WCDMA FDD Mode Physical Layer -...
Transcript of WCDMA FDD Mode Physical Layer -...
WCDMA FDD Mode Physical Layer
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Table of ContentsPhysical Layer General Description
WCDMA Uplink Physical Layer
WCDMA Downlink Physical Layer
Multiplexing and Channel Coding (MCC)
Reference: Textbook Chapter 6 and 3GPP TS 25.201,25.211, 25.212, 25.213, 25.214, and 25.215.
WCDMA Physical Layer General Description (3G TS 25.201)
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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
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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
3GPP RAN Specifications
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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
3GPP RAN Specifications
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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
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General Protocol ArchitectureThe 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.
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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 Layer
5. 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.
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Multiple Access
UTRA 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.
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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 Channel
Broadcast Channel (BCH) -- mandatoryBCH 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 ChannelPaging Channel (PCH) -- mandatory
PCH 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.
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Common Transport Channel
Random Access Channel (RACH) -- mandatoryRACH 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 Channel
Forward Access Channel (FACH) -- mandatoryFACH 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 Transport ChannelCommon Packet Channel (CPCH) -- optional
CPCH 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.
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Common Transport ChannelDownlink Shared Channel (DSCH) -- optional
DSCH 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.
Fixed codes per cell.
Fixed codes per cell.
According to maximum bit
rate.
CodeUsage
Uplink, only in TDD.
DownlinkUplinkUplinkDownlinkBothUplink/Downlink
USCHDSCHCPCHRACHFACHDCH
Shared ChannelsCommon ChannelDedicatedChannel
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Mapping of Transport Channels onto Physical Channels
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
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Interface Between Higher Layers and the Physical Layer
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
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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.
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Transport Format Combination Indicator (TFCI)
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.
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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
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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
WCDMA Uplink Physical Layer
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Table of ContentsOverview
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
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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
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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
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Uplink Physical ChannelsDedicated 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)
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Dedicated Uplink Physical ChannelsUL 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.
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Frame Structure for UL DPDCH/DPCCH
PilotNpilot bits
TPCNTPC bits
DataNdata bits
Tslot = 2560 chips, 10 bits
1 radio frame: Tf = 10 ms = 38400 chips
DPDCH
DPCCHFBI
NFBI bitsTFCI
NTFCI bits
Tslot = 2560 chips,
Slot #0 Slot #1 Slot #i Slot #14
Ndata= 10*2k bits (k=0,1,…,6)
One Power Control Period
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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
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UL DPCCH - Layer 1 Control InformationThe 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)
Channel Bit Rate (kbps)
Slot Format #i
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UL DPCCH - Layer 1 Control InformationPilot 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) –optional
TFCI informs the receiver about the instantaneous transport format combination of the transport channels.
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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).
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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
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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
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TFCI Bits
There 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.
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TPC Bit Patterns
10
1100
10
NTPC = 2NTPC = 1
Transmitter power control
command
TPC Bit Pattern
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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
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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.
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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.
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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
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OVSF Code Allocation for UL DPCHDPCCH 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}
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Scrambling Codes of UL DPCH
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
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Physical Random Access Channel (PRACH)
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.
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PRACH Access Slot Numbers and Their Spacing
#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
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Structure of the Random-Access Transmission
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.
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RACH Preamble Code Construction
Each 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
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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;
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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.
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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
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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
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Structure of the Random-Access Message Part Radio Frame
PilotNpilotbits
DataNdatabits
Slot #0 Slot #1 Slot #i Slot #14
Tslot = 2560 chips, 10*2k bits (k=0,1,2,3.)
Message part radio frame TRACH = 10 ms
Data
Control TFCINTFCIbits
Tslot = 2560 chips, 10 bits
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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.
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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
Channel BitRate (kbps)
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
WITS Lab, NSYSU.63
PRACH Message Part Pilot Bit Pattern
001010000111011
111111111111111
110001001101011
111111111111111
101001101110000
111111111111111
100011110101100
111111111111111
Slot #01234567891011121314
76543210Bit #
Npilot = 8
WITS Lab, NSYSU.64
Spreading of PRACH Message PartMessage part OVSF Code Allocation
Given 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
jβccc
cd βd
Sr-msg,n
I+jQ
PRACH messagecontrol part
PRACH messagedata part
Q
I
WITS Lab, NSYSU.65
PRACH Message Part Scrambling Code
The 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.
WITS Lab, NSYSU.66
Physical Common Packet Channel (PCPCH)
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.
WITS Lab, NSYSU.67
Structure of the CPCH Access Transmission
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
WITS Lab, NSYSU.68
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
WITS Lab, NSYSU.69
PCPCH Access Preamble Scrambling Code
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.
WITS Lab, NSYSU.70
CPCH Collision Detection (CD) Preamble Part
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
WITS Lab, NSYSU.71
PCPCH CD Preamble Scrambling Code
There 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.
WITS Lab, NSYSU.72
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.
12251015025615151
02261015025615150
NFBINTFCINTPCNpilotBits /Slot
Bits /Slot
SFChannelSymbol Rate
(ksps)
Channel BitRate (kbps)
SlotFormat #i
WITS Lab, NSYSU.73
Frame Structure for PCPCH
PilotNpilot bits
TPCNTPC bits
DataNdata bits
Tslot = 2560 chips, 10 bits
1 radio frame: Tf = 10 ms = 38400 chips
Data
ControlFBI
NFBI bitsTFCI
NTFCI bits
Tslot = 2560 chips,
Slot #0 Slot #1 Slot #i Slot #14
Ndata= 10*2k bits (k=0,1,…,6)
WITS Lab, NSYSU.74
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.
WITS Lab, NSYSU.75
PCPCH Message Part Spreading
jβccc
cd βd
Sc-msg,n
I+jQ
PCPCH messagecontrol part
PCPCH messagedata part
Q
I
WITS Lab, NSYSU.76
PCPCH Message Part OVSF Code Allocation
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.
WITS Lab, NSYSU.77
PCPCH Message Part Scrambling Code Allocation
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.
WITS Lab, NSYSU.78
PCPCH Message Part Scrambling Code Allocation
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.
WITS Lab, NSYSU.79
Uplink ModulationThe 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
WITS Lab, NSYSU.80
Uplink ModulationThe 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
WITS Lab, NSYSU.82
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)
WITS Lab, NSYSU.83
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
WITS Lab, NSYSU.84
Introduction
Downlink DPCHAICH, CPICHCCPCH, PICH
IdleMS
On-lineMS
Power-onMS
SCH
WITS Lab, NSYSU.85
Downlink Transmit DiversityOpen 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
WITS Lab, NSYSU.86
Space Time Block Coding Based Transmit Antenna Diversity (STTD)
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 hannel b its
ST T D encoded channel b itsfo r antenna 1 and antenna 2 .
WITS Lab, NSYSU.87
Time Switched Transmit Diversity for SCH (TSTD)
TSTD can be applied to TSTD.TSTD for the SCH is optional in UTRAN, while TSTD support is mandatory in the UE.Prim arySCH
SecondarySCH
256 chips
2560 chips
One 10 m s SCH radio fram e
acsi,0
acp
acsi,1
acp
acsi,14
acp
Slot #0 Slot #1 Slot #14
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)
WITS Lab, NSYSU.88
Spread/scramblew1
w2
DPCHDPCCH
DPDCH
∑
CPICH1
∑
CPICH2
Ant1
Ant2
Weight Generation
w1 w2
Determine FBI messagefrom Uplink DPCCH
3GPP TS 25.214 V3.9.0 Sect. 7
Closed Loop Mode Transmit Diversity
WITS Lab, NSYSU.89
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
WITS Lab, NSYSU.90
Number of Feedback Information in Closed Loop Transmit Diversity
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
WITS Lab, NSYSU.91
Determination of Feedback Information in Closed Loop Mode Transmit Diversity
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.
WITS Lab, NSYSU.92
Closed Loop Mode 1
The 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 FSMph field.
⎩⎨⎧ ≤−<
=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
WITS Lab, NSYSU.93
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
WITS Lab, NSYSU.94
Downlink Dedicated Physical Channels (DPCH)
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).
WITS Lab, NSYSU.95
Frame Structure of DL DPCH
One radio frame, Tf = 10 ms
TPC NTPC bits
Slot #0 Slot #1 Slot #i Slot #14
Tslot = 2560 chips, 10*2k bits (k=0..7)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
WITS Lab, NSYSU.96
DL DPCH
ParametersEach frame= 15 slots = 10 ms
Each 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.
WITS Lab, NSYSU.97
DL DPCH Compressed ModeIn 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
WITS Lab, NSYSU.98
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
WITS Lab, NSYSU.99
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
WITS Lab, NSYSU.100
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
WITS Lab, NSYSU.101
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.
WITS Lab, NSYSU.102
Common Pilot Channel (CPICH)Frame Structure:
Pre-defined symbol sequence
Slot #0 Slot #1 Slot #i Slot #14
Tslot = 2560 chips , 20 bits = 10 symbols
1 radio frame: Tf = 10 ms
WITS Lab, NSYSU.103
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.
WITS Lab, NSYSU.104
Transmit Diversity of CPICHModulation 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.
WITS Lab, NSYSU.105
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.
WITS Lab, NSYSU.106
Secondary Common Pilot Channel(S-CPICH)
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.
WITS Lab, NSYSU.107
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.
WITS Lab, NSYSU.108
Primary Common Control Physical Channel (P-CCPCH)
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
Slot #0 Slot #1 Slot #i Slot #14
Tslot = 2560 chips , 20 bits
1 radio frame: Tf = 10 ms
(Tx OFF)
256 chips
WITS Lab, NSYSU.109
Secondary Common Control Physical Channel (S-CCPCH)
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.
Slot #0 Slot #1 Slot #i Slot #14
Tslot = 2560 chips, 20*2k bits (k=0..6)
Pilot Npilot bits
Data Ndata1 bits
1 radio frame: Tf = 10 ms
TFCI NTFCI bits
WITS Lab, NSYSU.110
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)
Channel Bit Rate (kbps)
Slot Format #i
WITS Lab, NSYSU.111
S-CCPCH Pilot Symbol Patterns
100000101101110011111010010001
111111111111111111111111111111
111110011101101000001100010010
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
101001000110000010110111001111
111111111111111111111111111111
110001001011111001110110100000
111111111111111111111111111111
Slot #01234567891011121314
765432103210Symbol #
Npilot = 16Npilot = 8
WITS Lab, NSYSU.112
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.
WITS Lab, NSYSU.113
Synchronisation 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
WITS Lab, NSYSU.114
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
WITS Lab, NSYSU.115
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.
WITS Lab, NSYSU.116
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)
WITS Lab, NSYSU.117
Physical Downlink Shared Channel (PDSCH)
PDSCHs allocated to the same UE on different radio frames may have different spreading factors.Frame structure of PDSCH:
Slot #0 Slot #1 Slot #i Slot #14
Tslot = 2560 chips, 20*2k bits (k=0..6)
Data Ndata1 bits
1 radio frame: Tf = 10 ms
WITS Lab, NSYSU.118
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.
Physical Downlink Shared Channel (PDSCH)
WITS Lab, NSYSU.119
Acquisition Indicator Channel (AICH)
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
WITS Lab, NSYSU.120
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.
Acquisition Indicator Channel (AICH)
WITS Lab, NSYSU.121
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
Acquisition Indicator Channel (AICH)
WITS Lab, NSYSU.122
AICH signature patterns bs,0, …, bs,31:
Acquisition Indicator Channel (AICH)
WITS Lab, NSYSU.123
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)
WITS Lab, NSYSU.124
CPCH Access Preamble Acquisition Indicator Channel (AP-AICH)
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)
WITS Lab, NSYSU.125
CPCH Collision Detection/Channel Assignment Indicator Channel (CD/CA-ICH)
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
WITS Lab, NSYSU.126
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)
WITS Lab, NSYSU.127
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.
WITS Lab, NSYSU.128
Paging Indicator Channel (PICH)
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
WITS Lab, NSYSU.129
Paging Indicator Channel (PICH)
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 ⎟⎟⎠
⎞⎜⎜⎝
⎛⎥⎦⎥
⎢⎣⎢ ×+++×+=
WITS Lab, NSYSU.130
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.
WITS Lab, NSYSU.131
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)
WITS Lab, NSYSU.132
CPCH Status Indicator Channel (CSICH)
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.
WITS Lab, NSYSU.133
CPCH Status Indicator Channel (CSICH)
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
WITS Lab, NSYSU.134
CPCH Status Indicator Channel (CSICH)
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.
WITS Lab, NSYSU.135
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)
WITS Lab, NSYSU.136
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
WITS Lab, NSYSU.137
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.
Timing Relationship between Physical Channels
WITS Lab, NSYSU.138
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}.
Timing Relationship between Physical Channels
WITS Lab, NSYSU.139
PICH/S-CCPCH Timing RelationThe 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
WITS Lab, NSYSU.140
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
WITS Lab, NSYSU.141
PRACH/AICH Timing RelationTransmission 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.
WITS Lab, NSYSU.142
PRACH/AICH Timing Relation
In 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.
WITS Lab, NSYSU.143
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
WITS Lab, NSYSU.144
DPCCH/DPDCH Timing Relations
UplinkIn 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.
WITS Lab, NSYSU.145
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
WITS Lab, NSYSU.146
Spreading with SCH
Different downlinkPhysical channels
Σ
G1
G2
GP
GS
S-SCH
P-SCH Σ
WITS Lab, NSYSU.147
Downlink ModulationIn 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
Multiplexing and Channel Coding( 3G TS 25.212 )
WITS Lab, NSYSU.149
Table of ContentsOverview of MCCTransport channel related terminologiesUL-MCCDL-MCCSome examples
WITS Lab, NSYSU.150
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
WITS Lab, NSYSU.151
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
WITS Lab, NSYSU.152
UL Multiplexing and Channel Coding
WITS Lab, NSYSU.153
DL Multiplexing and Channel Coding
WITS Lab, NSYSU.154
Transport Channel Related Terminologies
Transport blockTransport block setTransport block sizeTransport block set sizeTransmission time interval (TTI)Transport formatTransport format setTransport format combinationTransport format combination set
WITS Lab, NSYSU.155
Transport Channel Related Terminologies
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
WITS Lab, NSYSU.156
Transport Channel Related Terminologies
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 }
WITS Lab, NSYSU.157
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 }
Transport Channel Related Terminologies
WITS Lab, NSYSU.158
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}
Transport Channel Related Terminologies
WITS Lab, NSYSU.159
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}
Transport Channel Related Terminologies
WITS Lab, NSYSU.160
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
Transport Channel Related Terminologies
WITS Lab, NSYSU.161
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)
Transport Channel Related Terminologies
WITS Lab, NSYSU.162
UL-MCCCRC attachmentTrBk concatenation / code block segmentationChannel codingRadio frame equalization1st interleavingRadio frame segmentationRate matchingTrCH multiplexingPhysical channel segmentation2nd interleavingPhysical channel mapping
WITS Lab, NSYSU.163
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
WITS Lab, NSYSU.164
UL-MCCTrBk 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
WITS Lab, NSYSU.165
UL-MCCChannel coding
For 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
WITS Lab, NSYSU.166
UL-MCCUsage 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
WITS Lab, NSYSU.167
UL-MCCConcatenation 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
WITS Lab, NSYSU.168
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
WITS Lab, NSYSU.169
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:
WITS Lab, NSYSU.170
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,, =−−=∆ −
WITS Lab, NSYSU.171
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
WITS Lab, NSYSU.172
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
WITS Lab, NSYSU.173
Rate matchingExample: 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
WITS Lab, NSYSU.174
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
WITS Lab, NSYSU.175
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
WITS Lab, NSYSU.176
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
WITS Lab, NSYSU.177
Rate MatchingSince 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
WITS Lab, NSYSU.178
Rate Matching2 solutions in DL-RM
Fixed positionUse 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
WITS Lab, NSYSU.179
Rate Matching
TFCS exampleCombination 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)
WITS Lab, NSYSU.180
Rate MatchingNormal mode
For 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
WITS Lab, NSYSU.181
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
WITS Lab, NSYSU.182
DTX InsertionSince 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
WITS Lab, NSYSU.183
Physical Channel Mapping
One radio frame, Tf = 10 ms
TPC NTPC bits
Slot #0 Slot #1 Slot #i Slot #14
Tslot = 2560 chips, 10*2k bits (k=0..7)
Data2Ndata2 bits
DPDCHTFCI
NTFCI bitsPilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
WITS Lab, NSYSU.184
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
WITS Lab, NSYSU.185
Detail Issues in MCC
But, 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
WITS Lab, NSYSU.186
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
WITS Lab, NSYSU.187
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 io n a lc o d in g R = 1 /3 , 1 /2
R a te m a tc h in 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 in g
1 2
R a d io f r a m es e g m e n ta t io 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 io f r a m ee q u a l i z a t io 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 in c e C R C p a r i ty b i t a t t a c h m e n t fo r 0 b i t t r a n s p o r tb lo c k i s a p p l i e d .
WITS Lab, NSYSU.188
UL 64/128/144 kbps dataT 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 u r b o c o d i n g R = 1 / 3
R a t e m a t c 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 s t i n t e r l e a v i n g
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 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 , 9 )
# 2
R a d i o f r a m es e g m e n t a 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
WITS Lab, NSYSU.189
UL 384 kbps data T r a n s p o r t b l o c k
C R C a t t a c h m e n t
C R C
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 ⎤
1 s t i n t e r l e a v i n g
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
R a t e m a t c h i n g
# 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
WITS Lab, NSYSU.190
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
WITS Lab, NSYSU.191
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
Physical channelmapping
CFN=4N CFN=4N+1 CFN=4N+2 CFN=4N+3
TrCHmultiplexing
WITS Lab, NSYSU.192
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
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
3 * ( N T r C H a + 2 0 ) + N R M a
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 i p l e x i n g
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 .
WITS Lab, NSYSU.193
DL 64/128/144 kbps dataT 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 u r b o c o d i n g R = 1 / 3
R a t e m a t c h i n g
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 s t i n t e r l e a v i n g
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
T o T r C h M u l t i p l e x i n g
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
R a d i o f r a m es e g m e n t a t i o n
# 2( 1 0 5 6 * B + 1 2 * ⎡ B / 9 ⎤ + N R M ) / 2
WITS Lab, NSYSU.194
12.2 kbps + 3.4 kbps data
12.2 kbps data 3.4 kbps data
TrCHmultiplexing
30 ksps DPCH
2nd interleaving
Physical channelmapping
#1#1a #1c
1 2 15
CFN=4Nslot
Pilot symbol TPC
1 2 15
CFN=4N+1slot
1 2 15
CFN=4N+2slot
1 2 15
CFN=4N+3slot
#1b #2#2a #2c#2b #3#1a #1c#1b #4#2a #2c#2b
#1a #2a #1b #2b #1c #2c #1a #2a #1b #2b #1c #2c #1 #2 #3 #4
510 510 510 510
12.2 kbps data