移动通信与仿真4-TD_SCDMA.ppt

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 Path 3GPP,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 Frequency Cell,TD-SCDMA Stage II （R5） Multi-carrier,Standardization,2006,Short Term Evolution 2008,Long Ter

3、m Evolution,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,Code C3 C2,Frequency,User 3 User 2 User 1,C1,CDMA,Time,1 user W-CDMA,1 Code,Spreading Factor Max,512 Codes,TD-SCDMA,Spre

4、ading Factor Max,16 Codes,TD SCDMA Vs W-CDMA,code,time,User 1,User 2,W-CDMA,UL,DL,frequency,5 MHz,190 MHz code,time 16code,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 tr

5、affic and services, 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

6、 speed/mobility users Complex and expensive technologies,7,TD SCDMA System Parameters,Parameter Carrier bandwidth Carrier spacing Chip rate Duplex type Multiple access scheme Frame length Number of slots/sub-frames Radio frame length Radio-subframe length Data modulation Voice data rate Receiver Spr

7、eading factors Max data rate per user (theoretical) Synchronization Antenna processing,Value 1.6 MHz 1.6 MHz 1.28 Mcps TDD TDMA, CDMA, FDMA 10 ms 10 ms 5 ms QPSK or 8-PSK 8 Kbit/s Joint detector (rake in UE) 1, 2, 4, 8 and 16 2 Mbps Downlink and uplink Smart antenna with beam forming,TD SCDMA: Frame

8、 Structure Chip rate: 1.28 Mcps,10ms Radio frame #i 5ms,Radio frame #i+1 5ms,Bandwidth: 1.6 MHz Modulation: QPSK/8PSK/16QAM Duplex: TDD DwPTS : 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 chips

9、 Data 1,144 chips Midamble,352 chips Data 2,GP3,16 chips,First Switch Point: GP1 (96 chips), Second Switch Point: after TS1,DL,UL,UL/DL,GP,GP,16,CP,-,-,TD SCDMA: Physical Channel DPCH: Dedicated Physical Channel, Rec 25.221 5A.2 Burst structure of the traffic burst format,Data symbols 352 chips,Mida

10、mble 144 chips,Data symbols 352 chips,864*Tc 16 SF= 16 code channel per timeslot per Carrier,Spreading factor (Q) 1 2 4 8 16,Number of symbols (N) per data field in Burst 352 176 88 44 22,The contents of the traffic burst format fields,Chip number (CN) 0-351 352-495 496-847 848-863,Length of field i

11、n chips 352 144 352 16,Length of field in symbols cf table 8A cf table 8A,Contents of field Data symbols Midamble Data symbols Guard period,1,st,2,3,P,P,3,1,st,rd,P,P,TD SCDMA: Physical Channel DPCH: Transmission of TFCI, Rec 25.221 5A.2.2.1 Position of the TFCI code word in the traffic burst in cas

12、e of no TPC and SS,part of,TFCI code word,nd,part of,TFCI code word,rd,part of,TFCI 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 10ms Position of

13、 the TFCI code word in the traffic burst in case of TPC and SS,part of TFCI code word,SS,TPC symbols,symbols 2 nd part of TFCI code word,part of TFCI code word SS symbols,TPC,symbols 4 th part of TFCI code word,G,G,Data symbols,Midamble,Data symbols,Data symbols,Midamble,Data symbols,Time slot x (86

14、4 Chips),Time slot x,(864 Chips),Sub-frame 5ms,Radio Frame 10ms,Sub-frame 5ms,GP,0,1,TD SCDMA: Physical Channel DPCH: Transmission of TPC / SS, Rec 25.221 5A.2.2.2 Position of TPC information in the traffic burst in downlink and uplink,SS symbol(s),TPC symbol(s),Data symbols,Midamble,Data symbols,14

15、4 chips 864 Chips Coding of the SS for QPSK,TPC Bit Pattern for BPSK,SS Bits,SS command,Meaning,bTPC,TPC,Meaning,00,Down,Decrease synchronisation shift by k/8,command,Tc,Down Up,Decrease Tx Power Increase Tx Power,11 01,Up Do nothing,Increase synchronisation shift by k/8 Tc No change,TPC Bit Pattern

16、 for 8PSK,Coding of the SS for 8PSK,TPC Bits 000 110,TPC command Down Up,Meaning Decrease Tx Power Increase Tx Power,SS Bits 000,SS command Down,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 t

17、iming adjustment by (k/8) Tc each M sub-frames, where Tc is the chip period. The k and M values are signalled by the network.,field(1),TD SCDMA: Physical Channel,DPCH: Timeslot Formats Rec 25.221 5A.2.4.1 Time slot formats for the Downlink QPSK Time slot formats for the Uplink,Slot Format # 0 1 2 22

18、 23 24 Slot Format # 0 1 2 10 25 40 69,Spreading Factor 16 16 16 1 1 1 Spreading Factor 16 16 16 8 4 2 1,Midamble length (chips) 144 144 144 144 144 144 Midamble length (chips) 144 144 144 144 144 144 144,NTFCI code word (bits) 0 4 8 8 16 32 NTFCI code word (bits) 0 4 8 0 0 0 32,NSS ; bit sequence (

19、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-frame difference Received starting position of the UpPCH: range 0 8191 Transmit power level command is transmitted in 7 bits,Data symb

20、ols 352 chips,Midamble 144 chips 864*Tc,Data symbols 352 chips,The FPACH uses slot format #0, SF=16,TD SCDMA: Physical Channels Synchronisation Channels, Rec 25.221 5A.3.5,DwPTS(75us),GP1(75us),UpPTS (125us),GP2,SYN C_DL,SYNC_UL,GP2,TS0,(32chips),(64chips),(128chips),(32chips),TS1,DwPCH: Downlink Pi

21、lot Channel 32 SYNC_DL avalaible codes 1 cell SYNC_DL code,UpPCH: Uplink Pilot Channel 256 SYNC_UL codes 32 Groups, 8 codes per group,In a multi-frequency cell the DwPCH shall be transmitted only on the primary frequency. The UpPCH is transmitted on the primary frequency. The UpPCH may also be trans

22、mitted on the secondary frequencies in case of handover.,( ),codes,S1,S2,0,1,2,3,TD SCDMA: Synchronization Channels Downlink Pilot CHannel, Rec 25.223 8.1 For the generation of the complex valued SYNC-DL codes of length 64, the basic binary SYNC-DL s = S 1, s 2 ,. , s 64 SYNC-DL is QPSK modulated an

23、d the phase of the SYNC-DL is used to signal the presence of the P-CCPCH . The SYNC-DL code is not scrambled. Four consecutive phases (phase quadruple) of the SYNC-DL are used to indicate the presence of the P-CCPCH in the following 4 sub-frames Sequences for the phase modulation for the SYNC-DL,Nam

24、e,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,Code ID,SYNC-DL Codes of,length 64 B3A7CC05A98688E4 9D559BD290606791 2CE7BA12A017C3A2 34511D20672F4712,. 28 29 30

25、31,. D4354B2FE02361CC 5383AB6C8A10CE84 D417A730F2F12244 ABF0A0D905A939C4,s,0,1,2,3,4,5,6,251,252,253,254,255,TD SCDMA: Synchronization Channels Uplink Pilot CHannel, Rec 25.223 8.2 UpPCH : generation of the complex valued SYNC-UL codes of length 128 s = ( 1, s 2 ,. , s128) Table AA.2: 256 Basic SYNC

26、-UL Codes,Code ID ,SYNC-UL Codes of length 128 C11C20F0D1807DB8859175B798EC094A 91278068081EC8E74543DBC1C9AD4235 38F5AEE2E513DB12A663BA04160103E5 7AA8A0A210F12A1E4332F2EDD33011FC C180EA3B9BA1774EB9611BD249C4A508 B072A2C839489D496B98CE9D0132FBC9 B2723EAC6EB01667F2B33961C8074234 . 68FC090C2221AA98BF0D

27、24E85066EFC2 9E26CEC67832FC42A87E92FA1015212E ACD889634F79506F2582EA03240F2A07 AA65407E1F4A33BF9A62860A3D6A4CC0 B1B950AC76A608AA32D04B03C7FF24D3,TD SCDMA: Synchronization Channels Code Allocation, Rec 25.223 8.3,Code Group,Associated Codes,SYNC-DL ID,SYNC-UL ID,Scrambling Code ID,Basic Midamble Code

28、 ID,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 the same scrambling code and basic midamble code.,1,2,3,4,TD SCDMA: Downlink Synchronization Cell Search

29、,Search for DwPTS Scrambling and Midamble Code Identification Control Multi-frame Sync Read the BCH, 32 SYNC_DL codes SYNC_DL code - 4 Basic Midamble Code Scrambling code Basic Midamble Code Phase Sequences of DwPTSs,TD SCDMA: Uplink Synchronization,Based on DL synchronization Establish UL synchroni

30、zation Random Access Two-step approach,UpPTS,UL Traffic Slots,SYNC_UL FPACH PRACH Maintain UL synchronization Midamble SS,SS,Midamble SYNC-UL ss UL burst of UE,TD SCDMA: Multiplexing Channels,Control Plane,User Plane,BCCH,PCCH,DCCH,CCCH,CTCH,DTCH,Logical Channels,MAC layer,BCH,PCH,RACH,FACH,DCH,Tran

31、sport 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 1 Transport Channel 2 CCTrCH,Physical Channel 2,TD-SCMDA 1 UE may have up to 4 CCTrCHs,Transpor

32、t 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 (wide-band) signal can be below the thermal noise.,Spread Signals,Received Signal

33、= -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 Detection CDMA systems the received spreading codes are not completely orthogonal Multiple 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