Introductions to WCDMA FDD Mode Physical Layer

Wireless Information Transmission System Lab.

National Sun Yat-sen UniversityInstitute of Communications Engineering

Introductions to WCDMA FDD Mode Physical Layer

2

Table of Contents

Traditional Sequential ASIC Design FlowWCDMA Network ArchitecturePhysical Layer General DescriptionMultiplexing and Channel Coding (MCC)WCDMA Uplink Physical LayerWCDMA Downlink Physical LayerCompressed ModeSite Selection Transmit Diversity

3

References

3GPP Technical Specification (Release 1999, 25 Series)WCDMA for UMTS – Radio Access For Third Generation Mobile Communications-- by Harri Holma and Antti Toskala, Artech House, 2001Wireless Communications - Principles & Practice-- by Theodore S. Rappaport, Prentice Hall, 2nd Edition, Dec. 31, 2001WCDMA Requirements and Practical Design-- by Rudolf Tanner and Jason Woodard, John Wiley & Sons, Ltd, March 2005.

4

Communications Hardware Design Flow

Floating Point Simulation

Fixed Point Simulation

System Specifications

RTL Coding

Function Verification

1. Perfect Receiver2. Synchronization3. Channel Estimation4. Channel Decoding5. De-Interleaving6. Performance should meet

system requirements.

1. Hardware cost limits precision of received signal.

2. Hardware architecture should be considered.

3. Performance is worse than floating point simulation.

1. RTL:Register Transfer Level2. Verilog/VHDL



WCDMA Network Architecture

6

Network Elements in a WCDMA PLMNUu Iu

USIM

ME

Cu

UE

Node B

Node B

Node B

Node B

RNC

RNC

Iub Iur

UTRAN

MSC/VLR GMSC

SGSN GGSN

HLR

Core Network

PLMN, PSTNISDN, … etc.

Internet

ExternalNetworks

•PLMN: Public Land Mobile Network. One PLMN is operated by a single operator.

7

User Equipment (UE)The UE consists of two parts:

The Mobile Equipment (ME) is the radio terminal used for radio communication over the Uu interface.The UMTS Subscriber Identity Module (USIM) is a smartcard that holds the subscriber identity, performs authentication algorithms, and stores authentication and encryption keys and some subscription information that is needed at the terminal.

UTRAN consists of two distinct elements:The Node B converts the data flow between the Iub and Uuinterfaces. It also participates in radio resource management.The Radio Network Controller (RNC) owns and controls the radio resources in its domain (the Node Bs connected to it). RNC is the service access point for all services UTRAN provides the core network (CN).

8

WCDMA System ArchitectureUMTS system utilizes the same well-known architecture that has been used by all main 2nd generation systems.The network elements are grouped into:

The Radio Access Network (RAN, UMTS Terrestrial RAN = UTRAN) that handles all radio-related functionality.The Core Network (CN) which is responsible for switching and routing calls and data connections to external networks.

Both User Equipment (UE) and UTRAN consist of completely new protocols, which is based on the new WCDMA radio technology.The definition of CN is adopted from GSM.

9

HLR (Home Location Register) is a database located in the user’s home system that stores the master copy of the user’s service profile.

The service profile consists of, for example, information on allowed services, forbidden roaming areas, and Supplementary Service information such as status of call forwarding and the call forwarding number.It is created when a new user subscribes to the system.HLR stores the UE location on the level of MSC/VLR and/or SGSN.

Main Elements of the GSM Core Network

10

MSC/VLR (Mobile Services Switching Center / Visitor Location Register) is the switch (MSC) and database (VLR) that serves the UE in its current location for circuit switched services.

The MSC function is used to switch the CS transactions.The VLR function holds a copy of the visiting user’s service profile, as well as more precise information on the UE’slocation within the serving system.


11

GMSC (Gateway MSC) is the switch at the point where UMTS PLMN is connected to external CS networks.

All incoming and outgoing circuit switched connections go through GMSC.

SGSN (Serving GPRS (General Packet Radio Service) Support Node) functionality is similar to that of MSC/VLR, but is typically used for Packet Switched (PS) services.GGSN (Gateway GPRS Support Node) functionality is close to that of GMSC but is in relation to PS services.


12

InterfacesCu Interface: this is the electrical interface between the USIM smartcard and the ME. The interface follows a standard format for smartcards.Uu Interface: this is the WCDMA radio interface, which is the subject of the main part of WCDMA technology. This is also the most important open interface in UMTS.Iu Interface: this connects UTRAN to the CN.Iur Interface: the open Iur interface allows soft handover between RNCs from different manufacturers.Iub Interface: the Iub connects a Node B and an RNC. UMTS is the first commercial mobile telephony system where the Controller-Base Station interface is standardized as a fully open interface.



WCDMA Physical Layer General Description (3G TS 25.201)

14

Establishes the characteristics of the layer-1 transport channels and physical channels in the FDD mode, and specifies:

Transport channelsPhysical channels and their structureRelative timing between different physical

channels in the same link, and relative timing between uplink and downlink;

Mapping of transport channels onto the physical channels.

Physical channels and mapping of transport channels onto physical channels (FDD)

TS 25.211

Describes the contents of the layer 1 documents (TS 25.200 series); where to find information; a general description of layer 1.

Physical Layer –general description

TS 25.201

3GPP RAN Specifications

15

Establishes the characteristics of the spreading and modulation in the FDD mode, and specifies:

Spreading;Generation of channelization and scrambling codes;Generation of random access preamble codes;Generation of synchronization codes;Modulation;

Spreading and Modulation (FDD)

TS 25.213

Describes multiplexing, channel coding, and interleaving in the FDD mode and specifies:

Coding and multiplexing of transport channels;Channel coding alternatives;Coding for layer 1 control information;Different interleavers;Rate matching;Physical channel segmentation and mapping;

Multiplexing and Channel Coding (FDD)

TS 25.212


16

Establishes the characteristics of the physical layer measurements in the FDD mode, and specifies:

The measurements performance by layer 1;Reporting of measurements to higher layers and

network;Handover measurements and idle-mode

measurements.

Physical Layer Measurements (FDD)

TS 25.215

Establishes the characteristics of the physical layer procedures in the FDD mode, and specifies:

Cell search procedures;Power control procedures;Random access procedure.

Physical Layer Procedures (FDD)

TS 25.214


17

General Protocol ArchitectureRadio interface means the Uu point between User Equipment (UE) and network.The radio interface is composed of Layers 1, 2 and 3.

Radio Resource Control (RRC)

Medium Access Control

Transport channels

Physical layer

Con

trol /

Mea

sure

men

ts

Layer 3

Logical channelsLayer 2

Layer 1

18

General Protocol Architecture

The circles between different layer/sub-layers indicate Service Access Points (SAPs).The physical layer offers different Transport channels to MAC.

A transport channel is characterized by how the information is transferred over the radio interface.

MAC offers different Logical channels to the Radio Link Control (RLC) sub-layer of Layer 2.

A logical channel is characterized by the type of information transferred.

19

General Protocol ArchitecturePhysical channels are defined in the physical layer.There are two duplex modes: Frequency Division Duplex (FDD) and Time Division Duplex (TDD).In the FDD mode a physical channel is characterized by the code, frequency and in the uplink the relative phase (I/Q).In the TDD mode the physical channels is also characterized by the timeslot.The physical layer is controlled by RRC.

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Service Provided to Higher LayerThe 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:

1. Macrodiversity distribution/combining and soft handover execution.

2. Error detection on transport channels and indication to higher layers.

3. FEC encoding/decoding of transport channels.4. Multiplexing of transport channels and demultiplexing of

coded composite transport channels (CCTrCHs).

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Service Provided to Higher Layer5. Rate matching of coded transport channels to physical

channels.6. Mapping of coded composite transport channels on physical

channels.7. Power weighting and combining of physical channels.8. Modulation and spreading/demodulation and despreading of

physical channels.9. Frequency and time (chip, bit, slot, frame) synchronisation.10. Radio characteristics measurements including FER, SIR,

Interference Power, etc., and indication to higher layers.11. Inner - loop power control.12. RF processing.

22

Multiple AccessUTRA has two modes, FDD (Frequency Division Duplex) & TDD (Time Division Duplex), for operating with paired and unpaired bands respectively.FDD: A pair of frequency bands which have specified separation shall be assigned for the system.TDD: A duplex method whereby uplink and downlink transmissions are carried over same radio frequency by using synchronised time intervals.

In the TDD, time slots in a physical channel are divided into transmission and reception part.

23

Physical Layer MeasurementsRadio characteristics including FER, SIR, Interference power, etc., are measured and reported to higher layers and network. Such measurements are:

1. Handover measurements for handover within UTRA. Specific features being determined in addition to the relative strength of the cell, for the FDD mode the timing relation between cells for support of asynchronous soft handover.

2. The measurement procedures for preparation for handover to GSM900/GSM1800.

3. The measurement procedures for UE before random access process.

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Transport ChannelsTransport channels are services offered by Layer 1 to the higher layers.A transport channel is defined by how and with what characteristics data is transferred over the air interface.

Two groups of transport channels:Dedicated Transport Channels

Common Transport Channels

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Transport ChannelsDedicated Transport Channels

DCH – Dedicated Channel (only one type)

Common Transport Channels – divided between all or a group of users in a cell (no soft handover, but some of them can have fast power control)

BCH: Broadcast Channel

FACH: Forward Access Channel

PCH: Paging Channel

RACH: Random Access Channel

CPCH: Common Packet Channel

DSCH: DL Shared Channel

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Dedicated Transport ChannelsThere exists only one type of dedicated transport channel, the Dedicated Channel (DCH)The Dedicated Channel (DCH) is a downlink or uplink transport channel.The DCH is transmitted over the entire cell or over only a part of the cell using e.g. beam-forming antennas.DCH carries both the service data, such as speech frames, and higher layer control information, such as handover commands or measurement reports from the terminal.

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Dedicated Transport Channels

The content of the information carried on the DCH is not visible to the physical layer, thus higher layer control information and user data are treated in the same way.The physical layer parameters set by UTRAN may vary between control and data.Possibility of fast rate change (every 10 ms)Support of fast power control.Support of soft handover.

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Common Transport ChannelBroadcast Channel (BCH) -- mandatory

BCH is a downlink transport channel that is used to broadcast system and cell specific information.BCH is always transmitted over the entire cell.The most typical data needed in every network is the available random access codes and access slots in the cell, or the types of transmit diversity.BCH is transmitted with relatively high power.Single transport format – a low and fixed data rate for the UTRA broadcast channel to support low-end terminals.

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Common Transport Channel

Paging Channel (PCH) -- mandatoryPCH is a downlink transport channel.PCH is always transmitted over the entire cell.PCH carries data relevant to the paging procedure, that is, when the network wants to initiate communication with the terminal.The identical paging message can be transmitted in a single cell or in up to a few hundreds of cells, depending on the system configuration.

30

Common Transport ChannelRandom Access Channel (RACH) -- mandatory

RACH is an uplink transport channel.RACH is intended to be used to carry control information from the terminal, such as requests to set up a connection.RACH can also be used to send small amounts of packet data from the terminal to the network.The RACH is always received from the entire cell.The RACH is characterized by a collision risk.RACH is transmitted using open loop power control.

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Common Transport ChannelForward Access Channel (FACH) -- mandatory

FACH is a downlink transport channel.FACH is transmitted over the entire cell or over only a part of the cell using e.g. beam-forming antennas.FACH can carry control information; for example, after a random access message has been received by the base station.FACH can also transmit packet data.FACH does not use fast power control.FACH can be transmitted using slow power control.There can be more than one FACH in a cell.The messages transmitted need to include in-band identification information.

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Common Packet Channel (CPCH) -- optionalCPCH is an uplink transport channel.CPCH is an extension to the RACH channel that is intended to carry packet-based user data.CPCH is associated with a dedicated channel on the downlink which provides power control and CPCH Control Commands (e.g. Emergency Stop) for the uplink CPCH.The CPCH is characterised by initial collision risk and by being transmitted using inner loop power control.CPCH may last several frames.

33


Downlink Shared Channel (DSCH) -- optionalDSCH is a downlink transport channel shared by several UEsto carry dedicated user data and/or control information.The DSCH is always associated with one or several downlink DCH.The DSCH is transmitted over the entire cell or over only a part of the cell using e.g. beam-forming antennas.DSCH supports fast power control as well as variable bit rate on a frame-by-frame basis.

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Transport Channel

YesYesYesYesYesNoSuited for bursty data?

Medium or large data amounts.

Medium or large data amounts.

Small or medium data

amounts.

Small data amounts.

Small data amounts.

Medium or large data amount.

Suited for:

NoNoNoNoNoYesSoft Handover

YesYesYesNoNoYesFast PowerControl

Shared between

users.

Shared between

users.

Fixed codes per cell.



According to maximum bit

rate.

CodeUsage

Uplink, only in TDD.

DownlinkUplinkUplinkDownlinkBothUplink/Downlink

USCHDSCHCPCHRACHFACHDCH

Shared ChannelsCommon ChannelDedicatedChannel

35

Transport Channels

DCH

RACH

CPCH

BCH

FACH

PCH

Physical Channels

Dedicated Physical Data Channel (DPDCH)

Dedicated Physical Control Channel (DPCCH)

Physical Random Access Channel (PRACH)

Physical Common Packet Channel (PCPCH)

Primary Common Control Physical Channel (P-CCPCH)

Secondary Common Control Physical Channel (S-CCPCH)

DSCH Physical Downlink Shared Channel (PDSCH)Common Pilot Channel (CPICH)Synchronization Channel (SCH)

Acquisition Indicator Channel (AICH)

Access Preamble Acquisition Indicator Channel (AP-AICH)

Paging Indicator Channel (PICH)

CPCH Status Indicator Channel (CSICH)

Collision-Detection/Channel-Assignment Indicator Channel (CD/CA-ICH)⎪⎪⎪⎪

⎩

⎪⎪⎪⎪

⎨

⎧

Unmapped

Mapping of Transport Channels onto Physical Channels

36

TFI Transport Block

Transport Block

Transport Ch 1

TFI Transport Block

Transport Block

Transport Ch 2

TFCI Coding & Multiplexing

Physical ControlChannel

Physical DataChannel

TFI Transport Block &Error Indication

Transport Block &Error Indication

Transport Ch 1

TFI Transport Block &Error Indication

Transport Block &Error Indication

Transport Ch 2

TFCI Decoding &Demultiplexing

Physical ControlChannel

Physical DataChannel

Physical Layer

Higher Layer

Interface Between Higher Layers and the Physical Layer

37

Transport Format Indicator (TFI)

The TFI is a label for a specific transport format within a transport format set.It is used in the inter-layer communication between MAC and L1 each time a transport block set is exchanged between the two layers on a transport channel.When the DSCH is associated with a DCH, the TFI of the DSCH also indicates the physical channel (i.e. the channelisation code) of the DSCH that has to be listened to by the UE.

38

This is a representation of the current Transport Format Combination.The TFCI is used in order to inform the receiving side of the currently valid Transport Format Combination, and hence how to decode, de-multiplex and deliver the received data on the appropriate Transport Channels.There is a one-to-one correspondence between a certain value of the TFCI and a certain Transport Format Combination.MAC indicates the TFI to Layer 1 at each delivery of Transport Block Sets on each Transport Channel. Layer 1 then builds the TFCI from the TFIs of all parallel transport channels of the UE, processes the Transport Blocks appropriately and appends the TFCI to the physical control signalling.Through the detection of the TFCI the receiving side is able to identify the Transport Format Combination.

Transport Format Combination Indicator (TFCI)

39

In UTRA, the data generated at higher layers is carried over the air with transport channels, which are mapped in the physical layer to different physical channels.The physical layer is required to support variable bit rate transport channels to offer bandwidth-on-demand services, and to be able to multiplex several services to one connection.The transport channels may have a different number of blocks.Each transport channel is accompanied by the Transport Format Indicator (TFI).

Mapping of Transport Channel to Physical Channel

40

The physical layer combines the TFI information from different transport channels to the Transport Format Combination Indicator (TFCI).TFCI is transmitted in the physical control channel.At any moment, not all the transport channels are necessarily active.One physical control channel and one or more physical data channels form a single Coded Composite Transport Channel (CCTrCh).

Mapping of Transport Channel to Physical Channel



Multiplexing and Channel Coding( 3G TS 25.212 )

42

Table of Contents

Overview of MCCTransport channel related terminologiesUL-MCCDL-MCCSome examples

43

Overview of MCCMCC – multiplexing and channel coding

Encoding data stream from MAC and higher layers to offer transport services over the radio transmission linkMap transport block data into physical channel data

Operations performed in MCCCRC attachmentChannel codingInterleavingRadio frame equalization/segmentationRate matchingTransport channel multiplexingMapping to physical channels

44

Overview of MCC

Multiplexing and channel coding (MCC) isa key procedure in 3GPP PHY to support QoSrequirements from upper layersMCC interfaces with the 3GPP MAC layer by transport channels (TrCHs)Different QoS requirements may assign to different transport channelsTransport channels are processed and multiplexed into one or more physical channels (PhCHs) by MCC

45

UL Multiplexing and Channel Coding

46

DL Multiplexing and Channel Coding

47

Transport blockTransport block setTransport block sizeTransport block set sizeTransmission time interval (TTI)Transport formatTransport format setTransport format combinationTransport format combination set

Transport Channel Related Terminologies

48

Transport blockA basic unit exchanged between L1 and MAC

Transport block setA set of transport block exchanged between L1 and MAC at the same time instance in the same transport channel

Transport block sizeSize of transport block

Transport block set sizeSize of transport block set

Transport block TrCH1Transport block

Transport block

Transport block

Transport block

Transport block


49

Transport formatFormat of definition for the delivery of transport block set during a TTI (transmission time interval)Format contains

Dynamic partTransport block sizeTransport block set size

Static partTransmission time intervalError protection

Channel coding type (1/2,1/3convolutional, turbo,no cc)Rate matching parameter

CRC size (8bit, 12bit, 16bit, 24bit, no CRC)Ex:{320bits, 640bits}, { 10ms, ½ convolutional code, rate matching parameter = 1, 8bits CRC }


50

Transport format setThe set of transport formats associated to a transport channelTransport block set size and transport block size can be different in a transport format setAll other parameters are fixed in a transport format set

Ex:{ 40bits, 40bits } , { 80bits, 80bits }, { 160bits, 160bits }{ 10ms, ½ convolutional code, rate matching parameter = 1, 8bits CRC }


51

Transport format combinationL1 multiplexes several transport channels into one physical channelTransport format is a combination of currently valid transport formats of different transport channel

Examples:DCH1: {20bits, 20bits}, {10ms, ½ convolutional code, rm=2}DCH2: {320bits, 1280bits}, {10ms, turbo code, rm = 3}DCH3: {320bits, 320bits}, {40ms, ½ convolutional code, rm= 1}


52

Transport format combination setA set of transport format combination

Ex:Combination 1

DCH1{20bits, 20bits}, DCH2{320bits, 1280bits} DCH3{320bits,320bits}Combination 2

DCH1{40bits, 40bits}, DCH2{320bits, 1280bits} DCH3{320bits,320bits}Combination 3

DCH1{160bits, 160bits}, DCH2{320bits, 320bits} DCH3{320bits,320bits}Static part

DCH1: {10ms, ½ convolutional code, rm=2}DCH2: {10ms, turbo code, rm = 3}DCH3: {40ms, ½ convolutional code, rm = 1}


53

CRC = 16bitsCC = 1/3

TTI = 40ms

CRC = 12 bitsCC = 1/3

TTI = 20ms

No CRCCC = 1/3

TTI = 20ms

No CRCCC = 1/2

TTI = 20ms

AMR TFCS example

NTRCHa=81 NTRCHb=103 NTRCHc=60

NTRCHa=39

NTRCHa=0

NTRCHb=0

NTRCHb=0

NTRCHc=0

NTRCHc=0

NTRCHd=148

NTRCHd=148

NTRCHd=148

Transport format set aTransport format set b

Transport format set cTransport format set d

Transport formatcombination 1Transport formatcombination 2Transport formatcombination 3


54

TFCS is defined every radio link setupEach TF can change every TTI indicated by higher layerReceiver will be noted via “TFCI” bits in DPCCH

Pilot Npilot bits

TPC NTPC bits

DataNdata bits

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

Tslot = 2560 chips, 10 bits

1 radio frame: Tf = 10 ms

DPDCH

DPCCHFBI

NFBI bitsTFCI

NTFCI bits

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


55

UL-MCCCRC attachmentTrBk concatenation / code block segmentationChannel codingRadio frame equalization1st interleavingRadio frame segmentationRate matchingTrCH multiplexingPhysical channel segmentation2nd interleavingPhysical channel mapping

56

UL-MCCCRC-attachment

For error detectiongCRC24(D) = D24 + D23 + D6 + D5 + D + 1gCRC16(D) = D16 + D12 + D5 + 1gCRC12(D) = D12 + D11 + D3 + D2 + D + 1gCRC8(D) = D8 + D7 + D4 + D3 + D + 1

TrBk

TrBk

57

UL-MCC

TrBk concatenation

Code block segmentationInput block size of channel encoder is limitedconvolutional coding : 504 bit maxturbo coding : 5114 bit maxThe whole input block is segmented into the same smaller size. Filler bits are added to the last block

TrBkTrBk CRC

CRC TrBk CRC TrBk CRC

1498 bits 500 bits 500 bits 498 bits

2 filler bits

58

UL-MCC

Channel codingFor error correction

Turbo-codeHigher error correction capability, long decoding latencyRate = 1/3

Convolutional codeLower error correction capability, short decoding latencyRate = 1/2 or 1/3

59

UL-MCC

Usage of coding scheme and coding rate

No coding1/3Turbo coding

1/3, 1/2CPCH, DCH, DSCH, FACH

RACHPCH

1/2Convolutional codingBCH

Coding rateCoding schemeType of TrCH

60

Convolutional Coding in WCDMA

Output 0G0 = 557 (octal)

InputD D D D D D D D




InputD D D D D D D D


(a) Rate 1/2 convolutional coder

(b) Rate 1/3 convolutional coder

61

Turbo Coder in WCDMA

xk

xk

zk

Turbo codeinternal interleaver

x’k

z’k

D

DDD

DD

Input

OutputInput

Output

x’k

1st constituent encoder

2nd constituent encoder

62

UL-MCC

Concatenation of encoded blocksRadio frame size equalization

301 301Code block

After CC, rate 1/2 602 16 602 16

Concatenation Of encoded blocks 1236

Assume TTI=8, 1236/8 = 154.5,So we add 4 to let it can be divided by 8

1236 4Radio frame sizeequalization

63

UL-MCC

1st interleaving is an inter-frame interleaving schemeInterleaving period is one TTI

10, 20, 40, 80 ms => 1, 2, 4, 8 columns in the interleaving matrix

1st interleaving including three stepswrite input bits into the matrix row by rowperform inter-column permutation based on pre-defined patterns (according to the TTI)read output bits from the matrix column by column

64

UL-MCC

Input bits

STEP 1Write input bitsrow by row

0 2 1 3

STEP 2Inter-columnpermutation

STEP 3Read output bitscolumn by column

1st interleaving:

65

Rate MatchingRate matching performs after radio frame segmentation (per 10ms data)

Nij: number of bits in a radio frame before RM on TrCH iNdata,j: total number of bits that are available for the CCTrCHRMi: rate matching attribute for transport channel iΔNi,j:number of bits that should be repeated/punctured in each radio frame on TrCH i

⎥⎥⎥⎥⎥

⎦

⎥

⎢⎢⎢⎢⎢

⎣

⎢

×

⎟⎟⎠

⎞⎜⎜⎝

⎛×⎟

⎠

⎞⎜⎝

⎛×

=

∑

∑

=

=

I

mjmm

jdata

i

mjmm

ji

NRM

NNRMZ

1,

,1

,

,

INZZN jijijiji , ... 1,i allfor ,,1,, =−−=Δ −

66

Rate Matching

ExampleAssume 3 TrCH

N0 = 30, RM = 10N1 = 100, RM = 12N2 = 20, RM = 13

If Ndata = 180Z1 = floor(300*180/1760) = 30 : Δ= 0Z2 = floor((300+1200)*180/1760) = 153 : ΔN1 = 23Z3 = floor((300+1200+260)*180/1760) = 180 : ΔN2 = 7

If Ndata = 130Z1 = floor(300*130/1760) = 22 : ΔN0 = -8Z2 = floor((300+1200)*130/1760) = 110 : ΔN1 = -12Z3 = floor((300+1200+260)*130/1760) = 130 : ΔN2 = -10

67

Rate MatchingHow could we decide which bits should be punctured/repeated?Determine of eini, eplus, eminus

e = eini

m = 1do while m < Xi (input bit length before RM)

e = e – eminus -- update errorif e <= 0 then -- check if bit m be punctured/ repeated

Repeat or puncture xm

e = e + eplus -- update errorend if

m = m + 1 -- next bit

end do

68

Rate Matching

Example: eini=3, eminus=2, eplus=5 (Puncturing case)

Variable e: 3 1 -1 4 2 0 5 3 1 -1 4 2 0 5 3Input bits: 0 1 0 0 1 0 0 1 1 0Output bits: 0 X 0 X 1 0 X 1 X 0

0100100110 001010RM

+5 +5 +5 +5

69

UL-MCCTrCH multiplexing

Serially multiplex different transport channels into a coded composite transport channel (CCTrCH)

Physical Channel SegmentationIf more than one physical channel (spreading code) is used, physical channel segmentation is used.

2nd interleavingIntra-frame interleavingSimilar with 1st interleaving, but with C2 = 30

Physical channel mappingMap CCTrCH to one or multiple physical channels

70

UL-MCC

TrCH1

TrCH2 TrCH3

TrCH1

TrCH1TTI=2 TTI=2

TrCH2 TrCH2

TTI=4

TrCH3 TrCH3 TrCH3 TrCH3Radio framesegmentation

Rate matching TrCH1 TrCH2 TrCH3TrCH1 TrCH2 TrCH3 TrCH3 TrCH3

TrCH multiplexing TrCH1 TrCH2 TrCH3

CCTrCH2nd interleaving

Physical channel mapping

PhCH

PhCH

c1

c2

71

DL-MCC1. CRC attachment2. TrBk concatenation / code block segmentation3. Channel coding4. Rate matching5. 1st insertion of DTX indication6. 1st interleaving7. Radio frame segmentation8. TrCH multiplexing9. 2nd insertion of DTX indication10. Physical channel segmentation11. 2nd interleaving12. Physical channel mapping

72

Rate Matching

Since DL rate matching is performed before TrCHmultiplexing, the RM does not know TF of other transport channel

TrCH1 TrCH2 TrCH3

TrCH1 TrCH2 TrCH3

TrCH1

PhCH size PhCH size

?

?

?

RM in UL case RM in DL case

73

Rate Matching

2 solutions in DL-RMFixed position

Use the maximum Ni in TFS i for all i as the data size before RMCalculate for ΔNi as in UL case

Flexible positionFind maximum RMi*Ni,j for all combination jCalculate for ΔNi

74

Rate MatchingTFCS example

Combination 1: DCH1{20bits, 20bits}, DCH2{320bits, 1280bits} DCH3{320bits,320bits}Combination 2: DCH1{40bits, 40bits}, DCH2{320bits, 1280bits} DCH3{320bits,320bits}Combination 3: DCH1{160bits, 160bits}, DCH2{320bits, 320bits} DCH3{320bits,320bits}Assume RM1 = RM2 = RM3 = 100 (same importance)

Fixed positionChoose N1=160, N2=1280, N3=320 to calculate for ΔNi

Flexible positionChoose N1=40, N2=1280, N3=320 to calculate for ΔNi (combination 2)

75

Rate Matching

Normal modeFor frames not overlapping with transmission gap

Compressed modeFrames overlapping with transmission gap

Frame structure of type A

Frame structure of type B

Slot # (Nfirst - 1)

TPC

Data1TFCI Data2 PL

Slot # (Nlast + 1)

PL Data1TPC

TFCI Data2 PL

transmission gap

Slot # (Nfirst - 1)

TPC

Data1TFCI Data2 PL

Slot # (Nlast + 1)

PL Data1TPC

TFCI Data2 PL

transmission gap

TPC

76

Rate MatchingCompressed mode by puncturing

Use rate matching algorithm to generate available space for transmission gapWe insert p-bits corresponding to the transmission gap length and will be removed laterUsing slot format A

Compressed mode by reducing the spreading factor by 2Using slot format B (reduce spreading factor by 2) to increase available transmission bits

Compressed mode by higher layer schedulingHigher layer schedule the transmission dataUsing slot format A

77

DTX Insertion

Since the rate matching output is to match the maximum bit number of each TrCH, DTX (discontinuous transmission bits) should be inserted to match the real bit number after TrCH multiplexing

TrCH1 TrCH2 TrCH3

TrCH1 TrCH2 TrCH3

Before RM

After RM

TrCH1 TrCH2 TrCH3TrCH MUX

PhCH size

DTX

78

Physical Channel Mapping

One radio frame, Tf = 10 ms

TPC NTPC bits


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

Data2Ndata2 bits

DPDCHTFCI

NTFCI bitsPilot

Npilot bitsData1

Ndata1 bits

DPDCH DPCCH DPCCH

79

Detail Issues in MCC

Why RM is done after 1st interleaving and radio frame segmentation in UL ?

Although transport format for the individual TrCH changes only once per TTI, combination of TrCHs may be different in each frameRate matching shall be done on a frame-by-frame basis to dynamically assign PhCH resourcesTherefore, radio frame segmentation is performed before rate matching

80

Detail Issues in MCCBut, why RM is done before 1st interleaving and radio frame segmentation in DL ?

PhCH resources are pre-assigned by the upper layers in DLRate matching must be done before 1st interleaving since DTX insertion of fixed position shall be performed after rate matching and before 1st interleavingRate matching parameters are still calculated on a radio frame basis

81

Some ExamplesUL DCH example

UL 12.2 kbps dataUL 64/128/144 kbps packet dataUL 384 kbps packet data

TrCH multiplexing12.2 kbps data + 3.4 kbps data64 kbps data + 3.4 kbps data

DL DCH exampleDL 12.2 kbps dataDL 64/128/144 kbps packet data

TrCH multiplexing12.2 kbps data + 3.4 kbps data

82

UL 12.2 kbps dataT r C h # aT r a n s p o r t b lo c k

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

N T r C H a

N T r C H a

3 * ( N T r C H a + 2 0 )

T a i l8N T r C H a + 1 2

1 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 ip le x in g

T r C h # bN T r C H b

N T r C H b

3 * ( N T r C H b + 8 * N T r C H b / 1 0 3 )

T a i l8 * N T r C H b / 1 0 3N T r C H b

T r C h # cN T r C H c

N T r C H c

2 * ( N T r C H c + 8 * N T r C H c / 6 0 )

T a i l8 * N T r C H c / 6 0N T r C H c

# 1 c # 2 c

R a d i o f r a m ee q u a l i z a t i o n

3 * ( N T r C H a + 2 0 ) 3 * ( N T r C H b + 8 * N T r C H b / 1 0 3 ) 2 * ( N T r C H c + 8 * N T r C H c / 6 0 )1 1

# 2 b # 1 b # 2 b

3 * ( N T r C H a + 2 0 ) + 1 *⎡ N T r C H a / 8 1 ⎤

3 * (N T r C H b + 8 * N T r C H b / 1 0 3 ) + 1 * N T r C

2 * ( N T r C H c + 8 * N T r C H c / 6 0 )

# 1 a

N R F a N R F a N R F b N R F b N R F c N R F c

# 2 b # 1 b # 2 b # 1 c # 2 cN R F a + N R M _ 1 a N R F a + N R M _ 2 b N R F b + N R M _ 1 b N R F b + N R M _ 2 b N R F c + N R M

_ 1 c

N R F c + N R M _

2 c

N R F a = [ 3 * ( N T r C H a + 2 0 )+ 1 * ⎡ N T r C H a /8 1 ⎤ ] /2N R F b = [ 3 * ( N T r C H b + 8 * N T r C H b / 1 0 3 ) + 1 * N T r C H b / 1 0 3 ] /2N R F c = N T r C H c + 8 * N T r C H c / 6 0

* C R C a n d t a i l b i t s f o r T r C H # a i s a t t a c h e d e v e n i f N T r C h a = 0 b i t s s i n c e C R C p a r i t y b i t a t t a c h m e n t f o r 0 b i t t r a n s p o r tb l o c k i s a p p l i e d .

83

UL 64/128/144 kbps dataT r a n s p o r t b lo c k

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

C R C

T u r b o c o d in g R = 1 /3

R a te m a tc h i n g

3 3 6

3 3 6 1 6

3 5 2 * B

1 0 5 6 * B + 1 2 * ⎡ B /9 ⎤


1 0 5 6 * BT a i l b i t a t t a c h m e n t

T a i l1 2 * ⎡ B /9 ⎤1 0 5 6 * B

# 1

T o T r C h M u l t ip l e x in g

T r B k c o n c a t e n a t i o n B T r B k s( B = 0 , 1 , 2 , 4 , 8 , 9 )

# 2

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

( 1 0 5 6 * B + 1 2 * ⎡ B /9 ⎤ ) /2 ( 1 0 5 6 * B + 1 2 * ⎡ B /9 ⎤ ) /2

# 1 # 2( 1 0 5 6 * B + 1 2 * ⎡ B /9 ⎤ ) /2 + N R M 1 ( 1 0 5 6 * B + 1 2 * ⎡ B /9 ⎤ ) /2 + N R M 2

84

UL 384 kbps data T r a n s p o r t b l o c k


C R C

T u r b o c o d i n g R = 1 / 3

3 3 6

3 3 6 1 6

3 5 2 * B

1 0 5 6 * B + 2 4 * ⎡ B / 2 4 ⎤


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

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

T r B k c o n c a t e n a t i o n B T r B k s( B = 0 , 1 , 2 , 4 , 8 , 1 2 , 2 4 )

T a i l

5 2 8 * B

1 7 6 * B 1 7 6 * B

5 2 8 * B 1 2 * ⎡ B / 2 4 ⎤ 5 2 8 * B 1 2 * ⎡ B / 2 4 ⎤

C o d e b l o c k s e g m e n t a t i o n


# 1 # 2

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

( 1 0 5 6 * B + 2 4 * ⎡ B / 2 4 ⎤ ) / 2 ( 1 0 5 6 * B + 2 4 * ⎡ B / 2 4 ⎤ ) / 2

# 1 # 2( 1 0 5 6 * B + 2 4 * ⎡ B / 2 4 ⎤ ) / 2 + N R M 1 ( 1 0 5 6 * B + 2 4 * ⎡ B / 2 4 ⎤ ) / 2 + N R M 2

T a i l

5 2 8 * B

85

12.2 kbps + 3.4 kbps data

12.2 kbps data 3.4 kbps data

TrCHmultiplexing

60 ksps DPDCH

2nd interleaving

Physical channelmapping

#1#1a #1c

CFN=4N CFN=4N+1

#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

600 600 600 600

12.2 kbps data

CFN=4N+2 CFN=4N+3

86

64 kbps + 3.4 kbps data

#1#1 #2 #3 #4

64 kbps data 3.4 kbps data

#2 #3 #4

240 ksps DPDCH

#1 #1 #2 #2 #3 #3 #4 #4

2nd interleaving


CFN=4N CFN=4N+1 CFN=4N+2 CFN=4N+3

TrCHmultiplexing

87

DL 12.2 kbps dataT r C h # aT 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

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


N T r C H a

N T r C H a

3 * ( N T r C H a + 2 0 )

T a i l8N T r C H a + 1 2

3 * ( N T r C H a + 2 0 ) + N R M a


1 2


# 1 a


N R F a = [ 3 * ( N T r C H a + 2 0 ) + N R M a + N D I a ] / 2

N R F b = [ 3 * ( N T r C H b + 8 * N T r C H b / 1 0 3 ) + N R M b + N D I b ] / 2

N R F c = [ 2 * ( N T r C H c + 8 * N T r C H c / 6 0 ) + N R M c + N D I c ] / 2

# 2 a

T r C h # bN T r C H b

N T r C H b

3 * ( N T r C H b + 8 * N T r C H b / 1 0 3 )

T a i l8 * N T r C H b / 1 0 3N T r C H b

3 * ( N T r C H b + 8 *N T r C H b / 1 0 3 ) + N R M b

# 1 b

T r C h # cN T r C H c

N T r C H c

2 * ( N T r C H c + 8 * N T r C H c / 6 0 )

T a i l8 * N T r C H c / 6 0N T r C H c

2 * ( N T r C H c + 8 *N T r C H c / 6 0 ) + N R M c

# 1 c # 2 c# 2 bN R F a N R F a N R F b N R F b N R F c N R F c

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

3 * ( N T r C H a + 2 0 ) + N R M a + N D I 1 3 * ( N T r C H b + 8 *N T r C H b / 1 0 3 ) + N R M b + N D I b

2 * ( N T r C H c + 8 *N T r C H c / 6 0 ) + N R M c + N D I c

3 * ( N T r C H a + 2 0 ) + N R M a + N D I 1 3 * ( N T r C H b + 8 *N T r C H b / 1 0 3 ) + N R M b + N D I b

2 * ( N T r C H c + 8 *N T r C H c / 6 0 ) + N R M c + N D I c

* C R C a n d t a i l b i t s f o r T r C H # a i s a t t a c h e d e v e n i f N T r C h a = 0 b i t s s i n c e C R C p a r i t y b i t a t t a c h m e n t f o r 0 b i t t r a n s p o r tb l o c k i s a p p l i e d .

88

DL 64/128/144 kbps dataT r a n s p o r t b l o c k


C R C

T u r b o c o d i n g R = 1 / 3


3 3 6

3 3 6 1 6

3 5 2 * B

T r B kc o n c a t e n a t i o n

1 0 5 6 * B + 1 2 * ⎡ B / 9 ⎤ + N R M


1 0 5 6 * B + 1 2 * ⎡ B / 9 ⎤ + N R M

1 0 5 6 * BT a i l b i t a t t a c h m e n t

T a i l1 2 * ⎡ B / 9 ⎤1 0 5 6 * B


B T r B k s( B = 0 , 1 , 2 , 4 , 8 , 9 )

# 1( 1 0 5 6 * B + 1 2 * ⎡ B / 9 ⎤ + N R M ) / 2


# 2( 1 0 5 6 * B + 1 2 * ⎡ B / 9 ⎤ + N R M ) / 2

89

12.2 kbps + 3.4 kbps data

12.2 kbps data 3.4 kbps data

TrCHmultiplexing

30 ksps DPCH

2nd interleaving


#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



WCDMA Uplink Physical Layer

91

Table of Contents

Overview

Uplink Physical LayerDedicated Uplink Physical Channels

Uplink Dedicated Physical Data Channel (UL DPDCH)Uplink Dedicated Physical Control Channel (UL DPCCH)

Common Uplink Physical ChannelsPhysical Random Access Channel (PRACH)Physical Common Packet Channel (PCPCH)

Uplink Physical Layer Modulation

92

OverviewConfiguration

Radio frameA radio frame is a processing unit which consists of 15 slots.The length of a radio frame corresponds to 38400 chips.

Time slotA time slot is a unit which consists of fields containing bits.The length of a slot corresponds to 2560 chips.

Spreading Modulation: QPSK.Data Modulation: BPSK.Spreading

Two-level spreading processes

93

OverviewSpreading (cont.)

Channelization operationOVSF codes.Transform every data symbol into a number of chips.Increase the bandwidth of the signal.The number of chips per data symbol is called the Spreading Factor.Data symbols on I- and Q-branches are independently multiplied with an OVSF code.

Scrambling operationLong or short Gold codes.Applied to the spread signals.Randomize the codes

Spread signal is further multiplied by complex-valued scrambling

94

Uplink Physical Channels

Dedicated Uplink Physical ChannelsUplink Dedicated Physical Data Channel (UL DPDCH)Uplink Dedicated Physical Control Channel (UL DPCCH)

Common Uplink Physical ChannelsPhysical Random Access Channel (PRACH)Physical Common Packet Channel (PCPCH)

95

Dedicated Uplink Physical Channels

UL Dedicated Physical Data Channel (UL DPDCH)Carry the DCH transport channel (generated at Layer 2 and above).There may be zero, one, or several uplink DPDCHs on each radio link.

UL Dedicated Physical Control Channel (UL DPCCH)Carry control information generated at Layer 1One and only one UL DPCCH on each radio link.

96

Frame Structure for UL DPDCH/DPCCH

PilotNpilot bits

TPCNTPC bits

DataNdata bits


1 radio frame: Tf = 10 ms = 38400 chips

DPDCH

DPCCHFBI

NFBI bitsTFCI

NTFCI bits

Tslot = 2560 chips,


Ndata= 10*2k bits (k=0,1,…,6)

One Power Control Period

97

UL DPDCHThe parameter k determines the number of bits per uplink DPDCH slot.It is related to the spreading factor SF of the DPDCH as SF = 256/2k.The DPDCH spreading factor ranges from 256 down to 4.

640640960049609606

320320480084804805

1601602400162402404

80801200321201203

40406006460602

202030012830301

101015025615150

NdataBits/ Slot

Bits/ Frame

SFChannel Symbol Rate

(ksps)

Channel Bit Rate (kbps)

Slot Format #i

98

UL DPCCH - Layer 1 Control Information

The spreading factor of the uplink DPCCH is always equal to 256, i.e. there are 10 bits per uplink DPCCH slot.

8-924131015025615155B

10-1423141015025615155A

1522151015025615155

8-1520261015025615154

8-1510271015025615153

8-914231015025615152B

10-1413241015025615152A

1512251015025615152

8-1500281015025615151

8-904241015025615150B

10-1403251015025615150A

1502261015025615150

Transmitted slots per

radio frame

NFBINTFCINTPCNpilotBits/Slot

Bits/Frame

SFChannel Symbol Rate

(ksps)


Slot Format #i

99

UL DPCCH - Layer 1 Control Information

Pilot Bits.Support channel estimation for coherent detection.Frame Synchronization Word (FSW) can be sued to confirm frame synchronizaton.

Transmit Power Control (TPC) command.Inner loop power control commands.

Feedback Information (FBI).Support of close loop transmit diversity.Site Selection Diversity Transmission (SSDT)

Transport-Format Combination Indicator (TFCI) – optionalTFCI informs the receiver about the instantaneous transport format combination of the transport channels.

100

Pilot Bit Patterns with Npilot=3,4,5,6

001010000111011

110001001101011

111111111111111

101001101110000

100011110101100

111111111111111

001010000111011

110001001101011

111111111111111

101001101110000

100011110101100

111111111111111

101001101110000

100011110101100

111111111111111

111111111111111

101001101110000

100011110101100

Slot #0123456789

1011121314

543210432103210210Bit #Npilot = 6Npilot = 5Npilot = 4Npilot = 3

Shadowed column is defined as FSW (Frame Synchronization Word).

101

Pilot Bit Patterns with Npilot=7,8

Shadowed column is defined as FSW (Frame Synchronization Word).

001010000111011

111111111111111

110001001101011

111111111111111

101001101110000

111111111111111

100011110101100

111111111111111

111111111111111

001010000111011

110001001101011

111111111111111

101001101110000

100011110101100

111111111111111

Slot #01234567891011121314

765432106543210Bit #Npilot = 8Npilot = 7

102

FBI BitsThe FBI bits are used to support techniques requiring feedback from the UE to the UTRAN Access Point, including closed loop mode transmit diversity and site selection diversity transmission (SSDT).

The S field is used for SSDT signalling, while the D field is used for closed loop mode transmit diversity signalling.The S field consists of 0, 1, or 2 bits. The D field consists of 0 or 1 bit. Simultaneous use of SSDT power control and closed loop mode transmit diversity requires that the S field consists of 1 bit.

S field D field

NFBI

103

TFCI BitsThere are two types of uplink dedicated physical channels:

those that include TFCI (e.g. for several simultaneous services)those that do not include TFCI (e.g. for fixed-rate services).

It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the uplink.In compressed mode, DPCCH slot formats with TFCI fields are changed.There are two possible compressed slot formats for each normal slot format.

104

TPC Bit Patterns

10

1100

10

NTPC = 2NTPC = 1

Transmitter power control

command

TPC Bit Pattern

105

IΣ

j

c d , 1 β d

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

I+ jQ

D P D C H 1

Q

c d , 3 β d

D P D C H 3

c d , 5 β d

D P D C H 5

c d , 2 β d

D P D C H 2

c d , 4 β d

D P D C H 4

c d , 6 β d

D P D C H 6

c c β c

D P C C H

Σ

Spreading of UL DPCH

106

Spreading of UL DPCHThe binary DPCCH and DPDCHs to be spread are represented by real-valued sequences, i.e. the binary value "0" is mapped to the real value +1, while the binary value "1" is mapped to the real value –1.The DPCCH is spread to the chip rate by the channelization code cc, while the n:th DPDCH called DPDCHn is spread to the chip rate by the channelizationcode cd,n.One DPCCH and up to six parallel DPDCHs can be transmitted simultaneously, i.e. 1 ≤ n ≤ 6.

107

Channelization Codes

Each CDMA channel is distinguished via a unique spreading code.These spreading codes should have low cross-correlation values.In 3GPP W-CDMA, Orthogonal Variable Spreading Factor (OVSF) codes are used.Preserve the orthogonality between a user’s different physical channels.Scrambling is used on top of spreading.

108

Code-tree for Generation of Orthogonal Variable Spreading Factor (OVSF) Codes

SF = 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)

The channelization codes are uniquely described as Cch,SF,k, where SF isthe spreading factor of the code and k is the code number, 0 ≤ k ≤ SF-1.

109


As the chip rate is already achieved in the spreading by the channelization codes, the symbol rate is not affected by the scrambling.Another physical channel may use a certain code in the tree if no other physical channel to be transmitted using the same code three is using a code that is on an underlying branch, i.e. using a higher spreading factor code generated from the intended spreading code to be used.Neither can a smaller spreading factor code on the path to the root of the tree be used.

110


The downlink orthogonal codes within each base station are managed by the radio network controller (RNC) in the network.The definition for the same code tree means that for transmission from a single source, from either a terminal or a base station.One code tree is used with one scrambling code on top of the tree.Different terminals and different base stations may operate their code trees independently of each other.

111

Generation of Channelization Codes1Cch,1,0 =

⎥⎦

⎤⎢⎣

⎡−

=⎥⎦

⎤⎢⎣

⎡−

=⎥⎦

⎤⎢⎣

⎡

1111

0,1,

0,1,

0,1,

0,1,

1,2,

0,2,

ch

ch

ch

ch

ch

ch

CC

CC

CC

( )

( )

( )

( )

( ) ( )

( ) ( ) ⎥⎥⎥⎥⎥⎥⎥⎥⎥

⎦

⎤

⎢⎢⎢⎢⎢⎢⎢⎢⎢

⎣

⎡

−

−

−

=

⎥⎥⎥⎥⎥⎥⎥⎥⎥

⎦

⎤

⎢⎢⎢⎢⎢⎢⎢⎢⎢

⎣

⎡

−−

−−

−++

−++

+

+

+

+

12,2,12,2,

12,2,12,2,

1,2,1,2,

1,2,1,2,

0,2,0,2,

0,2,0,2,

112,12,

212,12,

3,12,

2,12,

1,12,

0,12,

:::

nnchnnch

nnchnnch

nchnch

nchnch

nchnch

nchnch

nnch

nnch

nch

nch

nch

nch

CCCC

CCCCCC

CC

CC

CCCC

112

OVSF Code Allocation for UL DPCH

DPCCH is always spread by cc= Cch,256,0

When there is only one DPDCHDPDCH1 is spread by cd,1= Cch,SF,k (k= SF / 4)

When there are more than one DPDCHAll DPDCHs have SF=4

DPDCHn is spread by the the code cd,n = Cch,4,k

k = 1 if n ∈ {1, 2}, k = 3 if n ∈ {3, 4} and k = 2 if n ∈ {5, 6}

113

Gain of UL DPCHAfter channelization, the real-valued spread signals are weighted by gain factors, βc for DPCCH and βd for all DPDCHs.At every instant in time, at least one of the values βc and βd has the amplitude 1.0. The β-values are quantized into 4 bit words.After the weighting, the stream of real-valued chips on the I- and Q-branches are then summed and treated as a complex-valued stream of chips.This complex-valued signal is then scrambled by the complex-valued scrambling code Sdpch,n.

114

Signaling values for βc and βd

Quantized amplitude ratios βc and βd

15 1.0 14 0.9333 13 0.8666 12 0.8000 11 0.7333 10 0.6667 9 0.6000 8 0.5333 7 0.4667 6 0.4000 5 0.3333 4 0.2667 3 0.2000 2 0.1333 1 0.0667 0 Switch off

Gain of UL DPCH

115

Long scrambling code allocationThe n-th UL long scrambling code

Sdpch,n(i) = Clong,n(i), i = 0, 1, …, 38399

Short scrambling code allocationThe n-th UL short scrambling code

Sdpch,n(i) = Cshort,n(i), i = 0, 1, …, 38399

⎭⎬⎫

⎩⎨⎧

⎥⎦⎥

⎢⎣⎢−+= )2

2()1(1)()( ,2,,1,,icjiciC nlong

inlongnlong

⎭⎬⎫

⎩⎨⎧

⎟⎠⎞

⎜⎝⎛

⎥⎦⎥

⎢⎣⎢−+=

2256mod2)1(1)256mod()( ,2,,1,,

icjiciC nshorti

nshortnshort

Scrambling Codes of UL DPCH

116

Configuration of Uplink Scrambling Sequence Generator

clong,1,n

clong,2,n

MSB LSBx

y

117

Uplink Long Scrambling Codes

Two elementary codes: clong,1,n and clong,2,n.

clong,1,n and clong,2,n are constructed from position wise modulo 2 sum of 38400 chip segments of two binary m-sequences, x and y.

x and y are originated from two generator polynomials of degree 25.x sequence: generator polynomial: X25+X3+1y sequence: generator polynomial: y25+y3+y2+y+1

The sequence clong,2,n is a 16777232 chip shifted version of the sequence clong,1,n.clong,1,n and clong,2,n are Gold codes.

118


For code number, nn=[n23 … n0 ], with n0 being the LSB

Let xn(i) and y(i) denote the i -th chip of the sequence xn and y .

Initial conditionsxn(0)=n0, xn(1)=n1, … , xn(22)=n22, xn(23)=n23, xn(24)=1

y(0)=y(1)= … =y(23)= y(24)=1

119


Recursive formulation, i=0,…, 225-27xn(i+25) =xn(i+3) + xn(i) modulo 2

y(i+25) = y(i+3)+y(i+2) +y(i+1)+y(i) modulo 2

Gold sequence zn

zn(i ) = xn(i ) + y (i ) modulo 2, i = 0, 1, 2, …, 225-2

.22,,1,01)(10)(1

)( 25 −=⎩⎨⎧

=−=+

= …iforizifizif

iZn

nn

120


clong,1,n(i ) = Zn(i ), i = 0, 1, 2, …, 225-2

clong,2,n is a 16777232 chip shifted version of the sequence clong,1,n

clong,2,n(i ) = Zn((i + 16777232) modulo (225 – 1)), i = 0, 1, 2, …, 225-2

⎭⎬⎫

⎩⎨⎧

⎥⎦⎥

⎢⎣⎢−+= )2

2()1(1)()( ,2,,1,,icjiciC nlong

inlongnlong

121

Uplink Short Scrambling Sequence Generator for 255 Chip Sequence

07 4

+ mod n addition

d(i)12356

2

mod 2

07 4b(i)

12356

2

mod 2

+mod 4multiplication

zn(i)

07 4 12356

+mod 4

Mapper

cshort,1,n(i)

a(i)

+ + +

+ ++

+ ++

3 3

3

2

cshort,2,n(i)

122

Uplink Short Scrambling Codes

Two elementary codes: cshort,1,n and cshort,2,n256 chips

GenerationFrom the family of periodically extended S(2) codesThe n:th quaternary S(2) sequence zn(i ), 0 ≤ n ≤ 16777215, is obtained by modulo 4 addition of three sequences

One quaternary sequence a (i )Two binary sequences b (i ) and d (i )

123

Uplink Short Scrambling Codeszn(i ) = a(i ) + 2b(i ) + 2d (i ) modulo 4 (i = 0.. 254)Given a code number n =[n23n22…n0] quaternary sequence a (i ): g0(x)= x8+x5+3x3+x2+2x+1

Initial conditionsa (0) = 2n0 + 1 modulo 4

a (i) = 2ni modulo 4, i = 1, 2, …, 7,

Recursive formulationa (i) = 3a (i-3) + a (i-5) + 3a (i-6) + 2a (i-7) + 3a (i-8) modulo 4, i = 8, 9, …, 254

124


Binary sequence b(i): g1(x)= x8+x7+x5+x+1

Initial conditionsB (i ) = n8+i modulo 2, i = 0, 1, …, 7,

Recursive formulationb (i) = b (i-1) + b (i-3) + b (i-7) + b (i-8) modulo 2, i = 8, 9, …, 254

125


Binary sequence d (i ): g2(x)= x8+x7+x5+x4+1

Initial conditionsd (i ) = n16+i modulo 2, i = 0, 1, …, 7

Recursive formulationd (i ) = d (i-1) + d (i-3) + d (i-4) + d (i-8) modulo 2, i = 8, 9, …, 254

zn(i) = a (i) + 2b (i) + 2d (i) modulo 4 (i = 0.. 254)

126


zn(i) is extended to length 256 chipszn(255) = zn(0)

Mapping

Cshort, n is

zn(i) cshort,1,n(i) cshort,2,n(i)0 +1 +11 -1 +12 -1 -13 +1 -1

⎭⎬⎫

⎩⎨⎧

⎟⎠⎞

⎜⎝⎛

⎥⎦⎥

⎢⎣⎢−+=

2256mod2)1(1)256mod()( ,2,,1,,

icjiciC nshorti

nshortnshort

127

PRACH is used to carry the RACH.The random access transmission is based on a Slotted ALOHA approach with fast acquisition indication.The UE can start the random-access transmission at the beginning of a number of well-defined time intervals, denoted access slots.There are 15 access slots per two frames and they are spaced 5120 chips apart.Information on what access slots are available for random-access transmission is given by higher layers.

Physical Random Access Channel (PRACH)

128

#0 #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 Access Slot Numbers and Their Spacing

129

Message partPreamble

4096 chips10 ms (one radio frame)

Preamble Preamble

Message partPreamble

4096 chips 20 ms (two radio frames)

Preamble Preamble

The random-access transmission consists of one or several preambles of length 4096 chips and amessage of length 10 ms or 20 ms.

Structure of the Random-Access Transmission

130

RACH Preamble Code ConstructionEach preamble is of length 4096 chips and consists of 256 repetitions of a signature of length 16 chips. There are a maximum of 16 available signatures. The random access preamble code Cpre,n, is a complex valued sequence.It is built from a preamble scrambling code Sr-pre,nand a preamble signature Csig,s as follows:

where k=0 corresponds to the chip transmitted first in time.

4095,,2,1,0 ,)()()()

24(

,,,, …=××=+

− kekCkSkCkj

ssignprersnpre

ππ

131

PRACH Preamble Scrambling Code

The scrambling code for the PRACH preamble part is constructed from the long scrambling sequences.There are 8192 PRACH preamble scrambling codes in total.The n:th preamble scrambling code, n = 0, 1, …, 8191, is defined as:

Sr-pre,n(i ) = clong,1,n(i ), i = 0, 1, …, 4095;

132

PRACH Preamble Scrambling Code

The 8192 PRACH preamble scrambling codes are divided into 512 groups with 16 codes in each group.There is a one-to-one correspondence between the group of PRACH preamble scrambling codes in a cell and the primary scrambling code used in the downlink of the cell.The k:th PRACH preamble scrambling code within the cell with downlink primary scrambling code m, k = 0, 1, 2, …, 15 and m = 0, 1, 2, …, 511, is Sr-pre,n(i) as defined above with n = 16×m + k.

133

The preamble signature corresponding to a signature s consists of 256 repetitions of a length 16 signature Ps(n), n=0…15. This is defined as follows:

Csig,s(i) = Ps(i modulo 16), i = 0, 1, …, 4095.

The signature Ps(n) is from the set of 16 Hadamard codes of length 16.

PRACH Preamble Signatures

134

PRACH Preamble Signatures

1-1-11-111-1-111-11-1-11P15(n)

-1-11111-1-111-1-1-1-111P14(n)

-11-111-11-11-11-1-11-11P13(n)

1111-1-1-1-1-1-1-1-11111P12(n)

-111-1-111-11-1-111-1-11P11(n)

11-1-111-1-1-1-111-1-111P10(n)

1-11-11-11-1-11-11-11-11P9(n)

-1-1-1-1-1-1-1-111111111P8(n)

-111-11-1-11-111-11-1-11P7(n)

11-1-1 -1-11111-1 -1-1-111P6(n)

1-11-1-11-111-11-1-11-11P5(n)

-1-1-1-11111-1-1-1-11111P4(n)

1-1-111-1-111-1-111-1-11P3(n)

-1-111-1-111-1-111-1-111P2(n)

-11-11-11-11-11-11-11-11P1(n)

1111111111111111P0(n)

1514131211109876543210

Value of nPreambleSignature

135

PilotNpilotbits

DataNdatabits


Tslot = 2560 chips, 10*2k bits (k=0,1,2,3.)

Message part radio frame TRACH = 10 ms

Data

Control TFCINTFCIbits


Structure of the Random-Access Message Part Radio Frame

136

PRACH Message PartData part

10*2k bits, where k=0,1,2,3.Corresponds to a SF of 256, 128, 64, and 32.

Control partSF=256.

8 known pilot bits to support channel estimation for coherent detection.

2 TFCI bits corresponds to a certain transport format of the current Random-access message.

The message part length can be determined from the sued signature and/or access slot, as configured by higher layers.

137

PRACH Message Part

Slot Format#i

Channel BitRate (kbps)

ChannelSymbol Rate

(ksps)

SF Bits/Frame

Bits/Slot

Ndata

0 15 15 256 150 10 101 30 30 128 300 20 202 60 60 64 600 40 403 120 120 32 1200 80 80

Slot Format#i


ChannelSymbol Rate

(ksps)

SF Bits/Frame

Bits/Slot

Npilot NTFCI

0 15 15 256 150 10 8 2

Random-access message data fields

Random-access message control fields

138

001010000111011

111111111111111

110001001101011

111111111111111

101001101110000

111111111111111

100011110101100

111111111111111

Slot #01234567891011121314

76543210Bit #

Npilot = 8

PRACH Message Part Pilot Bit Pattern

139

jβccc

cd βd

Sr-msg,n

I+jQ

PRACH messagecontrol part

PRACH messagedata part

Q

I

Spreading of PRACH Message Part

Message part OVSF Code AllocationGiven the preamble signature s, 0 ≤ s ≤ 15Control part : cc = Cch,256,m with m = 16s + 15Data part: cd = Cch,SF,m with m = SF x s/16 and SF=32 to 256

140

PRACH Message Part Scrambling CodeThe scrambling code used for the PRACH message part is 10 ms long, and there are 8192 different PRACH scrambling codes defined.The n:th PRACH message part scrambling code, denoted Sr-

msg,n, where n = 0, 1, …, 8191, is based on the long scrambling sequence and is defined as:

Sr-msg,n(i) = Clong,n(i + 4096), i = 0, 1, …, 38399The message part scrambling code has a one-to-one correspondence to the scrambling code used for the preamble part.For one PRACH, the same code number is used for both scrambling codes.

141

PCPCH is used to carry the CPCH.The CPCH transmission is based on DSMA-CD (Digital Sense Multiple Access – Collision Detection) approach with fast acquisition indication.The UE can start transmission at the beginning of a number of well-defined time-intervals.

Physical Common Packet Channel (PCPCH)

142

The PCPCH access transmission consists of:one or several Access Preambles [A-P] of length 4096 chips.one Collision Detection Preamble (CD-P) of length 4096 chipsa DPCCH Power Control Preamble (PC-P) which is either 0 slots or 8 slots in lengtha message of variable length Nx10 ms.

4096 chips

P0P1

Pj Pj

Collision DetectionPreamble

Access Preamble Control Part

Data part

0 or 8 slots N*10 msec

Message Part

Structure of the CPCH Access Transmission

143

CPCH Access Preamble Part

PCPCH access preamble codes Cc-acc,n,s, are complex valued sequences.

The RACH preamble signature sequences are used.The scrambling codes could be either

A different code segment of the Gold code used to form the scrambling code of the RACH preambles orThe same scrambling code in case the signature set is shared.

4095,,2,1,0 ,)()()()

24(

,,,, …=××=+

−− kekCkSkCkj

ssignacccsnaccc

ππ

144

There are 40960 PCPCH access preamble scrambling codes in total.

The n:th PCPCH access preamble scrambling code is defined as:Sc-acc,n (i) = clong,1,n(i), i = 0, 1, …, 4095;

The codes are divided into 512 groups with 80 codes in each group.There is a one-to-one correspondence between the group of PCPCH access preamble scrambling codes in a cell and the primary scrambling code used in the downlink of the cell.

The k:th PCPCH scrambling code within the cell with downlink primary scrambling code m, for k = 0,..., 79 and m = 0, 1, 2, …, 511, is Sc-acc,n as defined above with n=16×m+k for k=0,...,15 and n = 64×m + (k-16)+8192 for k=16,..., 79.

PCPCH Access Preamble Scrambling Code

145

The PCPCH CD preamble codes Cc-cd,n,s are complex valued sequences.

The RACH preamble signature sequences are used.The scrambling code is chosen to be a different code segment of the Gold code used to form the scrambling code for the RACH and CPCH preambles.

4095,,2,1,0 ,)()()()

24(

,,,, …=××=+

−− kekCkSkCkj

ssigncdcsncdc

ππ

CPCH Collision Detection (CD) Preamble Part

146

PCPCH CD Preamble Scrambling CodeThere are 40960 PCPCH-CD preamble scrambling codes in total.

The n:th PCPCH CD access preamble scrambling code, where n = 0 ,..., 40959, is defined as:Sc-cd,n(i) = clong,1,n(i), i = 0, 1, …, 4095;

The 40960 PCPCH scrambling codes are divided into 512 groups with 80 codes in each group.There is a one-to-one correspondence between the group of PCPCH CD preamble scrambling codes in a cell and the primary scrambling code used in the downlink of the cell.

The k:th PCPCH scrambling code within the cell with downlink primary scrambling code m, k = 0,1, …, 79 and m = 0, 1, 2, …, 511, is Sc-cd, n as defined above with n=16×m+k for k = 0,...,15 and n = 64×m + (k-16)+8192 for k=16,...,79.

147

CPCH Power Control Preamble Part

The power control preamble segment is called the CPCH Power Control Preamble (PC-P) part.The slot format for CPCH PC-P part shall be the same as for the CPCH message part.

The scrambling code for the PCPCH power control preamble is the same as for the PCPCH message part.The channelization code the PCPCH power control preamble is the same as the control part of message part.

1225101502561515102261015025615150

NFBINTFCINTPCNpilotBits /Slot

Bits /Slot

SFChannelSymbol Rate

(ksps)


SlotFormat #i

148

Frame Structure for PCPCH

PilotNpilot bits

TPCNTPC bits

DataNdata bits


1 radio frame: Tf = 10 ms = 38400 chips

Data

ControlFBI

NFBI bitsTFCI

NTFCI bits

Tslot = 2560 chips,


Ndata= 10*2k bits (k=0,1,…,6)

149

PCPCH Message PartUp to N_MAX_frames 10ms frames.

N_Max_frames is a higher layer parameter.

Each 10 ms frame is split into 15 slots, each of length 2560 chips.

Each slot consists of two parts:Data part carries higher layer information.

Data part consists of 10*2k bits, where k = 0, 1, 2, 3, 4, 5, 6.

SF= 256, 128, 64, 32, 16, 8, 4.

Control part carries Layer 1 control information with SF = 256. Slot format is the same as CPCH PC-P part.

150

PCPCH Message Part Spreading

jβccc

cd βd

Sc-msg,n

I+jQ

PCPCH messagecontrol part

PCPCH messagedata part

Q

I

151

Control part is always spread by cc = Cch,256,0

Data part is spread by cd = Cch,SF,k with SF = 4 to 256 and k = SF/4.A UE is allowed to increase SF during the message transmission on a frame by frame basis.

PCPCH Message Part OVSF Code Allocation

152

The set of scrambling codes are10 ms long

Cell-specific

one-to-one correspondence to the signature sequences and the access sub-channel used by the access preamble part.

Both long or short scrambling codes can be used.

There are 64 uplink scrambling codes defined per cell and 32768 different PCPCH scrambling codes defined in the system.

PCPCH Message Part Scrambling Code Allocation

153

The n:th PCPCH message part scrambling code, denoted Sc-msg,n, where n =8192,8193, …,40959 is based on the scrambling sequence and is defined as:

Long scrambling codes : Sr-msg,n(i) = Clong,n(i ), i = 0, 1, …, 38399

Short scrambling codes : Sr-msg,n(i) = Cshort,n(i), i = 0, 1, …, 38399

The 32768 PCPCH scrambling codes are divided into 512 groups with 64 codes in each group.

There is a one-to-one correspondence between the group of PCPCH preamble scrambling codes in a cell and the primary scrambling code used in the downlink of the cell.

PCPCH Message Part Scrambling Code Allocation

154

Uplink Modulation

The modulation chip rate is 3.84 Mcps.The complex-valued chip sequence generated by the spreading process is QPSK modulated.

S

Im{S}

Re{S}

cos(ωt)

Complex-valuedchip sequencefrom spreadingoperations

-sin(ωt)

Splitreal &imag.parts

Pulse-shaping

Pulse-shaping

155

Uplink Modulation

The uplink modulation should be designed:The audible interference from the terminal transmission is minimized.The terminal amplifier efficiency is maximized.

Audible interference:Discontinuous uplink transmission can cause audible interference to audio equipment that is very close to the terminal.Solution: WCDMA uplink doesn’t adopt time multiplexing.

Physical Layer Control Information (DPDCH)

User Data (DPDCH) User Data (DPDCH)DTX Period



WCDMA Downlink Physical Layer

157

Table of ContentsIntroductionDownlink Transmit Diversity

Open loop transmit diversitySpace Time Block Coding Based Transmit Antenna Diversity (STTD)Time Switched Transmit Diversity for Synchronization Channel (TSTD)

Closed loop transmit diversityDedicated Downlink Physical Channels

Downlink Dedicated Physical Channel (DL DPCH)Common Downlink Physical Channels1. Common Pilot Channel (CPICH)2. Primary Common Control Physical Channel (P-CCPCH)3. Secondary Common Control Physical Channel (S-CCPCH)

158

Table of Contents

Common Downlink Physical Channels (continue)4. Synchronization Channel (SCH)5. Physical Downlink Shared Channel (PDSCH)6. Acquisition Indicator Channel (AICH)7. CPCH Access Preamble Acquisition Indicator Channel (AP-AICH)8. CPCH Collision Detection/Channel Assignment Indicator Channel

(CD/CA-ICH)9. Page indicator channel (PICH)10. CPCH Status Indicator Channel (CSICH)

SpreadingModulationTiming Relationship

159

Introduction

Downlink DPCHAICH, CPICHCCPCH, PICH

IdleMS

On-lineMS

Power-onMS

SCH

160

Downlink Transmit Diversity

Open loop transmit diversity: STTD and TSTDClosed loop transmit diversity BS

ˇˇ-DL-DPCCH for CPCH

-ˇ-CD/CA-ICH

-ˇ-AP-AICH

–ˇ–CSICH

–ˇ–AICH

ˇˇ–PDSCH

–ˇ–PICH

ˇˇ–DPCH

–ˇ–S-CCPCH

––ˇSCH

–ˇ–P-CCPCH

ModeSTTDTSTD

Closed loopOpen loop modePhysical channel type

161

The STTD encoding is optional in UTRAN. STTD support is mandatory at the UE.STTD encoding is applied on blocks of 4 consecutive channel bits.

b 0 b 1 b 2 b 3

b 0 b 1 b 2 b 3

-b 2 b 3 b 0 -b 1

A ntenna 1

A ntenna 2C hanne l b its

S T T D enco d ed channe l b itsfo r an tenna 1 and an tenna 2 .

Space Time Block Coding Based Transmit Antenna Diversity (STTD)

162

Prim arySCH

SecondarySCH

256 ch ips

2560 chips

O ne 10 m s SCH radio fram e

acsi,0

acp

acsi,1

acp

acsi,14

acp

S lot #0 Slo t #1 Slot #14

TSTD can be applied to TSTD.TSTD for the SCH is optional in UTRAN, while TSTD support is mandatory in the UE.

Antenna 1

Antenna 2

acsi,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)

Time Switched Transmit Diversity for SCH (TSTD)

163

Spread/scramblew1

w2

DPCHDPCCH

DPDCH

∑

CPICH1

∑

CPICH2

Ant1

Ant2

Weight Generation

w1 w2

Determine FBI messagefrom Uplink DPCCH

Closed Loop Mode Transmit Diversity

164

The spread complex valued signal is fed to both TX antenna branches, and weighted with antenna specific weight factors w1 and w2 , where wi = ai + jbi .The weight factors (phase adjustments in closed loop mode 1 and phase/amplitude adjustments in closed loop mode 2) are determined by the UE, and signalled to the UTRAN access point (=cell transceiver) using the D sub-field of the FBI field of uplink DPCCH.For the closed loop mode 1 different (orthogonal) dedicated pilot symbols in the DPCCH are sent on the 2 different antennas. For closed loop mode 2 the same dedicated pilot symbols in the DPCCH are sent on both antennas.

Closed Loop Mode Transmit Diversity

165

Summary of number of feedback information bits per slot, NFBD, feedback command length in slots, NW, feedback command rate, feedback bit rate, number of phase bits, Nph, per signalling word, number of amplitude bits, Npo, per signalling word and amount of constellation rotation at UE for the two closed loop modes.

N/A311500 bps1500 Hz412

π/2101500 bps1500 Hz111

Constellation rotation

NphNpoFeedback bit rate

Update rate

NWNFBDClosed loop mode

Number of Feedback Information in Closed Loop Transmit Diversity

166

The UE uses the CPICH to separately estimate the channels seen from each antenna.Once every slot, the UE computes the phase adjustment, φ, and for mode 2 the amplitude adjustment that should be applied at the UTRAN access point to maximise the UE received power.The UE feeds back to the UTRAN access point the information on which phase/power settings to use.Feedback Signalling Message (FSM) bits are transmitted in the portion of FBI field of uplink DPCCH slot(s) assigned to closed loop mode transmit diversity, the FBI D field. Each message is of length NW = Npo+Nph bits.

Determination of Feedback Information in Closed Loop Mode Transmit Diversity

167

Closed Loop Mode 1The UE uses the CPICH transmitted both from antenna 1 and antenna 2 to calculate the phase adjustment to be applied at UTRAN access point to maximise the UE received power.In each slot, UE calculates the optimum phase adjustment, φ, for antenna 2, which is then quantized into having two possible values as follows:

where

If = 0, a command '0' is sent to UTRAN using the FSMphfield. If = π, command '1' is sent to UTRAN using the FSMphfield.

⎩⎨⎧ ≤−<

=otherwise,0

2/3)(2/ if, πφφππφ

irQ

⎩⎨⎧

==

=13,11,9,7,5,3,1,2/

14,12,10,8,6,4,2,0,0)(

ii

ir πφ

QφQφ

168

Closed Loop Mode 2In closed loop mode 2 there are 16 possible combinations of phase and power adjustment.

0.20.81

0.80.20

Power_ant2Power_ant1FSMpo

3π/4100π/2101π/41110110

-π/4010-π/2011-3π/4001

π000Phase difference between antennas (radians)FSMph

FSMpo subfield ofsignalling message

FSMph subfield ofsignalling message

169

There is only one type of downlink dedicated physical channel, the Downlink Dedicated Physical Channel (DL DPCH). Within one downlink DPCH, dedicated data generated at Layer 2 and above, i.e. the dedicated transport channel (DCH), is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits, TPC commands, and an optional TFCI).

Downlink Dedicated Physical Channels(DPCH)

170

Frame Structure of DL DPCH

One radio frame, Tf = 10 ms

TPC NTPC bits



Data2Ndata2 bits

DPDCHTFCI

NTFCI bitsPilot

Npilot bitsData1

Ndata1 bits

DPDCH DPCCH DPCCH

171

DL DPCHParameters

Each frame= 15 slots = 10 msEach slot= 2560 chips

Each slot= one power-control period.

SF = 512/2k (e.g., SF=512, 256, ...,4)Two basic types

With TFCI (for several simultaneous services)Without TFCI (fixed-rate services)

It is the UTRAN that determines if a TFCI should be transmitted and it is mandatory for all UEs to support the use of TFCI in the downlink.

172

DL DPCH Compressed Mode

In compressed frames, a different slot format is used compared to normal mode.There are two possible compressed slot formats that are labelled A and B.

Slot format B shall be used in frames compressed by spreading factor reduction.Slot format A shall be used in frames compressed by puncturing or higher layer scheduling.

Reference: 3GPP TS 25-212 V3.8.0 4.4 Compressed Mode

173

DL DPCH Fields (table is not completed)

8-14442822025615305A

154221022025615305

8-148042444012830604B

8-144021222025615304A

154021222025615304

8-144442444012830603B

8-142421022025615303A

152221222025615303

8-144042844012830602B

8-142021422025615302A

152021422025615302

8-14844402025615301B

1542220105127.5151

8-14804802025615300B

8-1440240105127.5150A

1540240105127.5150

NPilotNTFCINTPCNData2NData1

Transmittedslots per

radio frame NTr

DPCCHBits/Slot

DPDCHBits/Slot

Bits /Slot

SFChannelSymbol

Rate (ksps)

ChanneBit Rate(kbps)

SlotFormat #i

174

DL DPCH Pilot Bit Patterns

100000101101110011111010010001

111111111111111111111111111111

111110011101101000001100010010

111111111111111111111111111111

101001000110000010110111001111

111111111111111111111111111111

110001001011111001110110100000

111111111111111111111111111111

101001000110000010110111001111

111111111111111111111111111111

110001001011111001110110100000

111111111111111111111111111111

110001001011111001110110100000

111111111111111111111111111111

110001001011111001110110100000

Slot #01234567891011121314

765432103210100Symbol#

Npilot = 16(*3)

Npilot = 8(*2)

Npilot = 4(*1)

Npilot=2

175

DL DPCH TPC & TFCI

TPC

TFCITFCI value in each radio frame corresponds to a certain combination of bit rates of the DCHscurrently in use.

10

1111111100000000

11110000

1100

NTPC = 8NTPC = 4NTPC = 2

Transmitter Power Control Command

TPC Bit Pattern

176

DL DPCH Multi-Code Transmission

TransmissionPower Physical Channel 1

TransmissionPower Physical Channel 2

TransmissionPower Physical Channel L

DPDCH

One Slot (2560 chips)

TFCI PilotTPC

• •

•

DPDCH Condition:

Total bit rate to be transmitted exceeds the maximum bit rate

Layer 1 control information is transmitted only on the first DL DPCH.

Multicodetransmission is mapped onto several parallel downlink DPCHs using the same spreading factor.

177

Common Pilot Channel (CPICH)Frame Structure:

Pre-defined symbol sequence


Tslot = 2560 chips , 20 bits = 10 symbols


178

Common Pilot Channel

The CPICH is a fixed rate (30 kbps, SF=256) downlink physical channel that carries a pre-defined bit/symbol sequence.In case transmit diversity (open or closed loop) is used on any downlink channel in the cell, the CPICH shall be transmitted from both antennas using the same channelization and scrambling code.There are two types of Common pilot channels:

The Primary CPICH.The Secondary CPICH.

179

Transmit Diversity of CPICH

Modulation pattern for Common Pilot Channel (with A = 1+j)

slot #1

Frame#i+1Frame#i

slot #14

A A A A A A A A A A A A A A A A A A A A A A A A

-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenna 2

Antenna 1

slot #0

Frame Boundary

In case of no transmit diversity, thesymbol sequence of Antenna 1 is used.

180

The Primary CPICHThe Primary Common Pilot Channel (P-CPICH) has the following characteristics:

The same channelization code is always used for the P-CPICH;The P-CPICH is scrambled by the primary scrambling code;There is one and only one P-CPICH per cell;The P-CPICH is broadcast over the entire cell.

The Primary CPICH is a phase reference for the following downlink channels: SCH, Primary CCPCH, AICH, PICH AP-AICH, CD/CA-ICH, CSICH, DL-DPCCH for CPCH and the S-CCPCH.By default, the Primary CPICH is also a phase reference for downlink DPCH and any associated PDSCH.The Primary CPICH is always a phase reference for a downlink physical channel using closed loop TX diversity.

181

A Secondary Common Pilot Channel (S-CPICH) has the following characteristics:

An arbitrary channelization code of SF=256 is used for the S-CPICH;A S-CPICH is scrambled by either the primary or a secondary scrambling code;There may be zero, one, or several S-CPICHs per cell;A S-CPICH may be transmitted over the entire cell or only over a part of the cell;

A Secondary CPICH may be a phase reference for a downlink DPCH.The Secondary CPICH can be a phase reference for a downlink physical channel using open loop TX diversity, instead of the Primary CPICH being a phase reference.

Secondary Common Pilot Channel(S-CPICH)

182

Downlink Phase Reference

––ˇDL-DPCCH for CPCH

––ˇCSICH

––ˇAICH

ˇˇˇPDSCH*

––ˇPICH

ˇˇˇDPCH

––ˇS-CCPCH

––ˇSCH

––ˇP-CCPCH

Dedicated PilotSecondary-CPICHPrimary-CPICHPhysical Channel Type

Note *: the same phase reference as with the associated DPCH shall be used.

183

Fixed rate: 30 kbps, SF=256.Used to carry the BCH transport channel.No TPC commands, no TFCI and no pilot bits.Frame structure:

Data Ndata1=18 bits


Tslot = 2560 chips , 20 bits


(Tx OFF)

256 chips

Primary Common Control Physical Channel (P-CCPCH)

184

S-CCPCH is used to carry the FACH and PCH. Two types of S-CCPCHs: those that include TFCI and those that do not include TFCI.It is the UTRAN that determines if a TFCI should be transmitted, hence making it mandatory for all UEs to support the use of TFCI.



Pilot Npilot bits

Data Ndata1 bits


TFCI NTFCI bits

Secondary Common Control Physical Channel (S-CCPCH)

185

Secondary CCPCH Fields

816125612801920049601920 17

80127212801920049601920 16

8166166409600848096015

806326409600848096014

816296320480016240480 13

80312320480016240480 12

88144160240032120240 11

80152160240032120240 10

88648012006460120 9

80728012006460120 8

2830406001283060 7

2038406001283060 6

0832406001283060 5

0040406001283060 4

2810203002561530 3

2018203002561530 2

0812203002561530 1

0020203002561530 0

NTFCINpilotNdata1Bits/ Slot

Bits/ Frame

SFChannel SymbolRate (ksps)


Slot Format #i

186

S-CCPCH Pilot Symbol Patterns

100000101101110011111010010001

111111111111111111111111111111

111110011101101000001100010010

111111111111111111111111111111

101001000110000010110111001111

111111111111111111111111111111

110001001011111001110110100000

111111111111111111111111111111

101001000110000010110111001111

111111111111111111111111111111

110001001011111001110110100000

111111111111111111111111111111

Slot #01234567891011121314

765432103210Symbol #

Npilot = 16Npilot = 8

187

Characteristics of S-CCPCHThe FACH and PCH can be mapped to the same or to separate Secondary CCPCHs.If FACH and PCH are mapped to the same S-CCPCH, they can be mapped to the same frame.The main difference between a CCPCH and a downlink dedicated physical channel is that a CCPCH is not inner-loop power controlled.The main difference between the P-CCPCH and S-CCPCH is that the transport channel mapped to the P-CCPCH can only have a fixed predefined transport format combination, while the S-CCPCH support multiple transport format combinations using TFCI.

188

Synchronization Channel (SCH)The SCH is a downlink signal used for cell search.The SCH consists of: the Primary and Secondary SCH.The 10 ms radio frames of the Primary and Secondary SCH are divided into 15 slots, each of length 2560 chips.

PrimarySCH

SecondarySCH

256 chips

2560 chips

One 10 ms SCH radio frame

acsi,0

acp

acsi,1

acp

acsi,14

acp

Slot #0 Slot #1 Slot #14

189

Synchronization Channel (SCH)

The Primary SCH consists of a modulated code of length 256 chips, the Primary Synchronisation Code (PSC), transmitted once every slot.The PSC is the same for every cell in the system.The primary and secondary synchronization codes are modulated by the symbol a, which indicates the presence/ absence of STTD encoding on the P-CCPCH:

a = -1P-CCPCH not STTD encodeda = +1P-CCPCH STTD encoded

190

Synchronization Channel (SCH)

The Secondary SCH consists of repeatedly transmitting a length 15 sequence of modulated codes of length 256 chips, the Secondary Synchronisation Codes (SSC), transmitted in parallel with the Primary SCH.The SSC is denoted cs

i,k, where i = 0, 1, …, 63 is the number of the scrambling code group, and k = 0, 1, …, 14 is the slot number.Each SSC is chosen from a set of 16 different codes of length 256.This sequence on the Secondary SCH indicates which of the code groups the cell's downlink scrambling code belongs to.

191

The PDSCH is used to carry the Downlink Shared Channel (DSCH).A PDSCH corresponds to a channelisation code below or at a PDSCH root channelisation code.A PDSCH is allocated on a radio frame basis to a UE.Within one radio frame, UTRAN may allocate different PDSCHs under the same PDSCH root channelisation code to different UEs based on code multiplexing.Within the same radio frame, multiple parallel PDSCHs, with the same spreading factor, may be allocated to a single UE.All the PDSCHs are operated with radio frame synchronisation.

Physical Downlink Shared Channel (PDSCH)

192

PDSCHs allocated to the same UE on different radio frames may have different spreading factors.Frame structure of PDSCH:



Data Ndata1 bits



193

For each radio frame, each PDSCH is associated with one downlink DPCH. The PDSCH and associated DPCH do not necessarily have the same spreading factors and are not necessarily frame aligned.All relevant Layer 1 control information is transmitted on the DPCCH part of the associated DPCH, i.e. the PDSCH does not carry Layer 1 information. To indicate for UE that there is data to decode on the DSCH, the TFCI field of the associated DPCH shall be used.The TFCI informs the UE of the instantaneous transport format parameters related to the PDSCH as well as the channelisation code of the PDSCH.


194

The Acquisition Indicator channel (AICH) is a fixed rate (SF=256) physical channel used to carry Acquisition Indicators (AI).Acquisition Indicator AIs corresponds to signature s on the PRACH.Frame structure:

1024 chips

Transmission Off

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

a1 a2a0 a31a30

AI part = 4096 chips, 32 real-valued symbols

20 ms


195

The AICH consists of a repeated sequence of 15 consecutive access slots (AS), each of length 5120 chips. Each access slot consists of two parts, an Acquisition-Indicator (AI) part consisting of 32 real-valued symbols a0, …, a31 and a part of duration 1024 chips with no transmission that is not formally part of the AICH.The part of the slot with no transmission is reserved for possible use by CSICH or possible future use by other physical channels.


196

The spreading factor (SF) used for channelisation of the AICH is 256.The phase reference for the AICH is the Primary CPICH.The real-valued symbols a0, a1, …, a31 are given by

AIs (1, 0, -1) ~( ACK, No ACK, NACK)Each slot can ack 16 signatures.

∑=

=15

0js,sj bAIa

s


197

AICH signature patterns bs,0, …, bs,31:


198

The AP-AICH is a fixed rate (SF=256) physical channel used to carry AP acquisition indicators (API) of CPCH.AP acquisition indicator APIs corresponds to AP signature s transmitted by UE.Frame structure:

1024 chips

Transmission Off

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

a1 a2a0 a31a30

API part = 4096 chips, 32 real-valued symbols

20 ms

CPCH Access Preamble Acquisition Indicator Channel (AP-AICH)

199

AP-AICH and AICH may use the same or different channelisation codes. The phase reference for the AP-AICH is the Primary CPICH.The AP-AICH has a part of duration 4096 chips where the AP acquisition indicator (API) is transmitted, followed by a part of duration 1024chips with no transmission that is not formally part of the AP-AICH.The spreading factor (SF) used for channelisation of the AP-AICH is 256.APIs (1, 0, -1) ~( ACK, No ACK, NACK)

CPCH Access Preamble Acquisition Indicator Channel (AP-AICH)

200

The CD/CA-ICH is a fixed rate (SF=256) physical channel used to carry CD Indicator (CDI) only if the CA is not active, or CD Indicator/CA Indicator (CDI/CAI) at the same time if the CA is active.CD/CA-ICH frame structure:

1024 chips

Transmission Off

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

a1 a2a0 a31a30

CDI/CAI part = 4096 chips, 32 real-valued symbols

20 ms

CPCH Collision Detection/Channel Assignment Indicator Channel (CD/CA-ICH)

201

CD/CA-ICH and AP-AICH may use the same or different channelisation codes.The CD/CA-ICH has a part of duration of 4096chips where the CDI/CAI is transmitted, followed by a part of duration 1024chips with no transmission that is not formally part of the CD/CA-ICH.The spreading factor (SF) used for channelisation of the CD/CA-ICH is 256.

CPCH Collision Detection/Channel Assignment Indicator Channel (CD/CA-ICH)

202

Paging Indicator Channel (PICH)The PCH is to provide terminals with efficient sleep mode operation.For detection of the PICH, the terminal needs to obtain the phase reference from the CPICH, and as with the AICH, the PICH needs to be heard by all terminals in the cell and thus needs to be sent at high power level without power control.The PICH is a fixed rate (SF=256) physical channel used to carry the paging indicators.The PICH is always associated with an S-CCPCH to which a PCH transport channel is mapped.

203


One PICH radio frame of length 10 ms consists of 300 bits (b0, b1, …, b299).288 bits (b0, b1, …, b287) are used to carry paging indicators.The remaining 12 bits are not formally part of the PICH and shall not be transmitted.The part of the frame with no transmission is reserved for possible future use.

b1b0

288 bits for paging indication12 bits (transmission

off)

One radio frame (10 ms)

b287 b288 b299

204


In each PICH frame, Np paging indicators {P0, …, PNp-1} are transmitted, where Np=18, 36, 72, or 144.The PI calculated by higher layers for use for a certain UE, is associated to the paging indicator Pq, where q is computed as a function of:

The PI computed by higher layers;The SFN of the P-CCPCH radio frame during which the start of the PICH radio frame occurs;The number of paging indicators per frame (Np).

⎣ ⎦ ⎣ ⎦ ⎣ ⎦( )( )( ) NpNpSFNSFNSFNSFNPIq mod144

144mod512/64/8/18 ⎟⎟⎠

⎞⎜⎜⎝

⎛⎥⎦⎥

⎢⎣⎢ ×+++×+=

205

Paging Indicator Channel (PICH)The PI calculated by higher layers is associated with the value of the paging indicator Pq.If a paging indicator in a certain frame is set to "1“, it is an indication that UEs associated with this paging indicator and PI should read the corresponding frame of the associated S-CCPCH.The PI bitmap in the PCH data frames over Iub contains indication values for all higher layer PI values possible. Each bit in the bitmap indicates if the paging indicator associated with that particular PI shall be set to 0 or 1. Hence, the calculation in the formula above is to be performed in Node B to make the association between PI and Pq.

206

Paging Indicator Channel (PICH)Mapping of paging indicators Pq to PICH bits

{b2q, b2q+1} = {+1,+1}

{b2q, b2q+1} ={-1,-1}

Np=144

{b4q, …, b4q+3} ={+1, +1,…,+1}

{b4q, …, b4q+3} = {-1, -1,…,-1}

Np=72

{b8q, …, b8q+7} = {+1,+1,…,+1}

{b8q, …, b8q+7} = {-1,-1,…,-1}

Np=36

{b16q, …, b16q+15} = {+1,+1,…,+1}

{b16q, …, b16q+15} = {-1,-1,…,-1}

Np=18

Pq = 0Pq = 1Number of paging indicators per frame

(Np)

207


The CSICH is a fixed rate (SF=256) physical channel used to carry CPCH status information.The CSICH bits indicate the availability of each physical CPCH channel and are used to tell the terminal to initiate access only on a free channel but, on the other hand, to accept a channel assignment command to an unused channel.A CSICH is always associated with a physical channel used for transmission of CPCH AP-AICH and uses the same channelization and scrambling codes.

208


The CSICH frame consists of 15 consecutive access slots (AS) each of length 40 bits.Each access slot consists of two parts, a part of duration 4096 chips with no transmission, and a Status Indicator (SI) part consisting of 8 bits b8i,….b8i+7, where i is the access slot number. The part of the slot with no transmission is reserved for use byAICH, AP-AICH or CD/CA-ICH.

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

b8i b8i+1

4096 chips

Transmission off

SI part

20 ms

b8i+7b8i+6

209


The modulation used by the CSICH is the same as for the PICH.The phase reference for the CSICH is the Primary CPICH.N Status Indicators {SI0, …, SIN-1} shall be transmitted in each CSICH frame.The Status Indicators shall be transmitted in all the access slots of the CSICH frame, even if some signatures and/or access slots are shared between CPCH and RACH.

210

CPCH Status Indicator Channel (CSICH)Mapping of Status Indicators (SI) to CSICH bits:

{b2n, b2n+1} = {+1,+1}{b2n, b2n+1} = {-1,-1}N=60

{b4n, …, b4n+3} ={+1, +1, +1, +1}

{b4n, …, b4n+3} ={-1, -1, -1, -1}

N=30

{b8n, …, b8n+7} ={+1,+1,…,+1}

{b8n, …, b8n+7} = {-1,-1,…,-1}

N=15

{b24n, …, b24n+23} ={+1,+1,…,+1}

{b24n, …, b24n+23} = {-1,-1,…,-1}

N=5

{b40n, …, b40n+39} ={+1,+1,…,+1}

{b40n, …, b40n+39} ={-1,-1,…,-1}

N=3

{b0, …, b119} ={+1,+1,…,+1}

{b0, …, b119} = {-1,-1,…,-1}

N=1

SIn = 0SIn = 1Number of SI per frame (N)

211

k:th S-CCPCH

AICH access slots

Secondary SCH

Primary SCH

τS-CCPCH,k

10 ms

τPICH

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

Radio frame with (SFN modulo 2) = 0 Radio frame with (SFN modulo 2) = 1

τDPCH,n

P-CCPCH

Any CPICH

PICH for k:th S-CCPCH

Any PDSCH

n:th DPCH

10 ms

Timing Relationship between Physical Channels

212

The P-CCPCH, on which the cell SFN is transmitted, is used as timing reference for all the physical channels, directly for downlink and indirectly for uplink.Transmission timing for uplink physical channels is given by the received timing of downlink physical channels.SCH (primary and secondary), CPICH (primary and secondary), P-CCPCH, and PDSCH have identical frame timings.


213

The S-CCPCH timing may be different for different S-CCPCHs, but the offset from the P-CCPCH frame timing is a multiple of 256 chips, i.e. τS-CCPCH,k = Tk × 256 chip, Tk ∈ {0, 1, …, 149}.The PICH timing is τPICH = 7680 chips prior to its corresponding S-CCPCH frame timing, i.e. the timing of the S-CCPCH carrying the PCH transport channel with the corresponding paging information.AICH access slots #0 starts the same time as P-CCPCH frames with (SFN modulo 2) = 0.The DPCH timing may be different for different DPCHs, but the offset from the P-CCPCH frame timing is a multiple of 256 chips, i.e. τDPCH,n = Tn × 256 chip, Tn ∈ {0, 1, …, 149}.


214

PICH/S-CCPCH Timing Relation

The S-CCPCH frame that carries the paging information is related to the paging indicators in the PICH frame.A paging indicator set in a PICH frame means that the paging message is transmitted on the PCH in the S-CCPCH frame starting τPICH chips after the transmitted PICH frame.

τPICH

Associated S-CCPCH frame

PICH frame containing paging indicator

215

PRACH/AICH Timing RelationThe downlink AICH is divided into downlink access slots, each access slot is of length 5120 chips.The uplink PRACH is divided into uplink access slots, each access slot is of length 5120 chips.Uplink access slot number n is transmitted from the UE τp-a chips prior to the reception of downlink access slot number n, n = 0, 1, …, 14.

One access slot

τp-a

τp-mτp-p

Pre-amble

Pre-amble Message part

Acq.Ind.AICH access

slots RX at UE

PRACH accessslots TX at UE

216

PRACH/AICH Timing Relation

Transmission of downlink acquisition indicators may only start at the beginning of a downlink access slot.Similarly, transmission of uplink RACH preambles and RACH message parts may only start at the beginning of an uplink access slot.The preamble-to-preamble distance τp-p shall be larger than or equal to the minimum preamble-to-preamble distanceτp-p,min, i.e. τp-p ≥ τp-p,min.

217

PRACH/AICH Timing RelationIn addition to τp-p,min, the preamble-to-AI distance τp-aand preamble-to-message distance τp-m are defined as follows:

When AICH_Transmission_Timing is set to 0, thenτp-p,min = 15360 chips (3 access slots)τp-a = 7680 chipsτp-m = 15360 chips (3 access slots)

When AICH_Transmission_Timing is set to 1, thenτp-p,min = 20480 chips (4 access slots)τp-a = 12800 chipsτp-m = 20480 chips (4 access slots)

The parameter AICH_Transmission_Timing is signalled by higher layers.

218

DPCH/PDSCH Timing RelationThe start of a DPCH frame is denoted TDPCH and the start of the associated PDSCH frame is denoted TPDSCH.Any DPCH frame is associated to one PDSCH frame through the relation 46080 chips ≤ TPDSCH - TDPCH < 84480 chips, i.e., the associated PDSCH frame starts between three slots after the end of the DPCH frame and 18 slots after the end of the DPCH frame.

TDPCH

Associated PDSCH frame

DPCH frame

TPDSCH

219

DPCCH/DPDCH Timing RelationsUplink

In uplink the DPCCH and all the DPDCHs transmitted from one UE have the same frame timing.

DownlinkIn downlink, the DPCCH and all the DPDCHs carrying CCTrCHs of dedicated type to one UE have the same frame timing.Note: support of multiple CCTrChs of dedicated type is not part of the current release.

Uplink/downlink timing at UEAt the UE, the uplink DPCCH/DPDCH frame transmission takes placeapproximately T0 chips after the reception of the first detected path (in time) of the corresponding downlink DPCCH/DPDCH frame.T0 is a constant defined to be 1024 chips.

220

Spreading without SCHThe non-spread physical channel consists of a sequence of real-valued symbols.For all channels except AICH, the symbols can take the three values +1, -1, and 0, where 0 indicates DTX.For AICH, the symbol values depend on the exact combination of acquisition indicators to be transmitted.

I

Any downlinkphysical channelexcept SCH

S→P

Cch,SF,m

j

Sdl,n

Q

I+jQ S

221

Spreading with SCH

Different downlinkPhysical channels

Σ

G1

G2

GP

GS

S-SCH

P-SCH Σ

222

Downlink Scrambling Codes

8192 codes are chosen from a total of 218-1 scrambling codes, numbered 0,…,262142

These chosen scrambling codes are divided into 512 sets, each set has

One primary scrambling codeCode number, n=16*i (i=0…511)

15 secondary scrambling codes Code number, n=16*i+k (k=1…15)

223

Downlink Scrambling Codes512 primary scrambling codes

Further divided into 64 scrambling code groups

Each group consisting of 8 primary scrambling codes

The j:th scrambling code group consists of primary scrambling codes 16*8*j+16*k (j=0..63 & k=0..7)

Each cell is allocated one and only one primary scrambling code.The primary CCPCH, primary CPICH, PICH, AICH, AP-AICH, CD/CA-ICH, CSICH and S-CCPCH carrying PCH are always transmitted using the primary scrambling code.The other downlink physical channels can be transmitted with either the primary scrambling code or a secondary scrambling code from the set associated with the primary scrambling code of the cell.

224

Configuration of Downlink Scrambling Code Generator

I

Q

1

1 0

02

2

3

3

4

4

5

5

6

6

7

7

8

8

9

9

17

17

16

16

15

15

14

14

13

13

12

12

11

11

10

10

225

Downlink Scrambling CodesConstructed by combining two real sequencesEach is constructed as the position wise modulo 2 sum of two binary m-sequences, x and y

Generator polynomials is of degree 18

38400 chip segments (10 ms radio frame)

Gold sequences

x sequence: generator polynomial 1+X7+X18

Initial: x (0)=1, x(1)= x(2)=...= x (16)= x (17)=0

x(i+18) =x(i+7) + x(i) modulo 2, i=0,…,218-20,

y sequence: generator polynomial 1+y 5+y 7+ y 10+y 18

Initial: y(0)=y(1)= … =y(16)= y(17)=1

y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2, i=0,…, 218-20

226

Downlink Scrambling Codes

The nth Gold code sequence zn iszn(i) = x((i+n) modulo (218 - 1)) + y(i) modulo 2, i=0,…, 218-2

Mapping

The n:th complex scrambling code sequence Sdl,n is defined as:

.22,,1,01)(10)(1

)( 18 −=⎩⎨⎧

=−=+

= …iforizifizif

iZn

nn

Sdl,n(i) = Zn(i) + j Zn((i+131072) modulo (218-1)), i=0,1,…,38399.

227

Downlink Modulation

In the downlink, the complex-valued chip sequence generated by the spreading process is QPSK modulated:

T

Im{T}

Re{T}

cos(ωt)

Complex-valuedchip sequencefrom summingoperations

-sin(ωt)

Splitreal &imag.parts

Pulse-shaping

Pulse-shaping



Compressed Mode

229

Compressed ModeOften referred to as the slotted mode.Inter-frequency handovers are needed for utilization of hierarchical cell structures and for handovers to 2nd generation systems.To complete inter-frequency handovers, measurements on other frequencies while still having the connection running on the current frequency are needed:

Dual Receiver;Compressed Mode;

Lowering the data rate from higher layers.Variable spreading factor.Code rate increase.Puncturing at the physical layer.Multi-code.Higher order modulation. 3GPP TS 25.212 V.3.8.0 4.4

230

Compressed Mode

The specified Transmission Gap Length (TGL) are 3, 4, 7, 10, and 14 slots.

One frame(10 ms) Transmission gap available for

inter-frequency measurements

231

Compressed ModeIn compressed frames, TGL slots from Nfirst to Nlastare not used for transmission of data.The instantaneous transmit power is increased in the compressed frame in order to keep the quality (BER, FER, etc.) unaffected by the reduced processing gain.The amount of power increase depends on the transmission time reduction method.What frames are compressed, are decided by the network.When in compressed mode, compressed frames can occur periodically, or requested on demand.

232

Slot # (Nlast + 1)

Data

Pilot TFCI FBI TPC

Slot # (Nfirst – 1)

Data

Pilot TFCI FBI TPC

transmission gap

Compressed Mode Frame Structure in the Uplink

233

There are two different types of DL frame structures:Type A maximizes the transmission gap length.Type B is optimized for power control.

Type A: the pilot field of the last slot in the transmission gap is transmitted.Type B: the TPC field of the first slot in the transmission gap and the pilot field of the last slot in the transmission gap is transmitted.

Slot # (Nfirst - 1)

TPC

Data1TFCI Data2 PL

Slot # (Nlast + 1)

PL Data1TPC

TFCI Data2 PL

transmission gap

Slot # (Nfirst - 1)

TPC

Data1TFCI Data2 PL

Slot # (Nlast + 1)

PL Data1TPC

TFCI Data2 PL

transmission gap

TPC

A:

B:

Compressed Mode Frame Structure Types in the Downlink

234

When in compressed mode, the information normally transmitted during a 10 ms frame is compressed in time.The mechanisms provided for achieving this are:

puncturing,reduction of the spreading factor by a factor of two,higher layer scheduling.

In the downlink, all methods are supported while compressed mode by puncturing is not used in the uplink. The maximum idle length is defined to be 7 slots per one 10 ms frame.

Compressed Mode Transmission Time Reduction Method

235

Transmission gaps can be placed at different positions for interfrequency power measurement, acquisition of control channel of other system/carrier, and handover operation.There are two methods:

Single frame methodDouble frame method

# 1 4# N firs t-1(1 ) S in g le - fra m e m e th o d

(2 ) D o u b le - fra m e m e th o d

F irs t ra d io fra m e S e c o n d ra d io fra m e

R a d io fra m eT ra n s m is s io n g a p

T ra n s m is s io n g a p

# 0

# 1 4

# N la s t+ 1

# N firs t-1 # N la s t+ 1# 0

Compressed Mode Transmission Gap Position

236

Compressed Mode TGL

R a d io f r a m e

F ir s t r a d io f r a m e S e c o n d r a d io f r a m eT r a n s m is s io n g a p

( 2 ) D o u b le - f r a m e m e t h o d

( 1 ) S in g le - f r a m e m e t h o d

::

::

R a d io f r a m e

T r a n s m is s io n g a p





TGL=3,4, and 7.

TGL=3,4,7,10,14.

When the transmission gap spans two consecutive radio frames, Nfirst andTGL must be chosen so that at least 8 slots in each radio frame are transmitted.

237

Idle Lengths for UL

(D) =(7,7)9.3314

(D)=(3,7), (4,6), (5,5), (6,4) or (7,3)

6.6710

(S)(D)=(1,6), (2,5), (3,4), (4,3),

(5,2) or (6,1)

4.677

(S)(D) = (1,4), (2,3), (3, 2) or

(4,1)

3.335

(S)(D) =(1,3), (2,2) or (3,1)

2.674

(S)(D) =(1,2) or (2,1)

Spreading factor division by 2 or

Higher layer scheduling

2.00256 – 43

Idle frameCombining

Transmission timeReduction method

Idle length [ms]

Spreading Factor

TGL

(S): Single-frame method. (D): Double-frame method.(x,y) indicates x: the number of idle slots in the first frame,

y: the number of idle slots in the second frame.

238

Idle Lengths for DL

8.93 – 9.19B

(D) =(7,7)9.07 – 9.33A14

6.27 – 6.53B

(D)=(3,7), (4,6), (5,5), (6,4) or (7,3)

6.40 – 6.66A10

4.27 – 4.53B

(S)(D)=(1,6), (2,5), (3,4), (4,3),

(5,2) or (6,1)

4.40 – 4.66A7

2.93 – 3.19B

(S)(D) = (1,4), (2,3), (3, 2) or

(4,1)

3.07 – 3.33A5

2.27 – 2.53B

(S)(D) =(1,3), (2,2) or (3,1)

2.40 – 2.66A4

1.60 – 1.86B

(S)(D) =(1,2) or (2,1)

Puncturing, Spreading factor division by 2 or


1.73 – 1.99512 – 4A3

Idle frameCombining

Transmission timeReduction method

Idle length [ms]

Spreading Factor

DL FrameType

TGL

239

Idle Lengths for Combined UL/DL

(D) =(7,7)8.80 – 9.0614

(D)=(3,7), (4,6), (5,5), (6,4) or (7,3)

6.13 – 6.3910

(S)(D)=(1,6), (2,5), (3,4),

(4,3), (5,2) or (6,1)

4.13 – 4.397

(S)(D) = (1,4), (2,3), (3, 2)

or (4,1)

2.80 – 3.065

(S)(D) =(1,3), (2,2) or (3,1)

2.13 – 2.394

(S)(D) =(1,2) or (2,1)

DL:Puncturing,

Spreading factor division by 2 or


UL:Spreading factor division by 2 or


1.47 – 1.73DL:512 – 4

UL:256 – 4

A or B3

Idle frameCombining

Transmission time

Reduction method

Idle length [ms]

Spreading Factor

DL FrameType

TGL



Site Selection Diversity Transmission

241

Site selection diversity transmit power control (SSDT) is a macro diversity method in soft handover mode.This method is optional in UTRAN.The UE selects one of the cells from its active set to be ｀primary＇, all other cells are ｀non primary＇.

The main objective is to transmit on the downlink from the primary cell, thus reducing the interference caused by multiple transmissions in a soft handover mode.A second objective is to achieve fast site selection without network intervention, thus maintaining the advantage of the soft handover.


242

In order to select a primary cell, each cell is assigned a temporary identification (ID) and UE periodically informs a primary cell ID to the connecting cells.The non-primary cells selected by UE switch off the transmission power.The primary cell ID is delivered by UE to the active cells via uplink FBI field.SSDT activation, SSDT termination and ID assignment are all carried out by higher layer signalling.


243

Definition of Temporary Cell IDEach cell is given a temporary ID during SSDT and the ID is utilised as site selection signal.The ID is given a binary bit sequence.There are three different lengths of coded ID available denoted as "long", "medium" and "short".The network decides which length of coded ID is used.The ID code(s) are transmitted aligned to the radio frame structure (i.e. ID codes shall be terminated within a frame).If FBI space for sending the last ID code within a frame cannot be obtained, the first bit(s) from that ID code are punctured.

244

Settings of ID codes for 1 bit FBI

10101(0)1101001110100101101001h11100(0)0111100011110000111100g01110(0)1011010101101001011010f00111(0)0001111000111100001111e10010(0)1100110110011001100110d11011(0)0110011011001100110011c01001(0)1010101101010101010101b00000(0)0000000000000000000000a

"short""medium""long"ID label

ID code

245

Settings of ID codes for 2 bit FBI

110001

(0)110(1)001

(0)1100110(1)0011001

h

110110

(0)110(0)110

(0)1100110(0)1100110

g

011100

(0)011(1)100

(0)0110011(1)1001100

f

011011

(0)011(0)011

(0)0110011(0)0110011

e

101010

(0)101(1)010

(0)1010101(1)0101010

d

101101

(0)101(0)101

(0)1010101(0)1010101

c

000111

(0)000(1)111

(0)0000000(1)1111111

b

000000

(0)000(0)000

(0)0000000(0)0000000

a"short""medium""long"ID label

ID code (Column and Row denote slot position and FBI-bit position.)

246

TPC Procedure in the UE

The UE shall generate TPC commands to control the network transmit power and send them in the TPC field of the uplink DPCCH based on the downlink signals from the primary cell only.The UE selects a primary cell periodically by measuring the RSCP (Received Signal Code Power) of P-CPICHs transmitted by the active cells.The cell with the highest P-CPICH RSCP is detected as a primary cell.

247

Period of Primary Cell Update

At the UE, the primary ID code to be sent to the cells is segmented into a number of portions.These portions are distributed in the uplink FBI S-field.The cell in SSDT collects the distributed portions of the primary ID code and then detects the transmitted ID.

5 updates per frame 3 updates per frame "short"4 updates per frame 2 updates per frame "medium"2 updates per frame 1 update per frame "long"

21code lengthThe number of FBI bits per slot assigned for SSDT

248

Downlink Receiver Architecture

RF

ADC

SRRC

Slot Sync.

Frame Sync./Code Group Identification

Scrambling Code Identification

Multi-path Searcher Rake Finger Management

Frame Boundary / Scrambling Code

ChannelEstimation

CodeTracking

De-Spreading

De-Scrambling MRC Channel

Decoding

Cell Search

Rake Receiver

249

Uplink Receiver Architecture

RF

ADC

SRRC

PRACH Preamble Detection

Multi-path Searcher Rake Finger Management

ChannelEstimation

CodeTracking

De-Spreading

De-Scrambling MRC Channel

Decoding

Rake ReceiverFrame Boundary

250

Uplink Transmitter Functional Block

DI

DQ

Antipodal Conv.

“0”>+1, “1”>-1

Antipodal Conv.

“0”>+1, “1”>-1

∑

Pulse Shaping

Filter

Pulse Shaping

Filter

∑

Root Nyquist,r=0.22

Root Nyquist,r=0.22

Channel Model

TS′TS+

+

+

+

IC

IC

QC

Gain Controlch1C

256,1C

DPDCH

DPCCH

tAcos cω

tAsin cω

-Complex Gaussian

-MultipathRayleigh

-UMTS Channel

∑

+

−

251

Downlink Transmitter Functional Block

DI

DQ

jAntipodal Conv.

“0”>+1, “1”>-1 ∑

Pulse Shaping

Filter

Pulse Shaping

Filter

∑

Root Nyquist,r=0.22

Root Nyquist,r=0.22

Channel Model

-Complex Gaussian

-MultipathRayleigh

-UMTS Channel

TS′TS+

+

+

+

Other User Signals

IC

IC

QC

ch1C

ch1C

DPDCH1/DPCCH

Antipodal Conv.

“0”>+1, “1”>-1

Gain Control

∑+

−

Introductions to WCDMA FDD Mode Physical Layer

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Transcript of Introductions to WCDMA FDD Mode Physical Layer