1、TD-SCDMA,吴伟民 电子与信息工程系 ,1,TD-SCDMA,Evolution Path,TD-SCDMA: Frequency Band,TD-SCDMA Vs W-CDMA,System Paramters,Frame Structure,Physical Channels,Synchronization Channels Downlink Synchronization Uplink Synchronization Multiplexing Channels Joint Detection Baton Handover N-Frequency Cell,TD-SCDMA Evol
2、ution Path3GPP,LCR TDD （R4）,LCR TDD （R5）,LCR TDD (R6),LCR TDD (R7),LTE TDD,CCSA China Communications Standards,TD-SCDMA Stage III （R7）,OFDM/SC-FDMA,Association,TD-SCDMA Stage I （R4 2003/03）N FrequencyCell,TD-SCDMA Stage II （R5）Multi-carrier,Standardization,2006,Short Term Evolution2008,Long Term Evo
3、lution,TD-SCDMA: Frequency Band,1755 1785,1850 1880,1920,1980 2010 2025,2110,2170 2300,2400,Satellite,Satellite,30 MHz,60 MHz,40 MHz,15 MHz,100 MHz,FDD,TDD,TD-SCDMA Vs W-CDMA,CodeC3C2,Frequency,User 3User 2User 1,C1,CDMA,Time,1 userW-CDMA,1 Code,Spreading Factor Max,512 Codes,TD-SCDMA,Spreading Fact
4、or Max,16 Codes,TD SCDMA Vs W-CDMA,code,time,User 1,User 2,W-CDMA,UL,DL,frequency,5 MHz,190 MHzcode,time16code,TD-SCDMA,frequency,can be used,TD SCDMA Vs W-CDMA,3 simultaneous technologies,TD SCDMA Vs W-CDMA,Avantages of TD-SCDMA:, Efficient spectrum allocation, Support for asymmetric traffic and se
5、rvices, Equivalent Channel in the Uplink and Downlink (Fading and multi-path ) Elimination of intra-cell and inter-cell interference. Low power consumption Baton handover, Low cost for the RF front end,Disdavantages of TD-SCDMA:, Requires accurate synchronization,Limited support for high speed/mobil
6、ity users Complex and expensive technologies,7,TD SCDMA System Parameters,ParameterCarrier bandwidthCarrier spacingChip rateDuplex typeMultiple access schemeFrame lengthNumber of slots/sub-framesRadio frame lengthRadio-subframe lengthData modulationVoice data rateReceiverSpreading factorsMax data ra
7、te per user (theoretical)SynchronizationAntenna processing,Value1.6 MHz1.6 MHz1.28 McpsTDDTDMA, CDMA, FDMA10 ms10 ms5 msQPSK or 8-PSK8 Kbit/sJoint detector (rake in UE)1, 2, 4, 8 and 162 MbpsDownlink and uplinkSmart antenna with beam forming,TD SCDMA: Frame StructureChip rate: 1.28 Mcps,10ms Radio f
8、rame #i5ms,Radio frame #i+15ms,Bandwidth: 1.6 MHzModulation: QPSK/8PSK/16QAMDuplex: TDDDwPTS : Downlink Pilot TimeSlot (96 chips),Sub-frame #1 Sub-frame #2,UpPTS : Uplink Pilot TimeSlot (160 chips),DwPTS GP1,UpPTS,TS0,TS1,TS2,TS3,TS4,TS5,TS6,352 chipsData 1,144 chipsMidamble,352 chipsData 2,GP3,16 c
9、hips,First Switch Point: GP1 (96 chips), Second Switch Point: after TS1,DL,UL,UL/DL,GP,GP,16,CP,-,-,TD SCDMA: Physical ChannelDPCH: Dedicated Physical Channel, Rec 25.221 5A.2Burst structure of the traffic burst format,Data symbols352 chips,Midamble 144 chips,Data symbols352 chips,864*Tc16 SF= 16 co
10、de channel per timeslot per Carrier,Spreading factor (Q)124816,Number of symbols (N) per data field in Burst352176884422,The contents of the traffic burst format fields,Chip number(CN)0-351352-495496-847848-863,Length of field inchips35214435216,Length of field insymbolscf table 8Acf table 8A,Conten
11、ts offield Data symbolsMidamble Data symbols Guard period,1,st,2,3,P,P,3,1,st,rd,P,P,TD SCDMA: Physical ChannelDPCH: Transmission of TFCI, Rec 25.221 5A.2.2.1Position of the TFCI code word in the traffic burst in case of no TPC and SS,part of,TFCI code word,nd,part of,TFCI code word,rd,part of,TFCI
12、code word,4 th part of,TFCI code word,G,G,Data symbols,Midamble,Data symbols,Data symbols,Midamble,Data symbols,Time slot x (864 Chips)Sub-frame 5ms,Time slot x (864 Chips)Sub-frame 5ms,Radio Frame 10msPosition of the TFCI code word in the traffic burst in case of TPC and SS,part of TFCI code word,S
13、S,TPC symbols,symbols2 nd part of TFCI code word,part of TFCI code wordSS symbols,TPC,symbols4 th part of TFCI code word,G,G,Data symbols,Midamble,Data symbols,Data symbols,Midamble,Data symbols,Time slot x (864 Chips),Time slot x,(864 Chips),Sub-frame 5ms,Radio Frame 10ms,Sub-frame 5ms,GP,0,1,TD SC
14、DMA: Physical ChannelDPCH: Transmission of TPC / SS, Rec 25.221 5A.2.2.2Position of TPC information in the traffic burst in downlink and uplink,SS symbol(s),TPC symbol(s),Data symbols,Midamble,Data symbols,144 chips864 ChipsCoding of the SS for QPSK,TPC Bit Pattern for BPSK,SS Bits,SS command,Meanin
15、g,bTPC,TPC,Meaning,00,Down,Decrease synchronisation shift by k/8,command,Tc,DownUp,Decrease Tx Power Increase Tx Power,11 01,Up Do nothing,Increase synchronisation shift by k/8 Tc No change,TPC Bit Pattern for 8PSK,Coding of the SS for 8PSK,TPC Bits000110,TPC commandDownUp,Meaning Decrease Tx Power
16、Increase Tx Power,SS Bits000,SS commandDown,Meaning Decrease synchronisation shift by k/8 Tc,110 011,Up Do nothing,Increase synchronisation shift by k/8 Tc No change,The SS is utilised to command a timing adjustment by (k/8) Tc each M sub-frames, where Tc is the chip period. The k and M values are s
17、ignalled by the network.,field(1),TD SCDMA: Physical Channel,DPCH: Timeslot Formats Rec 25.221 5A.2.4.1Time slot formats for the DownlinkQPSKTime slot formats for the Uplink,Slot Format#012222324Slot Format#01210254069,SpreadingFactor161616111SpreadingFactor1616168421,Midamblelength(chips)1441441441
18、44144144Midamblelength(chips)144144144144144144144,NTFCI code word(bits)04881632NTFCIcode word(bits)04800032,NSS & NTPC(bits)0&00&00&032 & 3232 & 3232 & 32NSS &NTPC(bits)0&00&00&00&00&00&032 &,Bits/slot888888140814081408Bits/slot8888881763527041408,NData/Slot(bits)888684134013361328NData/Slot(bits)8
19、886841763527041328,Ndata/data(bits)444242702700696Ndata/data(bits) field(1)44424288176352696,Ndata/datafield(2)(bits)444442638636632Ndata/datafield(2)(bits)44444288176352632,32,t,TD SCDMA: Physical ChannelDPCH: Timeslot Formats Rec 25.221 5A.2.4.2,Slot,Spreading,Midamble,NTFCI,NSS &,Bits/slo,NData/S
20、lot,Ndata/data,Ndata/data,8PSK,Format#,Factor,length (chips),code word(bits),NTPC (bits),(bits),field(1) (bits),field(2) (bits),0 1 2,1 1 1,144 144 144,06 12,0&0 0&0 0&0,2112 2112 2112,2112 2109 2106,1056 1053 1053,1056 1056 1053,Time slot formats for theDownlink & Uplink,2021222324,1616161616,14414
21、4144144144,06122448, 3&3 3&3 3&3 3&3 3&3,132132132132132,126123120114102,6663636054,6060575448,1,2,TD SCDMA: Physical ChannelP-CCPCH: Primary common control physical channel, Rec 25.221 5A.3.1Common Transport Channels is mapped onto thePrimary Common Control Physical Channels (P-CCPCH1 and P-CCPCH2)
22、The P-CCPCHs are mapped onto the first two code channels of timeslot#0 with spreading factor of 16,cQk=16 cQk=16,BCH,Data symbols352 chips,Midamble 144 chips,Data symbols352 chips,GP 16 CP,864*TcNo TFCI is applied for the P-CCPCH,1,st,2,P,-,GP,16,CP,TD SCDMA: Physical ChannelS-CCPCH: Secondary Commo
23、n Control Physical channel, Rec 25.221 5A.3.1The time slot and codes used for the S-CCPCH are broadcast on the BCHIn a multi-frequency cell S-CCPCH shall be transmitted only on the primaryfrequency,part of TFCI code word,nd,part of TFCI code word,G,Data symbols,MidambleTime slot x (864 Chips),Data s
24、ymbols,TFCI is applied for the S-CCPCH,Fixed SF = 16,Data symbols352 chips,Midamble 144 chips,Data symbols352 chips,864*TcNo TFCI is applied for the S-CCPCH,TD SCDMA: Physical ChannelPRACH: Physical Random Access CHannel, Rec 25.221 5A.3.4The RACH is mapped onto one or more uplink physical random ac
25、cess channels (PRACH).In such a way the capacity of RACH can be flexibly scaled depending on the operators need.,Data symbols352 chips,Midamble 144 chips,Data symbols352 chips,GP 16 CP,864*TcPRACH timeslot formats,SpreadingFactor1684,Slot Format#01025,In a multi-frequency cell the PRACH shall be tra
26、nsmitted only on the primary frequency.,11,2,9 (LSB),7,GP,16,CP,TD SCDMA: Physical ChannelFPACH: Fast Physical Access Channel, Rec 25.221 5A.3.3The FPACH is used for the acknowledgement of a detected signature with timing and power level adjustment indication to an user equipment.FPACH makes use of
27、one code with spreading factor 16, so that its burst is composed by 44 symbols. The spreading code, training sequence and time slot position are configured by the network and signalled on the BCH.In a multi-frequency cell the FPACH is transmitted on the primary frequency. The FPACH may also be also
28、transmitted on the secondary frequency in case of handover.,FPACH information 32 bits descriptionInformation field Length (in bits) Signature Reference Number 3 (MSB) Relative Sub-Frame Number Received starting position of the UpPCH (UpPCHPOS) Transmit Power Level Command for RACH message Reserved b
29、its (default value: 0),Signature Reference Number : bit sequence(0 0 0) corresponds to the first signature of the cell; ; bit sequence (1 1 1) corresponds to the 8th signature of the cell.Relative Sub-Frame : bit sequence (0 0) indicates one sub-frame difference; ; bit sequence (1 1) indicates 4 sub
30、-frame differenceReceived starting position of the UpPCH: range 0 8191Transmit power level command is transmitted in 7 bits,Data symbols352 chips,Midamble 144 chips864*Tc,Data symbols352 chips,The FPACH uses slot format #0, SF=16,TD SCDMA: Physical ChannelsSynchronisation Channels, Rec 25.221 5A.3.5
31、,DwPTS(75us),GP1(75us),UpPTS (125us),GP2,SYN C_DL,SYNC_UL,GP2,TS0,(32chips),(64chips),(128chips),(32chips),TS1,DwPCH: Downlink Pilot Channel32 SYNC_DL avalaible codes 1 cell SYNC_DL code,UpPCH: Uplink Pilot Channel256 SYNC_UL codes32 Groups, 8 codes per group,In a multi-frequency cell the DwPCH shal
32、l be transmitted only on the primaryfrequency.The UpPCH is transmitted on the primary frequency. The UpPCH may also be transmitted on the secondary frequencies in case of handover.,( ),codes,S1,S2,0,1,2,3,TD SCDMA: Synchronization ChannelsDownlink Pilot CHannel, Rec 25.223 8.1For the generation of t
33、he complex valued SYNC-DL codes of length 64, the basic binary SYNC-DLs = S 1, s 2 ,. , s 64SYNC-DL is QPSK modulated and the phase of the SYNC-DL is used to signal the presence ofthe P-CCPCH .The SYNC-DL code is not scrambled.Four consecutive phases (phase quadruple) of the SYNC-DL are used to indi
34、cate thepresence of the P-CCPCH in the following 4 sub-framesSequences for the phase modulation for the SYNC-DL,Name,Phase quadruple 135, 45, 225, 135,Meaning There is a P-CCPCH in the next 4 sub-frames,Table AA.1: 32 Basic SYNC-DL Codes,315, 225, 315, 45,There is no P-CCPCH in the next 4 sub-frames
35、,Code ID,SYNC-DL Codes of,length 64 B3A7CC05A98688E49D559BD290606791 2CE7BA12A017C3A234511D20672F4712,. 28 29 30 31, D4354B2FE02361CC 5383AB6C8A10CE84D417A730F2F12244 ABF0A0D905A939C4,s,0,1,2,3,4,5,6,251,252,253,254,255,TD SCDMA: Synchronization ChannelsUplink Pilot CHannel, Rec 25.223 8.2UpPCH : ge
36、neration of the complex valued SYNC-UL codes of length 128s = ( 1, s 2 ,. , s128)Table AA.2: 256 Basic SYNC-UL Codes,Code ID,SYNC-UL Codes of length 128 C11C20F0D1807DB8859175B798EC094A 91278068081EC8E74543DBC1C9AD4235 38F5AEE2E513DB12A663BA04160103E5 7AA8A0A210F12A1E4332F2EDD33011FC C180EA3B9BA1774
37、EB9611BD249C4A508 B072A2C839489D496B98CE9D0132FBC9B2723EAC6EB01667F2B33961C8074234. 68FC090C2221AA98BF0D24E85066EFC2 9E26CEC67832FC42A87E92FA1015212EACD889634F79506F2582EA03240F2A07 AA65407E1F4A33BF9A62860A3D6A4CC0 B1B950AC76A608AA32D04B03C7FF24D3,TD SCDMA: Synchronization ChannelsCode Allocation, R
38、ec 25.223 8.3,Code Group,Associated Codes,SYNC-DLID,SYNC-ULID,Scrambling CodeID,Basic Midamble CodeID,Group 1,0,0.7,0,0,1 2 3,1 2 3,Group 2,1,8.15,4,4,. . .,5 6 7,5 6 7,Group 32,31,248.255,124,124,125 126 127,125 126 127,In a multi-frequency cell, primary frequency and secondary frequency use thesam
39、e scrambling code and basic midamble code.,1,2,3,4,TD SCDMA: Downlink SynchronizationCell Search,Search for DwPTSScrambling and Midamble Code IdentificationControl Multi-frame SyncRead the BCH, 32 SYNC_DL codes SYNC_DL code - 4 Basic Midamble Code Scrambling code Basic Midamble Code Phase Sequences
40、of DwPTSs,TD SCDMA: Uplink Synchronization,Based on DL synchronization Establish UL synchronizationRandom AccessTwo-step approach,UpPTS,UL Traffic Slots,SYNC_ULFPACHPRACH Maintain UL synchronizationMidambleSS,SS,MidambleSYNC-ULssUL burst of UE,TD SCDMA: Multiplexing Channels,Control Plane,User Plane
41、,BCCH,PCCH,DCCH,CCCH,CTCH,DTCH,Logical Channels,MAC layer,BCH,PCH,RACH,FACH,DCH,Transport Channels,PHY layer,P-CCPCH,S-CCPCH,PRACH,DPCH,Physical Channels,TD SCDMA: Multiplexing Channels,TFCI1 + TFCI2 + TFCI3 + TFCI4,1CCTrCH,1 full frame (2 sub-frames)Transport Channel 1 Physical Channel 1Transport C
42、hannel 2CCTrCH,Physical Channel 2,TD-SCMDA 1 UE may have up to4 CCTrCHs,Transport Channel 3,Energy,TD SCDMA: Joint Detection,Mobile radio propagation is affected:,multiple reflections diffractions,attenuations,Each CDMA signal is overlaid with all others in the same radio carrier and the,received (w
43、ide-band) signal can be below the thermal noise.,Spread Signals,Received Signal = -Energy of,Spread Signals,Frequency,A correlation receiver (Matched Filter Correlator) is used in order to,despread and recover the original user signal,Energy,TD SCDMA: Joint DetectionCDMA systems the received spreadi
44、ng codes are not completely orthogonalMultiple Access Interference (MAI): generated in the receiver: the desired signal does not significantly distinguish itself from interfering users whose effect can be modeled as increased background noise,Spread Signals,Detected Signal,S = correlation gainMAIFre
45、quency,Energy,TD SCDMA: Joint DetectionJoint Detection: Extracts all CDMA channels in parallel and removes the interference caused by the undesired CDMA channels (MAI). The result is a clear signal (high signal to noise ratio) for each CDMA code:Detected SignalMAI-eliminatedAdmissible,Signal,S Eb/N0
46、,FluctuationFrequencyTD-SCDMA technology allows an efficient implementation of Joint Detection receivers in the base station as well as in the terminal,TD SCDMA: Baton HandoverUtilize TDD features and uplink synchronization UE hand over with pre UL sync and stepped switch for UL/DL Support both intr
47、a- and inter frequency handovers No data loss both uplink and downlink Shorter switch gap and higher reliability compared with hard handover Lower cost compared with soft handover,CELL1,RNC,CELL0,TD SCDMA: N-Frequency CellCCSA and 3GPP R7 Multi-frequency cell Neighbor List of Cells become complex Measurements need more carefully consideration,DwPTS,GP,UpPTS,Master carrierAuxiliary carrierAuxiliary carrier,TS0,TS1TS1TS1,TS2TS2TS2,TS3TS3TS3,TS4TS4TS4,TS5TS5TS5,TS6TS6TS6,
