fields but arenot transmitted over the air.


102040 or 80ms

d

a

t

a

d

a

t

a

d

a

t

a

TrCH-i

dataCRC dataCRC dataCRC

dataCRCdataCRC dataCRCd a t aCBL CBL CBL

0816 or 24bits

Size Z512Ktail Conventional code5120KtailTurbo code

CedBL CedBL CedBLCoded data Channel CodingRate matched data

Rate matched data DTXor

orData before 1st interleavingData after 1st interleaved

Radio frame Radio frame Radio frame

Number of Rado frame 124 or 8

TrCH-1 TrCH-2 TrCH-ICCTrCHTrCH-1 TrCH-2 TrCH-I DTXCCTrCH

Ph-1 Ph-2 Ph-P

10ms

10msPh-1 Ph-2 Ph-P

TPC TFCI pilot

SpreadingScrambling

SpreadingScrambling

SpreadingScrambling

TrCH-i+1

data1 data2 TPC TFCI pilotdata1 data2 TPC TFCI pilotdata1 data2

Transport channel multiplexing structure for downlinkTransport channel multiplexing structure for downlink


Example of Coding and Multiplexing

The number of TrChs 3

Transport block size 81, 103, and 60 bitsCRC 12 bits (attached only to TrCh#1)

Coding CC, coding rate = 1/3 for TrCh#1, 2 coding rate =1/2 for TrCh#3

TTI 20 ms

Transport block size 148 bits

Transport block set size 148 bits

CRC 16 bitsCoding CC, coding rate = 1/3

TTI 40 ms

Parameters for12.2kb/s AMR speech

Parameters for3.4kb/s control channel


Example of Coding and MultiplexingTrC h # 1Transport b lock

C R C attach m en t

C R C

T a i l b i t a t t a c h m e n t

C o n v o l u t i o n a lc o d i n g R = 1 / 3 , 1 / 2

R a t e m a t c h i n g

8 1

8 1

3 0 3

T a i l89 3

3 0 3 + N R M 11 s t i n t e r l e a v i n g

1 2

R a d i o f r a m es e g m e n t a t i o n

# 1 a

T o T r C h M u l t i p l e x i n g

3 0 3 + N R M 1

N R F 1 = ( 3 0 3 + N R M 1 ) / 2

N R F 2 = ( 3 3 3 + N R M 2 ) / 2

N R F 3 = ( 1 3 6 + N R M 3 ) / 2

# 1 b

TrC h # 21 0 3

1 0 3

3 3 3

T a i l81 0 3

3 3 3 + N R M 2

# 2 a

TrC h # 36 0

6 0

1 3 6

T a i l86 0

1 3 6 + N R M 3

# 3 a

1 3 6 + N R M 3

# 3 b

3 3 3 + N R M 2

# 2 bN R F 1 N R F 1 N R F 2 N R F 2 N R F 3 N R F 3


Example of Coding and Multiplexing(3.4kbps)T r a n s p o r t b l o c k

C R C a t t a c h m e n t

C R C

C o n v o l u t i o n a lc o d i n g R = 1 / 3

R a t e m a t c h i n g

1 4 8

1 4 8

5 1 6 * B

T a i l8 * B

( 5 1 6 + N R M ) * B

1 s t i n t e r l e a v i n g

1 6 b i t s

R a d i o f r a m es e g m e n t a t i o n

# 1[ ( 1 2 9 + N R M ) * B + N D I ] /

4

T o T r C h M u l t i p l e x i n g

( 5 1 6 + N R M ) * B + N D I

# 2 # 4

T a i l b i t a t t a c h m e n t

1 6 4 * B

# 3

T r B k c o n c a t i n a t i o n B T r B k s ( B = 0 , 1 )

1 6 4 * B

( 5 1 6 + N R M ) * B + N D I

I n s e r t i o n o f D T Xi n d i c a t i o n *

[ ( 1 2 9 + N R M ) * B + N D I ] /4

[ ( 1 2 9 + N R M ) * B + N D I ] /4

[ ( 1 2 9 + N R M ) * B + N D I ] /4

* I n s e r t i o n o f D T X i n d i c a t i o n i s u s e d o n l y i f t h e p o s i t i o n o f t h e T r C H s i n t h e r a d i o f r a m e i s f i x e d .


Example of Coding and Multiplexing

12.2kbpsdata 3.4kbpsdata

TrCHmultiplexing

30kspsDPCH

2n d i n t e r l e a v i ng

Ph y s i c a l c h a nn e lma p p i n g

# 1# 1a # 1c

1 2 1 5

CFN=4 Ns l o t

Pilot symbol TPC

1 2 1 5

CFN=4 N+1s l o t

1 2 1 5

CFN=4 N+2s l o t

1 2 1 5

CFN=4 N+3s l o t

# 1b # 2# 2a # 2 c# 2b # 3# 1a # 1c# 1b # 4# 2a # 2c# 2b

# 1a # 2a # 1b # 2 b # 1 c # 2 c # 1a # 2a # 1b # 2b # 1c # 2c # 1 # 2 # 3 # 4

5 10 5 10 5 10 5 10

1 2 . 2 kb p s d a t a


Uplink DPCCH/DPDCH Spreading The DPCCH is always spread by code cc = Cch,256,0 When only 1 DPDCH exists,(Cd,1 = Cch,SF,k ) k=SF/4 The code used for scrambling of the uplink DPCCH/DPDCH may be of either long

or short type

I

j

c d , 1 d

S l o n g , n o r S s h o r t , n

I + j Q

D P D C H 1

Q

c d , 3 d

D P D C H 3

c d , 5 d

D P D C H 5

c d , 2 d

D P D C H 2

c d , 4 d

D P D C H 4

c d , 6 d

D P D C H 6

c c c

D P C C H

U p t o 6 D P D C H

f o r o n e u s e r


Uplink PRACH Spreading

Message part is shown in the following figurethe value ofgain factors is the same with DPDCH/DPCCH

jccc

cd d

Sr-msg,n

I+jQ

PRACH messagecontrol part

PRACH messagedata part

Q

I


Downlink Spreading

Downlink physical channel except SCH is first serial-to-parallelconverted , spread by the spreading code, and then scrambled by acomplex-valued scrambling code.

The beginning chip of the scrambling code is aligned with the frameboundary of P-CCPCH.

Each channel have different gain factor

I

D a t a o fp h y s i c a l

c h a n n e le x c e p t

S C H

S

PC c h , S F , m

j

S d l , n

Q

I + j Q S


Downlink Spreading

Different physicalhannel come from point S

G 1

G 2

G P

G S

S - S C H

P - S C H


Uplink Modulation The chip rate is 3.84Mbps In the uplink, the complex-valued chip sequence generated by the

spreading process is QPSK modulated

S

Im{S}

Re{S}

cos(t)

C o m p l e x -v a l u e d

s e q u e n c ea f t e r

s p r e a d i n g

- s i n ( t )

S p l i tr e a l &

i m a gp a r t s

P u l s es h a p i n g



Downlink Modulation The chip rate is 3.84Mbps In the downlink, the complex-valued chip sequence generated by the

spreading process is QPSK modulated

S

Im{S}

Re{S}

cos(t)

C o m p l e x -v a l u e d

s e q u e n c ea f t e r

s p r e a d i n g

- s i n ( t )

S p l i tr e a l &

i m a gp a r t s




Synchronization ProcedureCell Search

Frame synchronization andcode-group identification

Scrambling-codeidentification

UE uses SSC to find framesynchronization and identify thecode group of the cell found inthe first step

UE determines the primaryscrambling code through correlationover the CPICH with all codes withinthe identified group, and then detectsthe P-CCPCH and reads BCHinformation

Slot synchronizationUE uses PSC to acquire slotsynchronization to a cell


Synchronization Procedure Channel Timing Relationship

AICH accessslo ts

SecondarySCH

PrimarySCH

S-CCPCH,k

10 ms

PICH

#0 #1 #2 #3 #14#13#12#11#10#9#8#7#6#5#4

P -CCPCH, (SFN modulo 2) = 0 P -CCPCH, (SFN modulo 2) = 1

Any CPICH

k:th S -CCPCH

PICH for k:th S -CCPCH

n:th DPCH DPCH,n


Random access procedure STARTChoose a RACH sub channel from

available 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 RACHmessage transmitted Set physical status to be Nack

on AICH received

Choose a access slot again

Counter> 0 & Preamble power-maximum allowed power


Random Access ProcedureRACH Physical random access procedure

1. Derive the available uplink access slots, in the next full accessslot set, for the set of available RACH sub-channels within thegiven ASC. Randomly select one access slot among the onespreviously determined. If there is no access slot available in theselected set, randomly select one uplink access slot correspondingto the set of available RACH sub-channels within the given ASCfrom the next access slot set. The random function shall be suchthat each of the allowed selections is chosen with equalprobability

2. Randomly select a signature from the set of available signatureswithin the given ASC.

3. Set the Preamble Retransmission Counter to Preamble_Retrans_ Max


Random Access ProcedureRACH

4. Set the parameter Commanded Preamble Power toPreamble_Initial_Power

5. Transmit a preamble using the selected uplink access slot, signature, andpreamble transmission power.

6. If no positive or negative acquisition indicator (AI +1 nor 1)corresponding to the selected signature is detected in the downlink accessslot corresponding to the selected uplink access slot:

T A: Select the next available access slot in the set of available RACHsub-channels within the given ASC;

T B: select a signature;

T C: Increase the Commanded Preamble Power;

T D: Decrease the Preamble Retransmission Counter by one. If thePreamble Retransmission Counter > 0 then repeat from step 6.Otherwise exit the physical random access procedure.


Random Access ProcedureRACH

7. If a negative acquisition indicator corresponding to the selectedsignature is detected in the downlink access slot corresponding tothe selected uplink access slot, exit the physical random accessprocedure Signature

8. If a positive acquisition indicator corresponding to the selectedsignature is detected , Transmit the random access message threeor four uplink access slots after the uplink access slot of the lasttransmitted preamble

9. exit the physical random access procedure


Transmit diversity ModeApplication of Tx diversity modes on downlink physical channelApplication of Tx diversity modes on downlink physical channel

appliedAICHappliedHS-SCCHappliedappliedHS-PDSCHappliedPICH

appliedappliedappliedDPCHappliedS-CCPCHappliedSCHappliedP-CCPCH

Mode 2Mode 1STTDTSTDClosed loop modeOpen loop modePhysical channel type


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

b0 b1 b2 b3

-b2 b3 b0 -b1

Antenna 1

Antenna 2Channel bits

STTD encoded channel bitsfor antenna 1 and antenna 2.


Transmit Diversity-TSTD

Time switching transmit diversity (TSTD) is used only on SCH chaTime switching transmit diversity (TSTD) is used only on SCH channel.nnel.

Antenna 1

Antenna 2

ac si,0

acp

acsi,1

acp

acsi,14

acp

Slot #0 Slot #1 Slot #14

acsi,2

acp

Slot #2

(Tx OFF) (Tx OFF)(Tx OFF)

(Tx OFF)

(Tx OFF)

(Tx OFF)(Tx OFF)(Tx OFF)


Closed Loop Mode


Transmit DiversityClosed Loop Mode Closed loop mode transmit diversity

Used in DPCH and PDSCH Channel coding, interleaving and spreading are done as in non-

diversity mode. The spread complex valued signal is fed to both TXantenna branches, and weighted with antenna specific weightfactors w1 and w2.

The weight factors are determined by the UE, and signalled to theUTRAN access point (=cell transceiver) using the D-bits of the FBIfield of uplink DPCCH.

The calculation of weight factor is the key point of closed loop Txdiversity.there are two modes with different calculation methods ofweight factorT 1mode 1 uses phase adjustmentthe dedicated pilot

symbols of two antennas are different(orthogonal)

T 2mode 2 uses phase/amplitude adjustment the dedicatedpilot symbols of two antennas are the same.

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02 OWA200003 WCDMA Radio Interface Physical Layer (With Comment) ISSUE 1

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Transcript of 02 OWA200003 WCDMA Radio Interface Physical Layer (With Comment) ISSUE 1