02- owa200003 wcdma radio interface physical layer issue1.0
DESCRIPTION
interfacesTRANSCRIPT
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved
www.huawei.com
Internal
OWA200003 WCDMA Radio Interface
Physical Layer
ISSUE 1.0
HUAWEI TECHNOLOGIES CO., LTD. Page 2All rights reserved
The physical layer offers data transport
services to higher layers.
The access to these services is through the
use of transport channels via the MAC sub-
layer.
The physical layer is expected to perform the
following functions in order to provide the
data transport service, for example
Modulation and spreading/demodulation and
despreading, Inner - loop power control ..etc.
HUAWEI TECHNOLOGIES CO., LTD. Page 3All rights reserved
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
HUAWEI TECHNOLOGIES CO., LTD. Page 4All rights reserved
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 layer
procedures
HUAWEI TECHNOLOGIES CO., LTD. Page 5All rights reserved
Chapter 1 Physical Layer OverviewChapter 1 Physical Layer Overview
Chapter 2 Physical layer key technology Chapter 2 Physical layer key technology
Chapter 3 Physical Layer ProceduresChapter 3 Physical Layer Procedures
HUAWEI TECHNOLOGIES CO., LTD. Page 6All rights reserved
UTRAN Protocol Structure
RNS
RNC
RNS
RNC
Core Network
Node B Node B Node B Node B
Iu Iu
Iur
Iub IubIub Iub
HUAWEI TECHNOLOGIES CO., LTD. Page 7All rights reserved
Radio Interface Protocol Structure
L3
con
tro
l
con
tro
l
con
tro
l
con
tro
l
Logical Channels
Transport Channels
C-plane signaling U-plane information
PHY
L2/MAC
L1
RLC
DCNtGC
L2/RLC
MAC
RLCRLC
RLCRLC
RLCRLCRLC
Duplication avoidance
UuS boundary
BMC L2/BMC
control
PDCPPDCP L2/PDCP
DCNtGC
Radio Bearers
RRC
HUAWEI TECHNOLOGIES CO., LTD. Page 8All rights reserved
Data Processing at Physical Layer
Data from MAC Layer( TB)
Channel coding and multiplexing
Spreading and modulation
HUAWEI TECHNOLOGIES CO., LTD. Page 9All rights reserved
Spreading Technology Spreading consists of 2 steps :
Channelization operation , which transforms data symbols into chips.
Thus increasing the bandwidth of the signal, The number of chips per
data symbol is called the Spreading Factor ( SF ) .The operation is
done by multiplying with OVSF code.
Scrambling operation is applied to the spreading signal .
Data bit
OVSF code
Scrambling code
Chips after spreading
HUAWEI TECHNOLOGIES CO., LTD. Page 10All rights reserved
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)
HUAWEI TECHNOLOGIES CO., LTD. Page 11All rights reserved
Scrambling Code
Scrambling code : GOLD sequence.
Scrambling code period : 10ms ,or 38400 chips.
The code used for scrambling of the uplink
DPCCH/DPDCH may be of either long or short type,
There are 224 long and 224 short uplink scrambling
codes. Uplink scrambling codes are assigned by
higher layers.
For downlink physical channels, a total of 218-1 =
262143 scrambling codes can be generated.
scrambling codes k = 0, 1, …, 8191 are used.
HUAWEI TECHNOLOGIES CO., LTD. Page 12All rights reserved
Scrambling codes for downlink physical channels
Set 0
Set 1
…
Set 511
Primary scrambling code 0
……
Secondary scrambling code 1
Secondary scrambling code 15
Primary scrambling code
511×16
……
Secondary scrambling code 511×1
6+ 15
8192 scrambling codes
512 sets
Primary Scrambling Code
……
A primary scrambling code and 15 secondary scrambling codes are
included in a set.
HUAWEI TECHNOLOGIES CO., LTD. Page 13All rights reserved
Primary Scrambling Code Group
Primary scrambling codes for downlink physical channels
Group 0
…
Primary scrambling code 0
……
Primary scrambling code
8*63
……
Primary scrambling code 63*8+
7
512 primary scrambling codes
……
Group 1
Group 63
Primary scrambling code 1
Primary scrambling code 15
64 primary scrambling code groups
Each group consists of 8 primary scrambling codes
HUAWEI TECHNOLOGIES CO., LTD. Page 14All rights reserved
Chapter 1 Physical Layer OverviewChapter 1 Physical Layer Overview
Chapter 2 Physical layer key technologyChapter 2 Physical layer key technology
Chapter 3 Physical Layer ProceduresChapter 3 Physical Layer Procedures
HUAWEI TECHNOLOGIES CO., LTD. Page 15All rights reserved
Chapter 2 Physical layer key technology Chapter 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
HUAWEI TECHNOLOGIES CO., LTD. Page 16All rights reserved
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 the physical 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 of channel which
uses dedicated carrier frequency, code (spreading code and scramble) and
carrier phase (I or Q) can be regarded as a dedicated channel.
HUAWEI TECHNOLOGIES CO., LTD. Page 17All rights reserved
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
HUAWEI TECHNOLOGIES CO., LTD. Page 18All rights reserved
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)
Common transport channel
Dedicated transport channel
Transport channel
HUAWEI TECHNOLOGIES CO., LTD. Page 19All rights reserved
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
HUAWEI TECHNOLOGIES CO., LTD. Page 20All rights reserved
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 DL shared Channel
Downlink Physical Channel
HUAWEI TECHNOLOGIES CO., LTD. Page 21All rights reserved
Uplink Physical Channel
Uplink Dedicated Physical Channel
Uplink Dedicated Physical Data
Channel (Uplink DPDCH)
Uplink Dedicated Physical Control
Channel (Uplink DPCCH)
Uplink Common Physical Channel
Physical Random Access Channel
(PRACH)
Uplink Physical Channel
HUAWEI TECHNOLOGIES CO., LTD. Page 22All rights reserved
Function of physical channel
Node B UE
P-CCPCH-Primary common control physical channelSCH- Synchronisation Channel
P-CCPCH-Primary common control physical channelSCH- Synchronisation Channel
P-CPICH-Primary common pilot channel S-CPICH-secondary common pilot channelP-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 channel HS-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
HUAWEI TECHNOLOGIES CO., LTD. Page 23All rights reserved
Synchronization Channel (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 code groups of the cell.
SSC is chosen from a set of 16 different codes of length 256, there are altogether 64 primary scrambling code groups.
Primary SCH
Secondary SCH
Slot #0 Slot #1 Slot #14
acsi,0
pac pac pac
acsi,1 acs
i,14
256 chips2560 chips
One 10 ms SCH radio frame
HUAWEI TECHNOLOGIES CO., LTD. Page 24All rights reserved
Common Pilot Channel(CPICH) Common Pilot Channel (CPICH)
Carries pre-defined sequence.
Fixed rate 30Kbps , SF=256
The CPICH uses the same channel and scrambling code but different sequences in the case transmit diversity is used on downlink channel
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
HUAWEI TECHNOLOGIES CO., LTD. Page 25All rights reserved
Common Pilot Channel (CPICH) Primary CPICH
Uses the same 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. Secondary CPICH
An arbitrary channel code of SF=256 is used for S-CPICH S-CPICH is scrambled by either the primary or a secondary scrambling
code There may be zero, one , or several secondary CPICH. S-CPICH may be transmitted over part of the cell S-CPICH may be a phase reference for S-CCPCH and downlink DPCH.
HUAWEI TECHNOLOGIES CO., LTD. Page 26All rights reserved
Primary Common Control Physical Channel (PCCPCH) Fixed rate ( 30kbps , SF=256 ) 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
Data
18 bits
Slot #0 Slot #1 Slot #i Slot #14
1 radio frame: Tf = 10 ms
256 chips
T slot = 2560 chips,20 bits
(Tx OFF)
HUAWEI TECHNOLOGIES CO., LTD. Page 27All rights reserved
Paging Indicator Channel (PICH)
PICH is a fixed-rate (SF=256) physical channel used to carry the Paging Indicators (PI).
PICH is always associated with an S-CCPCH to which a PCH transport channel is mapped.
Frame structure of PICH : one frame of length 10ms consists of 300 bits of which 288 bits a
re 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 p
aging indicator should read the corresponding frame of the associated S-CCPCH.
One radio frame (10 ms)
b1 b0
288 bits for paging indication 12 bits (undefined)
b287 b288 b299
HUAWEI TECHNOLOGIES CO., LTD. Page 28All rights reserved
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.
Data
N bits
Slot #0 Slot #1 Slot #i Slot #14
1 radio frame: Tf = 10 ms
T slot = 2560 chips,
Data
PilotN bitsPilotN bits
TFCI
TFCI
20*2k bits (k=0..6)
HUAWEI TECHNOLOGIES CO., LTD. Page 29All rights reserved
Physical Random Access Channel (PRACH)
The random-access transmission data consists of
two parts:
One or several preambles : each preamble is
of length 4096chips and consists of 256
repetitions of a signature whose length is 16
chips , 16 available signatures totally
10 or 20ms message part
Which signature is available and the length of
message part are determined by higher layer
HUAWEI TECHNOLOGIES CO., LTD. Page 30All rights reserved
PRACH Transmission Structure
Message part Preamble
4096 chips 10 ms (one radio frame)
Preamble Preamble
Message part
Preamble
4096 chips 20 ms (two radio frames)
PreamblePreamble
HUAWEI TECHNOLOGIES CO., LTD. Page 31All rights reserved
PRACH Access Timeslot Structure
#1 #2 #3 #4 #5 #6 #7 #8 #9 #10 #11 #12 #13 #14
5120 chips
radio frame: 10 ms radio frame: 10 ms
Access slot #0 Random Access Transmission
Access slot #1
Access slot #7
Access slot #14
Random Access Transmission
Random Access Transmission
Random Access TransmissionAccess slot #8
HUAWEI TECHNOLOGIES CO., LTD. Page 32All rights reserved
PRACH Message Structure
PilotN bits
Slot # 0 Slot # 1 Slot # i Slot # 14
Message part radio frame TRACH = 10 ms
Tslot = 2560 chips, 10*2
Pilot
TFCI
N bitsTFCI
Data
N data bits Data
Control
k bits (k=0..3)
HUAWEI TECHNOLOGIES CO., LTD. Page 33All rights reserved
Acquisition Indicator Channel (AICH) Frame structure of AICH : two frames, 20 ms , consists of a repeated
sequence of 15 consecutive AS, each of length 20 symbols(5120 chips). Each time slot consists of two parts , an 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
HUAWEI TECHNOLOGIES CO., LTD. Page 34All rights reserved
Uplink Dedicated Physical Channel
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, TFCI , FBI , TPC
HUAWEI TECHNOLOGIES CO., LTD. Page 35All rights reserved
Frame Structure of Uplink DPDCH/DPCCH
Pilot Npilot bits
TPC NTPC bits
Data Ndata bits
Slot #0 Slot #1 Slot #i Slot #14
Tslot = 2560 chips, 10*2k bits (k=0..6)
1 radio frame: Tf = 10 ms
DPDCH
DPCCH FBI
NFBI bits TFCI
NTFCI bits
HUAWEI TECHNOLOGIES CO., LTD. Page 36All rights reserved
Functions of Uplink DPDCH/DPCCH
DCH Data
DPDCHDPDCH
DPCCHDPCCH
Provide control data for DPDCH,such as demodulation, power control, etc
Data bearer Data bearer at physical layerat physical layer
HUAWEI TECHNOLOGIES CO., LTD. Page 37All rights reserved
Downlink Dedicated Physical Channel
DCH consists of dedicated data and control information.
Control information includes : Pilot 、 TPC 、 TFCI(optional).
The spreading factor of DCH can be from 512 to 4,and can be
changed during connection
DPDCH and DPCCH is time multiplexed.
Multi-code transmission within one CCTrCH uses the same
spreading factor. In this case, the DPCH control information is
transmitted only on the first downlink DPCH.
Different CCTrCH can use different spreading factors in the
case there are several CCTrCHs for one UE. In this case
information of only one DPCCH needs to be transmitted.
HUAWEI TECHNOLOGIES CO., LTD. Page 38All rights reserved
Frame Structure of Downlink DPCH
One radio frame, Tf = 10 ms
Slot #0 Slot #1 Slot #i Slot #14
Tslot = 2560 chips, 10*2k bits (k=0..7)
Data2 Ndata2 bits
DPDCH
TFCI NTFCI bits
Pilot Npilot bits
Data1 Ndata1 bits
DPDCH DPCCH DPCCH
TPC NTPC bits
HUAWEI TECHNOLOGIES CO., LTD. Page 39All rights reserved
DCH data
DPDCHDPDCH
DPCCHDPCCH
Provide control data for DPDCH ,such as demodulation, power control,etc.
Data bearer Data bearer at physical layerat physical layer
DCH data
Functions of Downlink DPDCH/DPCCH
HUAWEI TECHNOLOGIES CO., LTD. Page 40All rights reserved
Chapter 2 Physical layer key technology Chapter 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
HUAWEI TECHNOLOGIES CO., LTD. Page 41All rights reserved
{XOR}
Transport Channels
(L1 Characteristics Dependent) PCH BCH FACH RACH DCH
S-CCPCHP-CCPCHPhysical
ChannelsPRACH DPDCH
Logical Channels
(Data Dependent)PCCH
DCCH
DTCH
DecicatedLogicalChannel
CipherOn
BCCH CCCH CTCH
Higher Layer data
PagingPaging
SystemInfoSystem
InfoSignaling
Signaling
CellBroadcast
Service
CellBroadcast
Service
Signalingand
User data
Signalingand
User data
DTCHDTCH
Channel Mapping
HUAWEI TECHNOLOGIES CO., LTD. Page 42All rights reserved
Chapter 1 Physical Layer OverviewChapter 1 Physical Layer Overview
Chapter 2 Physical layer key technology Chapter 2 Physical layer key technology
Chapter 3 Physical Layer ProceduresChapter 3 Physical Layer Procedures
HUAWEI TECHNOLOGIES CO., LTD. Page 43All rights reserved
Synchronization Procedure—Cell Search
Slot synchronization
Frame synchronization and code-group identification
Scrambling-code identification
UE uses PSC to acquire slot synchronization to a cell
UE uses SSC to find frame synchronization and identify the code group of the cell found in the first step
UE determines the primary scrambling code through correlation over the CPICH with all codes within the identified group, and then detects the P-CCPCH and reads BCH information。
HUAWEI TECHNOLOGIES CO., LTD. Page 44All rights reserved
Synchronization Procedure— Channel Timing Relationship
AICH access slo ts
Secondary SCH
Primary SCH
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
Any PDSCH
HUAWEI TECHNOLOGIES CO., LTD. Page 45All rights reserved
Synchronization Procedure—Common Channe Synchronization
Common Channel Synchronization
The following physical channels have the same frame timing : SCH(Primary and secondary)
CPICH(Primary and secondary)
P-CCPCH
PDSCH
P-CCPCH’s radio frame timing is acquired by cell search ( The P-CCPCH on which the cell SFN is transmitted is used as timing reference for all the physical channels )
HUAWEI TECHNOLOGIES CO., LTD. Page 46All rights reserved
Random access procedure START
Choose a RACH sub channel fromavailable 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 Nack
on AICH received
Choose a access slot again
Counter> 0 && Preamble powermaximum allowed power<6 dB
Choose a signature and increase preamble transmit power
Set physical status to be Nack on AICH received
Get negative AI
No AI
Report the physical status to MAC
END
Get positive AI
The counter of preamble retransmit subtract Commanded preamble power
increased by Power Ramp Step1;
N
Y
Send the corresponding message part
HUAWEI TECHNOLOGIES CO., LTD. Page 47All rights reserved
Random Access Procedure—RACH
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 such
that 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
HUAWEI TECHNOLOGIES CO., LTD. Page 48All rights reserved
Random Access Procedure—RACH
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 available RACH sub-channels within the given ASC;
− B: select a signature;
− C: Increase the Commanded Preamble Power;
− D: Decrease the Preamble Retransmission Counter by one. If the Preamble Retransmission Counter > 0 then repeat from step 6. Otherwise exit the physical random access procedure.
HUAWEI TECHNOLOGIES CO., LTD. Page 49All rights reserved
Random Access Procedure—RACH
7. If a negative acquisition indicator corresponding to the
selected 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 the
selected 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
HUAWEI TECHNOLOGIES CO., LTD. Page 50All rights reserved
Transmit diversity Mode
Application of Tx diversity modes on downlink Application of Tx diversity modes on downlink physical channelphysical channel
Physical channel type Open loop mode Closed loop mode
TSTD STTD Mode 1 Mode 2
P-CCPCH – applied – –
SCH applied – – –
S-CCPCH – applied – –
DPCH – applied applied applied
PICH – applied – –
HS-PDSCH – applied applied –
HS-SCCH – applied – –
AICH – applied – –
HUAWEI TECHNOLOGIES CO., LTD. Page 51All rights reserved
Transmit Diversity-STTD
Space time block coding based transmit antenna
diversity(STTD ) 4 consecutive bits b0, b1, b2, b3 using STTD coding
b0 b1 b2 b3
b0 b1 b2 b3
-b2 b3 b0 -b1
Antenna 1
Antenna 2Channel bits
STTD encoded channel bitsfor antenna 1 and antenna 2.
HUAWEI TECHNOLOGIES CO., LTD. Page 52All rights reserved
Transmit Diversity-TSTDTime switching transmit diversity (TSTD) is Time switching transmit diversity (TSTD) is used only on SCH channel.used only on SCH channel.
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)
HUAWEI TECHNOLOGIES CO., LTD. Page 53All rights reserved
Transmit Diversity - Closed Loop Mode
Closed loop mode transmit diversity
Used in DPCH and PDSCH ; Channel coding, interleaving and spreading are done as in non-diversity
mode. The spread complex valued signal is fed to both 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 :
− 1 、 mode 1 uses phase adjustment ; the dedicated pilot symbols of two antennas are different(orthogonal)
− 2 、 mode 2 uses phase/amplitude adjustment ; the dedicated pilot symbols of two antennas are the same.
www.huawei.com
Thank You