001-WCDMA Radio Interface Physical Layer ISSUE 1

7/31/2019 001-WCDMA Radio Interface Physical Layer ISSUE 1

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WCDMA Radio InterfacePhysical Layer

ISSUE 1.0


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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.


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References

TS 25.104 UTRA (BS) FDD Radio Transmission andReception

TS 25.201 Physical layer-general descriptionTS 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


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Upon completion of this course, you will beable to:

Understand radio interface protocolArchitecture

Understand key technology of UMTSphysical layer

Understand UMTS physical layerprocedures


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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


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UTRAN Protocol Structure

RNS

RNC

RNS

RNC

Core Network

Node B Node B Node B Node B

Iu Iu

Iur

Iub IubIub Iub


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Radio Interface Protocol Structure

L3

c o n t r o

l

c o n t r o

l

c o n t r o

l

c o n t r o

l

LogicalChannels

TransportChannels

C-plane signaling U-plane information

PHY

L2/MAC

L1

RLC

DCNtGC

L2/RLC

MAC

RLCRLC

RLCRLC

RLCRLCRLC

Duplication avoidance

UuS boundary

BMC L2/BMC

control

PDCPPDCP L2/PDCP

DCNtGC

RadioBearers

RRC


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Spreading TechnologySpreading consists of 2 steps

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

Scrambling operation is applied to the spreading signal .

Data bit

OVSFcode

Scramblingcode

Chips afterspreading


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Channelization Code

OVSF code is used as channelization code

The channelization codes are uniquely described as C ch,SF,k , where SF is thespreading factor of the code and k is the code number, 0 k SF-1.

SF = 1 SF = 2 SF = 4

C ch,1,0 = (1)

C ch,2,0 = (1,1)

C ch,2,1 = (1,-1)

C ch,4,0 =(1,1,1,1)

C ch,4,1 = (1,1,-1,-1)

C ch,4,2 = (1,-1,1,-1)

C ch,4,3 = (1,-1,-1,1)


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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 2 24 long and 2 24 short uplink scrambling

codes. Uplink scrambling codes are assigned by

higher layers.

For downlink physical channels, a total of 2 18-1 =

262,143 scrambling codes can be generated.

scrambling codes k = 0, 1, , 8191 are used.


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Scramblingcodes fordownlinkphysicalchannels

Set 0

Set 1

Set 511

Primaryscrambling code 0

Secondaryscrambling code 1

Secondaryscrambling code 15

Primaryscrambling code511 16

Secondaryscrambling code

511 16 15

8192 scramblingcodes

512 sets

Primary Scrambling Code

A primary scrambling code and 15 secondary scrambling codes are

included in a set.


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Primary Scrambling Code Group

Primaryscramblingcodes fordownlinkphysicalchannels

Group 0


Primaryscrambling code8*63

Primaryscrambling code

63*8 7512 primary

scrambling codes

Group 1

Group 63


Primary scramblingcode 15

64 primary scramblingcode groups

Each group consists of 8primary scrambling codes


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Charter 3 Physical layer processing procedureCharter 3 Physical layer processing procedure



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

Section 2 Channel MappingSection 2 Channel Mapping


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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 and

physical 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 of

information 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.


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Control channel

Traffic channel

Dedicated 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


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Dedicated Channel (DCH)

-The Dedicated Channel (DCH) is anuplink 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


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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 orspreading code) can distinguish the channels.

Most channels consist of radio frames and time slots, andeach radio frame consists of 15 time slots.

Two types of physical channel:UL and DL

Physical Channel

Frequency,code,phase


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Downlink Physical Channel

Downlink Dedicated Physical Channel

(Downlink DPCH)

Downlink Common Physical Channel

Common Control Physical Channel(CCPCH)

Synchronization Channel (SCH)

Paging Indicator Channel (PICH)

Acquisition Indicator Channel (AICH)Common Pilot Channel (CPICH)

High-Speed Packet Downlink SharedChannel (HS-PDSCH)

High-Speed Shared Control Channel (HS-SCCH)

DownlinkPhysical Channel


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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)

Uplink PhysicalChannel


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Function of physical channel

Node B UE

P-CCPCH-Primary common control physical channel

SCH- Synchronisation Channel

P-CCPCH-Primary common control physical channel

SCH- 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


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Primary Synchronization Channel (P-SCH)Used for cell searchTwo sub channels: P-SCH and S-SCH.SCH is transmitted at the first 256 chipsof every time slot.PSC is transmitted repeatedly in eachtime slot.

SSC specifies the scrambling codegroups of the cell.SSC is chosen from a set of 16

different codes of length 256, thereare altogether 64 primary scramblingcode groups.

PrimarySCH

SecondarySCH

Slot #0 Slot #1 Slot #14

ac si,0

pac pac pac

ac si,1 ac s

i,14

256 chips2560 chips

One 10 ms SCH radio frame


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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 16

Group 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

ac p

Slot # ?

P-SCH ac p

Slot #?

16 6S-SCH

ac p

Slot #?

11 Group 2Slot 7, 8, 9256 chips


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

Carries pre-defined sequence.

Fixed rate 30Kbps SF=256

Primary CPICH

Uses the fixed channel code--C ch, 256,0Scrambled 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: T r = 10 ms


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Primary Common Control Physical Channel (PCCPCH)Fixed rate , fixed OVSF code 30kbps Cch,256,1Carry BCH transport channelThe PCCPCH is not transmitted during the first 256 chips of each time slot.

Only data partSTTD transmit diversity may be used

PCCPCH Data

18 bits

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

1 radio frame: T f = 10 ms

256 chips

T slot = 2560 chips,20 bits

SCH


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Paging Indicator Channel (PICH)PICH is a fixed-rate(SF=256) physical channel used to carry the Paging Indicators (PI).

PICH is always associated with an S-CCPCH to which a PCH transport channel is mapped.

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 pagingindicator should read the corresponding frame of the associated S-CCPCH.

One radio frame (10 ms)

b 1b 0

288 bits for paging indication 12 bits (undefined)

b 287 b 288 b 299


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Secondary Common Control Physical Channel (SCCPCH)Carry FACH and PCH.

Two kinds of SCCPCH: with or without

TFCI. UTRAN decides if a TFCI should

be transmitted, UE must support TFCI.Possible rates are the same as that of

downlink DPCH

SF =256 - 4.

FACH and PCH can be mapped to the

same or separate SCCPCHs. If

mapped to the same S-CCPCH, theycan be mapped to the same fame.

DataN bits


1 radio frame: T f = 10 ms

T slot = 2560 chips,

DataPilot

N bitsPilotN bitsTFCITFCI

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


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Physical Random Access Channel (PRACH)

The random-access transmission data consistsof two parts:

One or several preambles each preambleis of length 4096chips and consists of 256

repetitions of a signature whose length is

16 chips 16 available signatures totally

10 or 20ms message part

Which signature is available and the lengthof message part are determined by higher

layer


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PRACH Transmission Structure

Message partPreamble

4096 chips10 ms (one radio frame)

Preamble Preamble

Message partPreamble

4096 chips 20 ms (two radio frames)

Preamble Preamble


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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


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PRACH Message Structure

PilotN bits

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

Message part radio frame T RACH = 10 ms

Tslot = 2560 chips, 10*2

Pilot

TFCIN bitsTFCI

DataN

databitsData

Control

k bits (k=0..3)


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Acquisition Indicator Channel (AICH)Frame structure of AICH two frames, 20 ms consists of a repeatedsequence of 15 consecutive AS, each of length 20 symbols(5120 chips).Each time slot consists of two parts an 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

a 1 a 2a 0 a 31 a 32a 30 a 33 a 38 a 39

AI part Unused part

20 ms


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Uplink Dedicated Physical Channel (DPDCH&DPCCH)

DPDCH and DPCCH are I/Q code multiplexed within each radioframe

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 timeslot consists of 2560 chips

The spreading factor of DPDCH is from 4 to 256

The spreading factor of DPDCH and DPCCH can be different in

the same Layer 1 connectionEach DPCCH time slot consists of Pilot, TFCI FBI TPC


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Frame Structure of Uplink DPDCH/DPCCH

PilotNpilot bits

TPCNTPC bits

DataN data bits


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

1 radio frame: Tf = 10 ms

DPDCH

DPCCHFBI

NFBI bitsTFCI

NTFCI bits


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Downlink Dedicated Physical Channel (DPDCH+DPCCH)

DCH consists of dedicated data and control information.

Control information includes Pilot TPC TFCI(optional).The spreading factor of DCH can be from 512 to 4,and can bechanged during connection

DPDCH and DPCCH is time multiplexed.


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Frame Structure of Downlink DPCH

One radio frame, T f = 10 ms


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

Data2Ndata2 bits

DPDCH

TFCINTFCI bits

PilotNpilot bits

Data1Ndata1 bits

DPDCH DPCCH DPCCH

TPCNTPC bits


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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

Slo t #0 Slo t#1 Slot #2

T slot = 2560 ch ip s , M *10*2 k bi ts (k=4 )

D a t a N da ta 1 bits

1 subf ram e: T f = 2 m s


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High-Speed Shared Control Channel (HS-SCCH)

Carries physical layer signalling to a single UE ,such asmodulation 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 physicalchannel used to carry downlink signalling related to HS-DSCH

transmission

S lo t # 0 S l o t # 1 S lo t # 2

T s l o t = 2 5 6 0 c h i p s , 4 0 b i t s

D a t a N d a t a 1 b i t s

1 s u b f r a m e : T f = 2 m s


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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 link

adaptation of transport blockCQI 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


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

Section 2 Channel MappingSection 2 Channel Mapping


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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

S i C Ch l P


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RBS

FACH (control): default =18 (1.8 dB)

Paging channel: default =-0.4 dB

Paging indication ch: default =-7 (-7 dB)

Primary SCH: default =-18 (-1.8 dB)

Secondary SCH: default =-35 (-3.5 dB)

FACH (traffic): default =15 (1.5 dB)

PCPICH: default = 300(30 dBm)

Broadcast Channel: default = -31 (-3.1 dB)

AICH: default = -6 (-6 dB)

HS-SCCH: default =2 (2 dB)

Setting Common Channel Powers


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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


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CRC of TB

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

CRC size is informed by higher layer signal

0 8 12 16 24(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


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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 the

beginning of the first code block.

If the code block length of Turbo code


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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 FACH1/2or1/3 Convolutional coding ,1/3Turbo

coding, no coding


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Rate Matching

Rate matching means that bits on a transport channel arerepeated or punctured.

The number of bits on a transport channel can vary betweendifferent transmission time intervals(TTI). In the downlink thetransmission is interrupted if the number of bits is lower thanmaximum. When the number of bits between differenttransmission time intervals in uplink is changed, bits arerepeated or punctured to ensure that the total bit rate afterTrCH multiplexing is identical to the total channel bit rate of theallocated dedicated physical channels.


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Interleaving

Function reduce the influence of fast fading.

Two kinds of interleaving 1st interleaving and 2ndinterleaving

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

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


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Radio Frame Segmentation

When the transmission time interval (TTI) is longer than 10 ms,

the input bit sequence is segmented and mapped ontoconsecutive Fi radio 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 lengthis guaranteed to be an integer multiple of Fi.

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


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Multiplexing of TrCHEvery 10 ms, one radio frame from each TrCH is delivered tothe TrCH multiplexing. These radio frames are seriallymultiplexed into a 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

TrCHThere is only one CCTrCH in uplink and one or severalCCTrCH in downlink for one user


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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 shouldbe turned 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 placedat the end of the radio frame.


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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 the sameSF

DPCCH and DPDCH of uplink physical channel is code multiplexed.

DPCCH and DPDCH of downlink physical channel is time multiplexed

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 DTX indicators,which are mapped to the DPCCH/DPDCH fields but are nottransmitted over the air.

Transport channel multiplexing structure for downlinkTransport channel multiplexing structure for downlink


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10 20 40 or 80ms

d a

t a

d a

t a

d a

t a

TrCH-i

data CRC data CRC data CRC

data CRC data CRC data CRCd a t aCBL CBL CBL

0 8 16 or 24bits

Size Z

512 K tail Conventional code

5120 K tail Turbo code

CedBL CedBL CedBLCoded data Channel CodingRate matched data

Rate matched data DTXor

orData before 1 st interleavingData after 1 st interleaved

Radio frame Radio frame Radio frame

Number of Rado frame 1 2 4 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


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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


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Example of Coding and Multiplexing TrCh#1Transpor t b lock

C R C a tt ac h m e n t

C R C

Tai l b i t a ttachmen t

Convo lu t i ona lcod ing R= 1 /3 , 1 /2

Ra te m a tch ing

8 1

8 1

3 0 3

Tail89 3

3 0 3 + N RM 1 1 st in ter leaving

1 2

Rad io f r amesegmenta t ion

# 1 a

To TrCh M ult ip lexing

3 0 3 + N RM 1

N RF 1 = ( 3 0 3 + N RM 1 )/ 2

N RF 2 = ( 3 3 3 + N RM 2 )/ 2

N RF 3 = ( 1 3 6 + N RM 3 )/ 2

# 1 b

TrCh#21 0 3

10 3

3 3 3

Tail81 0 3

3 3 3 + N RM 2

# 2 a

TrCh#36 0

6 0

1 3 6

Tail86 0

1 3 6 + N RM 3

# 3 a

1 3 6 + N R M 3

# 3 b

3 3 3 + N RM 2

# 2 b N RF 1 N R F1 N RF 2 N RF 2 N R F3 N RF 3


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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 in a t io 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 io 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 + NR 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 io 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 .


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Example of Coding and Multiplexing12.2 kbps data 3.4 kbps data

TrCHmultiplexing

30 ksps DPC

2nd interleaving

Physical channelmapping

#1#1a #1c

1 2 15

CFN=4Nslot

Pilot symbol TPC

1 2 15

CFN=4N+1slot

1 2 15

CFN=4N+2slot

1 2 15

CFN=4N+3slot

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

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

510 510 510 510

12.2 kbps data


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

Up to 6 DPDCH

for one user


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Uplink PRACH Spreading

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

ccc

cd d

Sr-msg,n

I+jQ

PRACH messagecontrol part

PRACH messagedata part

I


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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

Data of physicalchannelexceptSCH

SP

C ch,SF,m

S dl,n

Q

I+jQ S


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Downlink Spreading

Different physicalannel come from point S

G1

G2

GP

GS

S-SCH

P-SCH


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Uplink ModulationThe chip rate is 3.84Mbps

In the uplink, the complex-valued chip sequence generated by thespreading process is QPSK modulated

S

Im{S}

Re{S}

cos( t)

Complex-valuedsequenceafterspreading

-sin( t)

Splitreal &imagparts

Pulse

shaping

Pulseshaping


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Downlink ModulationThe chip rate is 3.84Mbps

In the downlink, the complex-valued chip sequence generatedby the spreading process is QPSK modulated

S

Im{S}

Re{S}

cos( t)

Complex-valuedsequenceafterspreading

-sin( t)

Splitreal &imagparts

Pulse

shaping

Pulseshaping


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Synchronization ProcedureCell Search

Frame synchronization and

code-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 within

the 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


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AICH accessslots

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

START


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Random access procedureChoose 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


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Random Access ProcedureRACHPhysical 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 ASC

from 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 signatures

within the given ASC.3. Set the Preamble Retransmission Counter to Preamble_ Retrans_ Max


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Random Access ProcedureRACH4. Set the parameter Commanded Preamble Power toPreamble_Initial_Power

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

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

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

B: select a signature;

C: Increase the Commanded Preamble Power;

D: Decrease the Preamble Retransmission Counter by one. Ifthe Preamble Retransmission Counter > 0 then repeat fromstep 6. Otherwise exit the physical random access procedure.


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Random Access ProcedureRACH

7. If a negative acquisition indicator corresponding to theselected signature is detected in the downlink access slotcorresponding to the selected uplink access slot, exit thephysical random access procedure Signature

8. If a positive acquisition indicator corresponding to theselected signature is detected , Transmit the randomaccess message three or four uplink access slots after theuplink access slot of the last transmitted preamble

9. exit the physical random access procedure

Transmit diversity Mode


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Transmit diversity Mode

Application of Tx diversity modes on downlink physical channel Application of Tx diversity modes on downlink physical channel

applied AICH

applied HS-SCCH

appliedapplied HS-PDSCH

applied PICH

appliedappliedapplied DPCH

applied S-CCPCH

appliedSCH

applied P-CCPCH

Mode 2Mode 1STTDTSTDClosed loop modeOpen loop modePhysical channel type


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Transmit Diversity-STTDSpace time block coding based transmit antenna diversity(STTD

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

b0 b 1 b 2 b 3

b 0 b 1 b 2 b3

-b 2 b3 b 0 -b 1

Antenna 1

Antenna 2Channel bits

STTD encoded channel bitsfor antenna 1 and antenna 2.

Transmit Diversity-TSTD


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Transmit Diversity-TSTD

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

Antenna 1

Antenna 2

ac si,0

ac p

ac si,1

ac p

ac si,14

ac p

Slot #0 Slot #1 Slot #14

ac si,2

acp

Slot #2

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

(Tx OFF)

(Tx OFF)

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


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Closed Loop Mode

Transmit Diversity Closed Loop ModeClosed loop mode transmit diversity


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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 factor

1 mode 1 uses phase adjustment the dedicated pilot

symbols of two antennas are different(orthogonal)

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


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001-WCDMA Radio Interface Physical Layer ISSUE 1

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