002-wcdma radio interface physical layer issue 1
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Internal
WCDMA Radio Interface
Physical Layer
ISSUE 1.0
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The physical layer offers data transport services
to higher layers.
The access to these services is through the use
of transport channels via the MAC sub-layer.
The physical layer is expected to perform the
following functions in order to provide the data
transport service, for example Modulation and
spreading/demodulation and despreading, Inner -
loop power control etc.
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References
TS 25.104 UTRA (BS) FDD Radio Transmission and
Reception
TS 25.201 Physical layer-general description
TS 25.211 Physical channels and mapping of
transport channels onto physical channels (FDD)
TS 25.212 Multiplexing and channel coding (FDD)
TS 25.213 Spreading and modulation (FDD)
TS 25.214 Physical layer procedures (FDD)
TS 25.308 UTRA High Speed Downlink Packet Access
(HSDPA); Overall description; Stage 2
TR 25.877 High Speed Downlink Packet Acces (HSDPA) -Iub/Iur Protocol Aspects
TR 25.858 Physical layer aspects of UTRA High Speed
Downlink Packet Access
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Upon completion of this course, you will be
able to:
Understand radio interface protocol
Architecture
Understand key technology of UMTS
physical layer
Understand UMTS physical layerprocedures
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Chapter 1 Physical Layer OverviewChapter 1 Physical Layer Overview
Chapter 2 Physical layer key technologyChapter 2 Physical layer key technology
Chapter 3 Physical Layer Processing ProcedureChapter 3 Physical Layer Processing Procedure
Chapter 4 Physical Layer ProceduresChapter 4 Physical Layer Procedures
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UTRAN Protocol Structure
RNS
RNC
RNS
RNC
Core Network
Node B Node B Node B Node B
Iu Iu
Iur
Iub IubIub Iub
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Radio Interface Protocol Structure
L3
control
control
control
control
LogicalChannels
TransportChannels
C-plane signaling U-plane information
PHY
L2/MAC
L1
RLC
DCNtGC
L2/RLC
MAC
RLCRLC
RLCRLC
RLCRLC
RLC
Duplication avoidance
UuS boundary
BMC L2/BMC
control
PDCPPDCP L2/PDCP
DCNtGC
RadioBearers
RRC
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Spreading Technology
Spreading consists of 2 steps
Channelization operationwhich transforms data symbols into chips.Thus increasing the bandwidth of the signal, The number of chips per data
symbol is called the Spreading FactorSF.The operation is done bymultiplying with OVSF code.
Scrambling operation is applied to the spreading signal .
Data bit
OVSFcode
Scrambling
code
Chips after
spreading
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Channelization Code
OVSF code is used as channelization code
The channelization codes are uniquely described as Cch,SF,k, where SF is the
spreading factor of the code and k is the code number, 0 k SF-1.
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)
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Scrambling Code
Scrambling codeGOLD sequence.
Scrambling code period : 10ms ,or 38400 chips.
The code used for scrambling of the uplink
DPCCH/DPDCH may be of either long or short type,
There are 224 long and 224 short uplink scrambling
codes. Uplink scrambling codes are assigned by
higher layers.
For downlink physical channels, a total of 218-1 =
262,143 scrambling codes can be generated.
scrambling codes k = 0, 1, , 8191 are used.
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Scrambling
codes for
downlink
physical
channels
Set 0
Set 1
Set 511
Primaryscrambling code 0
Secondaryscrambling code 1
Secondaryscrambling code 15
Primaryscrambling code51116
Secondaryscrambling code
5111615
8192 scramblingcodes
512 sets
Primary Scrambling Code
A primary scrambling code and 15 secondary scrambling codes are
included in a set.
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Primary Scrambling Code Group
Primaryscramblingcodes fordownlinkphysicalchannels
Group 0
Primaryscrambling code 0
Primaryscrambling code8*63
Primaryscrambling code
63*87
512 primaryscrambling codes
Group 1
Group 63
Primaryscrambling code 1
Primary scramblingcode 15
64 primary scramblingcode groups
Each group consists of 8primary scrambling codes
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Chapter 1 Physical Layer OverviewChapter 1 Physical Layer Overview
Chapter 2 Physical layer key technologyChapter 2 Physical layer key technology
Charter 3 Physical layer processing procedureCharter 3 Physical layer processing procedure
Chapter 4 Physical Layer ProceduresChapter 4 Physical Layer Procedures
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Chapter 2 Physical layer key technologyChapter 2 Physical layer key technology
Section 1 Physical ChannelSection 1 Physical Channel Structure and FunctionsStructure and Functions
Section 2 Channel MappingSection 2 Channel Mapping
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WCDMA radio interface has three kinds of channels
In terms of protocol layer, the WCDMA radio interface has three
channels: Physical channel, transport channel and logical channel.
Logical channel: Carrying user services directly. According to the types
of the carried services, it is divided into two types: Control channel and
service channel.
Transport channel: It is the interface of radio interface layer 2 and
physical layer, and is the service provided for MAC layer by thephysical layer. According to whether the information transported is
dedicated information for a user or common information for all users, it
is divided into dedicated channel and common channel.
Physical channel: It is the ultimate embodiment of all kinds of
information when they are transmitted on radio interfaces. Each kind ofchannel which uses dedicated carrier frequency, code (spreading code
and scramble) and carrier phase (I or Q) can be regarded as a
dedicated channel.
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Control channel
Traffic channel
Dedicated traffic channel DTCH
Common traffic channel CTCH
Broadcast control channel BCCH
Paging control channel PCCH
Dedicate control channel DCCH
Common control channel (CCCH
logical channel
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Dedicated Channel (DCH)
-The Dedicated Channel (DCH) is an
uplink or downlink channel.
Broadcast channel (BCH)
Forward access channel (FACH)
Paging channel (PCH)
Random access channel (RACH)
High-speed downlink shared channel
(HS-DSCH)
Common transportchannel
Dedicated transportchannel
Transport channel
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Physical Channel
A physical channel is defined by a specific carrier frequency,
code (scrambling code, spreading code) and relative phase.
In UMTS system, the different code (scrambling code or
spreading code) can distinguish the channels.
Most channels consist of radio frames and time slots, and
each radio frame consists of 15 time slots.
Two types of physical channel:UL and DL
Physical Channel
Frequency,code,phase
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Downlink Physical Channel
Downlink Dedicated Physical Channel
(Downlink DPCH)
Downlink Common Physical Channel
Common Control Physical Channel(CCPCH)
Synchronization Channel (SCH)
Paging Indicator Channel (PICH)
Acquisition Indicator Channel (AICH)
Common Pilot Channel (CPICH)
High-Speed Packet Downlink SharedChannel (HS-PDSCH)
High-Speed Shared Control Channel (HS-SCCH)
DownlinkPhysical Channel
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Uplink Physical Channel
Uplink Dedicated Physical Channel
Uplink Dedicated Physical Data Channel
(Uplink DPDCH)
Uplink Dedicated Physical Control Channel
(Uplink DPCCH)
High-Speed Dedicated Physical Channel (HS-
DPCCH)
Uplink Common Physical Channel
Physical Random Access Channel (PRACH)
Uplink Physical
Channel
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Function of physical channel
Node B UE
P-CCPCH-Primary common control physical channel
SCH- Synchronisation Channel
P-CCPCH-Primary common control physical channel
SCH- Synchronisation Channel
P-CPICH-Primary common pilot channel
S-CPICH-secondary common pilot channel
P-CPICH-Primary common pilot channel
S-CPICH-secondary common pilot channel
Cell broadcast channels
DPDCH-dedicated physical data channelDPDCH-dedicated physical data channel
DPCCH-dedicated physical control channelDPCCH-dedicated physical control channel
Dedicated channels
Paging channels
PICH-paging Indicator ChannelPICH-paging Indicator Channel
S-CCPCH-Secondary common control physical channelS-CCPCH-Secondary common control physical channel
PRACH-Physical random access channelPRACH-Physical random access channel
AICH-Acquisition Indicator ChannelAICH-Acquisition Indicator Channel
Random access channels
HS-DPCCH-High speed dedicated physical control channelHS-DPCCH-High speed dedicated physical control channel
HS-SCCH-High speed share control channelHS-SCCH-High speed share control channel
HS-PDSCH-High speed physical downlink share channelHS-PDSCH-High speed physical downlink share channel
High speed downlink share channels
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Primary Synchronization Channel (P-SCH) Used for cell search
Two sub channels: P-SCH and S-SCH.
SCH is transmitted at the first 256 chips
of every time slot. PSC is transmitted repeatedly in each
time slot.
SSC specifies the scrambling codegroups of the cell.
SSC is chosen from a set of 16
different codes of length 256, thereare altogether 64 primary scramblingcode groups.
PrimarySCH
SecondarySCH
Slot #0 Slot #1 Slot #14
acsi,0
pac pac pac
acsi,1 acs
i,14
256 chips
2560 chips
One 10 ms SCH radio frame
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slot numberScramblingCode Group #0 #1 #2 #3 #4 #5 #6 #7 #8 #9 #10 #11 #12 #13 #14
Group 0 1 1 2 8 9 10 15 8 10 16 2 7 15 7 16
Group 1 1 1 5 16 7 3 14 16 3 10 5 12 14 12 10Group 2 1 2 1 15 5 5 12 16 6 11 2 16 11 15 12
Group 3 1 2 3 1 8 6 5 2 5 8 4 4 6 3 7
Group 4 1 2 16 6 6 11 15 5 12 1 15 12 16 11 2
Group 61 9 10 13 10 11 15 15 9 16 12 14 13 16 14 11
Group 62 9 11 12 15 12 9 13 13 11 14 10 16 15 14 16
Group 63 9 12 10 15 13 14 9 14 15 11 11 13 12 16 10
Secondary Synchronization Channel (S-SCH)
..
2560 chips
acp
Slot # ?
P-SCH acp
Slot #?
16 6S-SCH
acp
Slot #?
11Group 2Slot 7, 8, 9
256 chips
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Common Pilot Channel(CPICH) Common Pilot Channel (CPICH)
Carries pre-defined sequence.
Fixed rate 30Kbps SF=256
Primary CPICH
Uses the fixed channel code--Cch, 256,0
Scrambled by the primary scrambling code
Only one CPICH per cell
Broadcast over the entire cell
The P-CPICH is a phase reference for SCH, Primary CCPCH, AICH,PICH. By default, it is also a phase reference for downlink DPCH.
Pre-defined symbol sequence
Slot #0 Slot #1 Slot # i Slot #14
Tslot = 2560 chips , 20 bits
1 radio frame: Tr = 10 ms
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Primary Common Control Physical Channel (PCCPCH) Fixed rate , fixed OVSF code30kbpsCch,256,1
Carry BCH transport channel
The PCCPCH is not transmitted during the first 256 chips of each time slot.
Only data part STTD transmit diversity may be used
PCCPCH Data
18 bits
Slot #0 Slot #1 Slot #i Slot #14
1 radio frame: Tf
= 10 ms
256 chips
Tslot
= 2560 chips,20 bits
SCH
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Paging Indicator Channel (PICH) PICH is a fixed-rate(SF=256) physical channel used to carry the Paging Indicators (PI).
PICH is always associated with an S-CCPCH to which a PCH transport channel is mapped.
Frame structure of PICHone frame of length 10ms consists of 300 bits of which 288 bits are used to
carry paging indicators and the remaining 12 bits are not defined.
N paging indicators {PI0, , PIN-1} in each PICH frame, N=18, 36, 72, or 144.
If a paging indicator in a certain frame is set to 1, it indicates that UEs associated with this paging
indicator should read the corresponding frame of the associated S-CCPCH.
One radio frame (10 ms)
b1b0
288 bits for paging indication 12 bits (undefined)
b287 b288 b299
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Secondary Common Control Physical Channel (SCCPCH) Carry FACH and PCH.
Two kinds of SCCPCH: with or without
TFCI. UTRAN decides if a TFCI should
be transmitted, UE must support TFCI.
Possible rates are the same as that of
downlink DPCH
SF =256 - 4.
FACH and PCH can be mapped to the
same or separate SCCPCHs. If
mapped to the same S-CCPCH, they
can be mapped to the same fame.
DataN bits
Slot #0 Slot #1 Slot #i Slot #14
1 radio frame: T f = 10 ms
T slot = 2560 chips,
Data
PilotN bitsPilotN bits
TFCITFCI
20*2 k bits (k=0..6)
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Physical Random Access Channel (PRACH)
The random-access transmission data consistsof two parts:
One or several preambleseach preamble
is of length 4096chips and consists of 256
repetitions of a signature whose length is
16 chips16 available signatures totally
10 or 20ms message part
Which signature is available and the length
of message part are determined by higher
layer
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PRACH Transmission Structure
Message partPreamble
4096 chips10 ms (one radio frame)
Preamble Preamble
Message partPreamble
4096 chips 20 ms (two radio frames)
Preamble Preamble
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PRACH Access Timeslot Structure
#1 #2 #3 #4 #5 #6 #7 #8 #9 #10 #11 #12 #13 #14
5120 chips
radio frame: 10 ms radio frame: 10 ms
Access slot #0 Random Access Transmission
Access slot #1
Access slot #7
Access slot #14
Random Access Transmission
Random Access Transmission
Random Access Transmission
Access slot #8
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PRACH Message Structure
Pilot
N bits
Slot # 0 Slot # 1 Slot # i Slot # 14
Message part radio frame TRACH = 10 ms
Tslot = 2560 chips, 10*2
Pilot
TFCI
N bitsTFCI
Data
N
data
bitsData
Control
kbits (k=0..3)
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Acquisition Indicator Channel (AICH)
Frame structure of AICHtwo frames, 20 msconsists of a repeated
sequence of 15 consecutive AS, each of length 20 symbols(5120 chips).
Each time slot consists of two partsan Acquisition-Indicator(AI) and a
part of duration 1024chips with no transmission.
Acquisition-Indicator AI have 16 kinds of Signature.
CPICH is the phase reference of AICH.
AS #14 AS #0 AS #1 AS #i AS #14 AS #0
a1 a2a0 a31 a32a30 a33 a38 a39
AI part Unused part
20 ms
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Uplink Dedicated Physical Channel (DPDCH&DPCCH)
DPDCH and DPCCH are I/Q code multiplexed within each radio
frame
DPDCH carries data generated at Layer 2 and higher layer
DPCCH carries control information generated at Layer 1
Each frame is 10ms and consists of 15 time slots, each time
slot consists of 2560 chips
The spreading factor of DPDCH is from 4 to 256
The spreading factor of DPDCH and DPCCH can be different in
the same Layer 1 connection
Each DPCCH time slot consists of Pilot, TFCIFBITPC
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Frame Structure of Uplink DPDCH/DPCCH
PilotNpilot bits
TPCNTPC bits
DataNdatabits
Slot #0 Slot #1 Slot #i Slot #14
Tslot = 2560 chips, 10*2k bits (k=0..6)
1 radio frame: Tf = 10 ms
DPDCH
DPCCHFBI
NFBI bitsTFCI
NTFCI bits
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Downlink Dedicated Physical Channel (DPDCH+DPCCH)
DCH consists of dedicated data and control information.
Control information includesPilotTPCTFCI(optional). The spreading factor of DCH can be from 512 to 4,and can be
changed during connection
DPDCH and DPCCH is time multiplexed.
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Frame Structure of Downlink DPCH
One radio frame, Tf = 10 ms
Slot #0 Slot #1 Slot #i Slot #14
Tslot = 2560 chips, 10*2kbits (k=0..7)
Data2
Ndata2 bits
DPDCH
TFCI
NTFCI bits
Pilot
Npilot bitsData1
Ndata1 bits
DPDCH DPCCH DPCCH
TPC
NTPC bits
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High-Speed Physical Downlink Shared Channel (HS-PDSCH)
Bear service data and layer2 overhead bits mapped from the transport
channel
SF=16, can be configured several channels to increase data service
Slot #0 Slot#1 Slot #2
T slot= 2560 ch ips , M *10*2 k
bi ts (k=4 )
D a ta N data1bits
1 subfram e: T f= 2 m s
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High-Speed Shared Control Channel (HS-SCCH)
Carries physical layer signalling to a single UE ,such as
modulation scheme (1 bit) ,channelization code set (7 bit),
transport Block size (6bit),HARQ process number (3bit),
redundancy version (3bit), new data indicator (1bit), Ue identity(16bit)
HS-SCCH is a fixed rate (60 kbps, SF=128) downlink physical
channel used to carry downlink signalling related to HS-DSCH
transmission
S lo t # 0 S l o t # 1 S lo t # 2
T s l o t = 2 5 6 0 c h i p s , 4 0 b i t s
D a t a
N d a t a 1 b i t s
1 s u b f r a m e : T f= 2 m s
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High-Speed Dedicated Physical Control Channel (HS-DPCCH )
HS-DPCCH carries information to acknowledge downlink transport
blocks and feedback information to the system for scheduling and link
adaptation of transport block
CQI and ACK/NACK
Physical Channel ,Uplink, SF=256,power control
S u b f ra m e # 0 S u b f ra m e # i S u b f ra m e # 4
H A R Q - A C K C Q I
O n e r a d i o f r a m e T f = 1 0 m s
O n e H S - D P C C H s u b f r a m e ( 2 m s )
2 T s l o t = 5 1 2 0 c h i p sT s l o t = 2 5 6 0 c h i p s
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Chapter 2 Physical layer key technologyChapter 2 Physical layer key technology
Section 1 Physical Channel Structure and FunctionsSection 1 Physical Channel Structure and Functions
Section 2 Channel MappingSection 2 Channel Mapping
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Mapping Between ChannelsLogical channels Transport channels Physical channels
BCCH BCH P-CCPCH
FACH S-CCPCH
PCCH PCH S-CCPCH
CCCH RACH PRACH
FACH S-CCPCH
CTCH FACH S-CCPCH
DCCH, DTCH DCH DPDCH
HS-DSCH HS-PDSCH
RACH, FACH PRACH, S-CCPCH
Setting Common Channel Powers
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RBS
FACH (control): default =18 (1.8 dB)
Paging channel: default =-0.4 dB
Paging indication ch: default =-7 (-7 dB)
Primary SCH: default =-18 (-1.8 dB)
Secondary SCH: default =-35 (-3.5 dB)
FACH (traffic): default =15 (1.5 dB)
PCPICH: default = 300(30 dBm)
Broadcast Channel: default = -31 (-3.1 dB)
AICH: default = -6 (-6 dB)
HS-SCCH: default =2 (2 dB)
Setting Common Channel Powers
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Chapter 1 Physical Layer OverviewChapter 1 Physical Layer Overview
Chapter 2 Physical layer key technologyChapter 2 Physical layer key technology
Charter 3 Physical layer processing procedureCharter 3 Physical layer processing procedure
Chapter 4 Physical Layer ProceduresChapter 4 Physical Layer Procedures
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Chapter 3 Physical Layer Processing ProcedureChapter 3 Physical Layer Processing Procedure
Section 1 Coding and multiplexing technologySection 1 Coding and multiplexing technology
Section 2 Spreading technologySection 2 Spreading technology
Section 3 Modulation technologySection 3 Modulation technology
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CRC of TB
Error detection is provided on transport blocks through a Cyclic
Redundancy Check (CRC)
CRC size is informed by higher layer signal
08121624(optional)
If no TB are input, no CRC bits should be attached. If TB are
input with TB SIZE=0,CRC bits shall be also added ,but all
CRC are zero
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TB Concatenation and Code Block Segmentation
All transport blocks in a TTI are serially concatenated .
The maximum size of the code blocks depends on whetherconvolutional coding or turbo coding is used for the TrCH .
Convolutional code: if TBS SIZE>504,segmented to multiple code
block of the same size.
Turbo code:if TBS SIZE>5114, segmented to multiple code block
of the same size.
No coding:no segmentation
If codes cannot be segmented evenly, fill in 0 bits at the
beginning of the first code block.
If the code block length of Turbo code
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Channel coding
The following channel coding schemes can be applied to TrCHs:
Convolutional coding, coding rates 1/3 and 1/2 are defined
Turbo coding, The coding rate of Turbo coder is 1/3
No coding
Usage of coding
BCHPCH and RACH1/2 Convolutional coding
DCH and FACH1/2or1/3 Convolutional coding ,1/3Turbo
coding, no coding
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Rate Matching
Rate matching means that bits on a transport channel are
repeated or punctured.
The number of bits on a transport channel can vary between
different transmission time intervals(TTI). In the downlink the
transmission is interrupted if the number of bits is lower than
maximum. When the number of bits between different
transmission time intervals in uplink is changed, bits are
repeated or punctured to ensure that the total bit rate after
TrCH multiplexing is identical to the total channel bit rate of the
allocated dedicated physical channels.
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Interleaving
Functionreduce the influence of fast fading.
Two kinds of interleaving1st interleaving and 2nd
interleaving
The length of 1st interleaving is TTI of TrCH, 1stinterleaving is a inter-frame interleaving
The length of 2nd interleaving is a physical frame , 2nd
interleaving is a intra-frame interleaving.
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Radio Frame Segmentation
When the transmission time interval (TTI) is longer than 10 ms,
the input bit sequence is segmented and mapped ontoconsecutive Fi radio frames.
Following radio frame size equalisation in the UL the input bit
sequence length is guaranteed to be an integer multiple of Fi.
Following rate matching in the DL the input bit sequence length
is guaranteed to be an integer multiple of Fi.
Fi:Number of radio frames in the transmission time interval of
TrCH i.
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Multiplexing of TrCH Every 10 ms, one radio frame from each TrCH is delivered to
the TrCH multiplexing. These radio frames are serially
multiplexed into a coded composite transport channel
(CCTrCH)
The format of CCTrCH is indicated by TFCI
TrCH can have different TTI before multiplexing
2 types of CCTrCH:Common and dedicated
Common CCTrCH should be multiplexed by common TrCH;
Dedicated CCTrCH should be multiplexed by dedicated
TrCH
There is only one CCTrCH in uplink and one or several
CCTrCH in downlink for one user
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Insertion of discontinuous transmission (DTX)indication bits
In the downlink, DTX is used to fill up the radio frame with bits.
DTX indication bits only indicate when the transmission should
be turned off, they are not transmitted.
1st insertion of DTX indication bits
This step of inserting DTX indication bits is used only if thepositions of the TrCHs in the radio frame are fixed
2nd insertion of DTX indication bits
The DTX indication bits inserted in this step shall be placed
at the end of the radio frame.
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Physical Channel Segmentation and Mapping
When multiple physical channels are used, one CCTrCH radio frame
can be divided into multiple physical frames multicode transmission
Each physical channel of multicode transmission must have the same
SF
DPCCH and DPDCH of uplink physical channel is code multiplexed.
DPCCH and DPDCH of downlink physical channel is time multiplexed
Uplink physical channel must be fully filled except when cpmpressed
mode is used
In downlink, the PhCHs do not need to be completely filled with bits
that are transmitted over the air. Values correspond to DTX indicators,
which are mapped to the DPCCH/DPDCH fields but are not
transmitted over the air.
Transport channel multiplexing structure for downlinkTransport channel multiplexing structure for downlink
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10 20 40 or 80ms
data
data
data
TrCH-i
dataCRC dataCRC dataCRC
dataCRCdataCRC dataCRCd a t aCBL CBL CBL
0 8 16 or 24bits
Size Z
512 Ktail Conventional code
5120 Ktail Turbo code
CedBL CedBL CedBLCoded data Channel CodingRate matched data
Rate matched data DTXor
or
Data before 1st interleavingData after 1st interleaved
Radio frame Radio frame Radio frame
Number of Rado frame 1 2 4 or 8
TrCH-1 TrCH-2 TrCH-ICCTrCHTrCH-1 TrCH-2 TrCH-I DTXCCTrCH
Ph-1 Ph-2 Ph-P
10ms
10msPh-1 Ph-2 Ph-P
TPC TFCI pilot
Spreading
ScramblingSpreading
Scrambling
Spreading
Scrambling
TrCH-i+1
data1 data2 TPC TFCI pilotdata1 data2 TPC TFCI pilotdata1 data2
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Example of Coding and Multiplexing
The number of TrChs 3
Transport block size 81, 103, and 60 bitsCRC 12 bits (attached only to TrCh#1)
Coding CC, coding rate = 1/3 for TrCh#1, 2 coding rate =1/2 for TrCh#3
TTI 20 ms
Transport block size 148 bits
Transport block set size 148 bits
CRC 16 bits
Coding CC, coding rate = 1/3
TTI 40 ms
Parameters for
12.2kb/s AMR speech
Parameters for
3.4kb/s control channel
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Example of Coding and Multiplexing
TrCh#1Transport blockC R C a tt ac h m e n t
C R C
Tail bi t a ttachmen t
Convolu t iona lcoding R= 1/3 , 1 /2
Rate m atch ing
8 1
81
3 03
Tail
89 3
3 0 3 + N RM 11 st inter leaving
1 2
Radio f ramesegmentat ion
# 1 a
To TrCh M ult iplexing
3 0 3 + N RM 1
N RF 1 = (303 +N RM 1)/ 2
N RF 2 = (333+ N RM 2)/ 2
N RF 3 = (136+ N RM 3)/ 2
# 1 b
TrCh#2
1 03
10 3
33 3
Tail
81 03
3 3 3 + N RM 2
# 2 a
TrCh#3
6 0
60
13 6
Tail
860
1 3 6 + N RM 3
# 3 a 136 +N R M 3
# 3 b 3 3 3 + N RM 2
# 2 b N RF 1 N R F1 N RF 2 N RF 2 N R F3 N RF 3
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Example of Coding and Multiplexing(3.4kbps) T r a n s p o r t b l o c k
C R C a t t a c h m e n t
C R C
C o n v o l u t i o n a lc o d i n g R = 1 / 3
R a t e m a t c h i n g
1 4 8
1 4 8
5 1 6 * B
T a i l
8 * B
( 5 1 6 + N R M ) * B
1s t
i n t e r l e a v i n g
1 6 b i t s
R a d i o f r a m es e g m e n t a t i o n
# 1
[ ( 1 2 9 + N R M ) * B + N D I ] /4
T o T r C h M u l t i p l e x i n g
( 5 1 6 + N R M ) * B + N D I
# 2 # 4
T a i l b i t a t t a c h m e n t
1 6 4 * B
# 3
T r B k c o n c a t in a t io n B T r B k s ( B = 0 , 1 )
1 6 4 * B
( 5 1 6 + N R M ) * B + N D I
I n s e r t io n o f D T Xi n d i c a t i o n *
[ ( 1 2 9 + N R M ) * B + N D I ] /4 [ ( 1 2 9 + NR M ) * B + N D I ] /4 [ ( 1 2 9 + N
R M ) * B + N D I ] /4
* I n s e r t i o n o f D T X i n d i c a t io n i s u s e d o n l y i f t h e p o s i t i o n o f t h e T r C H s i n t h e r a d i o f r a m e i s f i x e d .
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Example of Coding and Multiplexing
12.2 kbps data 3.4 kbps data
TrCHmultiplexing
30 ksps DPC
2nd interleaving
Physical channelmapping
#1#1a #1c
1 2 15
CFN=4Nslot
Pilot symbol TPC
1 2 15
CFN=4N+1slot
1 2 15
CFN=4N+2slot
1 2 15
CFN=4N+3slot
#1b #2#2a #2c#2b #3#1a #1c#1b #4#2a #2c#2b
#1a #2a #1b #2b #1c #2c #1a #2a #1b #2b #1c #2c #1 #2 #3 #4
510 510 510 510
12.2 kbps data
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Chapter 3 Physical Layer Processing ProcedureChapter 3 Physical Layer Processing Procedure
Section 1 Coding and multiplexing technologySection 1 Coding and multiplexing technology
Section 2 Spreading technologySection 2 Spreading technology
Section 3 Modulation technologySection 3 Modulation technology
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Uplink DPCCH/DPDCH Spreading The DPCCH is always spread by code cc = Cch,256,0
When only 1 DPDCH exists,(Cd,1 = Cch,SF,k ) k=SF/4
The code used for scrambling of the uplink DPCCH/DPDCH may be of either longor short type
I
j
c d , 1 d
S l o n g , n o r S s h o r t , n
I + j Q
D P D C H 1
Q
c d , 3 d
D P D C H 3
c d , 5 d
D P D C H 5
c d , 2 d
D P D C H 2
c d , 4 d
D P D C H 4
c d , 6 d
D P D C H 6
c c c
D P C C H
Up to 6 DPDCH
for one user
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Uplink PRACH Spreading
Message part is shown in the following figurethe value of
gain factors is the same with DPDCH/DPCCH
ccc
cd d
Sr-msg,n
I+jQ
PRACH message
control part
PRACH message
data partI
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Downlink Spreading
Downlink physical channel except SCH is first serial-to-parallel
converted , spread by the spreading code, and then scrambled by a
complex-valued scrambling code.
The beginning chip of the scrambling code is aligned with the frame
boundary of P-CCPCH.
Each channel have different gain factor
I
Data ofphysical
channel
except
SCH
SP
Cch,SF,m
Sdl,n
Q
I+jQ S
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Downlink Spreading
Different physical
annel come from point S
G1
G2
GP
GS
S-SCH
P-SCH
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Chapter 3 Physical Layer Processing ProcedureChapter 3 Physical Layer Processing Procedure
Section 1 Coding and multiplexing technologySection 1 Coding and multiplexing technology
Section 2 Spreading technologySection 2 Spreading technology
Section 3 Modulation technologySection 3 Modulation technology
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Uplink Modulation The chip rate is 3.84Mbps
In the uplink, the complex-valued chip sequence generated by thespreading process is QPSK modulated
S
Im{S}
Re{S}
cos(t)
Complex-valuedsequenceafterspreading
-sin(t)
Split
real &imagparts
Pulse
shaping
Pulseshaping
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Downlink Modulation The chip rate is 3.84Mbps
In the downlink, the complex-valued chip sequence generatedby the spreading process is QPSK modulated
S
Im{S}
Re{S}
cos(t)
Complex-valuedsequenceafterspreading
-sin(t)
Split
real &imagparts
Pulse
shaping
Pulseshaping
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Chapter 1 Physical Layer OverviewChapter 1 Physical Layer Overview
Chapter 2 Physical layer key technologyChapter 2 Physical layer key technology
Charter 3 Physical layer processing procedureCharter 3 Physical layer processing procedure
Chapter 4 Physical Layer ProceduresChapter 4 Physical Layer Procedures
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Synchronization ProcedureCell Search
Frame synchronization and
code-group identification
Scrambling-codeidentification
UE uses SSC to find framesynchronization and identify thecode group of the cell found inthe first step
UE determines the primaryscrambling code through correlationover the CPICH with all codes within
the identified group, and then detectsthe P-CCPCH and reads BCHinformation
Slot synchronization
UE uses PSC to acquire slotsynchronization to a cell
Synchronization Procedure Channel Timing Relationship
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AICH accessslots
SecondarySCH
PrimarySCH
S-CCPCH,k
10 ms
PICH
#0 #1 #2 #3 #14#13#12#11#10#9#8#7#6#5#4
P -CCPCH, (SFN modulo 2) = 0 P -CCPCH, (SFN modulo 2) = 1
Any CPICH
k:th S -CCPCH
PICH for k:th S -CCPCH
n:th DPCH DPCH,n
Random access procedure
START
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a do access p ocedu eChoose a RACH sub channel from
available ones
Get available signatures
Set Preamble Retrans Max
Set Preamble _Initial _ Power
Send a preamble
Check the corresponding AI
Increase message part power by p-m based on preamble power
Set physical status to be RACH
message transmitted Set physical status to be Nackon AICH received
Choose a access slot again
Counter> 0 & Preamble power-maximum allowed power
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Random Access ProcedureRACH Physical random access procedure
1. Derive the available uplink access slots, in the next full access
slot set, for the set of available RACH sub-channels within the
given ASC. Randomly select one access slot among the ones
previously determined. If there is no access slot available in the
selected set, randomly select one uplink access slot corresponding
to the set of available RACH sub-channels within the given ASC
from the next access slot set. The random function shall be suchthat each of the allowed selections is chosen with equal
probability
2. Randomly select a signature from the set of available signatures
within the given ASC.
3. Set the Preamble Retransmission Counter to Preamble_
Retrans_ Max
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Random Access ProcedureRACH 4. Set the parameter Commanded Preamble Power to
Preamble_Initial_Power
5. Transmit a preamble using the selected uplink access slot,
signature, and preamble transmission power.
6. If no positive or negative acquisition indicator (AI +1 nor 1)
corresponding to the selected signature is detected in the downlink
access slot corresponding to the selected uplink access slot:
A: Select the next available access slot in the set of availableRACH sub-channels within the given ASC;
B: select a signature;
C: Increase the Commanded Preamble Power;
D: Decrease the Preamble Retransmission Counter by one. Ifthe Preamble Retransmission Counter > 0 then repeat from
step 6. Otherwise exit the physical random access procedure.
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Random Access ProcedureRACH
7. If a negative acquisition indicator corresponding to theselected signature is detected in the downlink access slot
corresponding to the selected uplink access slot, exit the
physical random access procedure Signature
8. If a positive acquisition indicator corresponding to theselected signature is detected , Transmit the random
access message three or four uplink access slots after the
uplink access slot of the last transmitted preamble
9. exit the physical random access procedure
Transmit diversity Mode
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Transmit diversity Mode
Application of Tx diversity modes on downlink physical channelApplication of Tx diversity modes on downlink physical channel
appliedAICH
appliedHS-SCCH
appliedappliedHS-PDSCH
appliedPICH
appliedappliedappliedDPCH
appliedS-CCPCH
appliedSCH
appliedP-CCPCH
Mode 2Mode 1STTDTSTDClosed loop modeOpen loop modePhysical channel type
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Transmit Diversity-STTD
Space time block coding based transmit antenna diversity(STTD
4 consecutive bits b0, b1, b2, b3 using STTD coding
b0 b1 b2 b3
b0 b1 b2 b3
-b2 b3 b0 -b1
Antenna 1
Antenna 2
Channel bits
STTD encoded channel bitsfor antenna 1 and antenna 2.
Transmit Diversity-TSTD
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Transmit Diversity TSTD
Time switching transmit diversity (TSTD) is used only on SCH chaTime switching transmit diversity (TSTD) is used only on SCH channel.nnel.
Antenna 1
Antenna 2
ac si,0
acp
acsi,1
acp
acsi,14
acp
Slot #0 Slot #1 Slot #14
acsi,2
acp
Slot #2
(Tx OFF) (Tx OFF)(Tx OFF)
(Tx OFF)
(Tx OFF)
(Tx OFF)(Tx OFF)(Tx OFF)
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Closed Loop Mode
Transmit DiversityClosed Loop Mode Closed loop mode transmit diversity
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p y
Used in DPCH and PDSCH
Channel coding, interleaving and spreading are done as in non-
diversity mode. The spread complex valued signal is fed to both TX
antenna branches, and weighted with antenna specific weight
factors w1 and w2.
The weight factors are determined by the UE, and signalled to the
UTRAN access point (=cell transceiver) using the D-bits of the FBI
field of uplink DPCCH.
The calculation of weight factor is the key point of closed loop Tx
diversity.there are two modes with different calculation methods of
weight factor
1mode 1 uses phase adjustmentthe dedicated pilot
symbols of two antennas are different(orthogonal)
2mode 2 uses phase/amplitude adjustment the dedicated
pilot symbols of two antennas are the same.
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