移动通信与仿真4-TD_SCDMA

nullnull吴伟民 电子与信息工程系 wuwm@hust.edu.cn*nullTD-SCDMAEvolution PathTD-SCDMA: Frequency BandTD-SCDMA Vs W-CDMASystem ParamtersFrame StructurePhysical ChannelsSynchronization Channels Downlink Synchronization Uplink Synchronization Multiplexing Channels Joint Detection Baton Handover N-Frequency Cellnull TD-SCDMA Evolution Path 3GPPLCR TDD （R4）LCR TDD （R5）LCR TDD (R6)LCR TDD (R7)LTE TDD CCSA China Communications StandardsTD-SCDMA Stage III （R7）OFDM/SC-FDMAAssociationTD-SCDMA Stage I （R4 2003/03） N Frequency CellTD-SCDMA Stage II （R5） Multi-carrierStandardization2006Short Term Evolution 2008Long Term EvolutionnullTD-SCDMA: Frequency Band1755 17851850 188019201980 2010 202521102170 23002400SatelliteSatellite 30 MHz60 MHz 40 MHz 15 MHz100 MHzFDDTDDnullTD-SCDMA Vs W-CDMACode C3 C2FrequencyUser 3 User 2 User 1C1CDMATime 1 user W-CDMA1 CodeSpreading Factor Max512 CodesTD-SCDMASpreading Factor Max16 CodesnullTD SCDMA Vs W-CDMAcodetimeUser 1User 2W-CDMAULDLfrequency5 MHz190 MHz code time 16codeTD-SCDMAfrequencycan be usednullTD SCDMA Vs W-CDMA3 simultaneous technologiesnullTD SCDMA Vs W-CDMAAvantages of TD-SCDMA:☺ Efficient spectrum allocation☺ Support for asymmetric traffic 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 endDisdavantages of TD-SCDMA:▼ Requires accurate synchronization▼Limited support for high speed/mobility users ▼ Complex and expensive technologiesnull7TD 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 Spreading 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 formingnullTD SCDMA: Frame 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 #2U ppt 关于艾滋病ppt课件精益管理ppt下载地图下载ppt可编辑假如ppt教学课件下载triz基础知识ppt S : Uplink Pilot TimeSlot (160 chips)DwPTS GP1UpPTSTS0TS1TS2TS3TS4TS5TS6352 chips Data 1 144 chips Midamble352 chips Data 2GP316 chipsFirst Switch Point: GP1 (96 chips), Second Switch Point: after TS1DLULUL/DLGPnullGP16CP-- TD SCDMA: Physical Channel DPCH: Dedicated Physical Channel, Rec 25.221 § 5A.2 Burst structure of the traffic burst formatData symbols 352 chipsMidamble 144 chipsData symbols 352 chips864*Tc 16 SF= 16 code channel per timeslot per CarrierSpreading factor (Q) 1 2 4 8 16Number of symbols (N) per data field in Burst 352 176 88 44 22The contents of the traffic burst format fieldsChip number (CN) 0-351 352-495 496-847 848-863Length of field in chips 352 144 352 16Length of field in symbols cf table 8A cf table 8A Contents of field Data symbols Midamble Data symbols Guard periodnull1st23PP31strdPP 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 case of no TPC and SSpart ofTFCI code wordndpart ofTFCI code wordrdpart ofTFCI code word4 th part ofTFCI code wordGGData symbolsMidambleData symbolsData symbolsMidambleData symbolsTime slot x (864 Chips) Sub-frame 5msTime slot x (864 Chips) Sub-frame 5ms Radio Frame 10ms Position of the TFCI code word in the traffic burst in case of TPC and SSpart of TFCI code wordSS TPC symbolssymbols 2 nd part of TFCI code wordpart of TFCI code word SS symbolsTPCsymbols 4 th part of TFCI code wordGGData symbolsMidambleData symbolsData symbolsMidambleData symbolsTime slot x (864 Chips)Time slot x(864 Chips)Sub-frame 5msRadio Frame 10msSub-frame 5msnullGP01 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 uplinkSS symbol(s)TPC symbol(s)Data symbolsMidambleData symbols144 chips 864 Chips Coding of the SS for QPSKTPC Bit Pattern for BPSKSS BitsSS commandMeaningbTPCTPCMeaning00'Down'Decrease synchronisation shift by k/8commandTc'Down' 'Up'Decrease Tx Power Increase Tx Power11 01 'Up' ‘Do nothing’Increase synchronisation shift by k/8 Tc No changeTPC Bit Pattern for 8PSKCoding of the SS for 8PSKTPC Bits 000 110TPC command 'Down' 'Up'Meaning Decrease Tx Power Increase Tx PowerSS Bits 000SS command 'Down' Meaning Decrease synchronisation shift by k/8 Tc110 011 'Up' ‘Do nothing’Increase synchronisation shift by k/8 Tc No changeThe 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 signalled by the network.nullfield(1)TD SCDMA: Physical ChannelDPCH: 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 23 24 Slot Format # 0 1 2 10 25 40 69Spreading Factor 16 16 16 1 1 1 Spreading Factor 16 16 16 8 4 2 1Midamble 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 32NSS & NTPC (bits) 0&0 0&0 0&0 32 & 32 32 & 32 32 & 32 NSS & NTPC (bits) 0&0 0&0 0&0 0&0 0&0 0&0 32 & Bits/slot 88 88 88 1408 1408 1408 Bits/slot 88 88 88 176 352 704 1408 NData/Slot (bits) 88 86 84 1340 1336 1328 NData/Slot (bits) 88 86 84 176 352 704 1328 Ndata/data (bits) 44 42 42 702 700 696 Ndata/data (bits) field(1) 44 42 42 88 176 352 696 Ndata/data field(2) (bits) 44 44 42 638 636 632 Ndata/data field(2) (bits) 44 44 42 88 176 352 63232nullt TD SCDMA: Physical Channel DPCH: Timeslot Formats Rec 25.221 § 5A.2.4.2SlotSpreadingMidambleNTFCINSS &Bits/sloNData/SlotNdata/dataNdata/data8PSKFormat #Factorlength (chips)code word (bits) NTPC (bits)(bits)field(1) (bits)field(2) (bits)0 1 21 1 1144 144 144 0 6 120&0 0&0 0&02112 2112 21122112 2109 21061056 1053 10531056 1056 1053Time slot formats for the Downlink & Uplink… 20 21 22 23 24… 16 16 16 16 16… 144 144 144 144 144… 0 6 12 24 48 … 3&3 3&3 3&3 3&3 3&3… 132 132 132 132 132… 126 123 120 114 102… 66 63 63 60 54… 60 60 57 54 48null1 2 TD SCDMA: Physical Channel P-CCPCH: Primary common control physical channel, Rec 25.221 § 5A.3.1 ‘Common Transport Channels’ is mapped onto the Primary Common Control Physical Channels (P-CCPCH1 and P-CCPCH2) The P-CCPCHs are mapped onto the first two code channels of timeslot#0 with spreading factor of 16cQk=16 cQk=16BCHData symbols 352 chipsMidamble 144 chipsData symbols 352 chipsGP 16 CP 864*Tc No TFCI is applied for the P-CCPCHnull1st2P-GP16CP TD SCDMA: Physical Channel S-CCPCH: Secondary Common Control Physical channel, Rec 25.221 § 5A.3.1 The time slot and codes used for the S-CCPCH are broadcast on the BCH In a multi--frequency cell S--CCPCH shall be transmitted only on the primary frequencypart of TFCI code wordndpart of TFCI code wordGData symbols Midamble Time slot x (864 Chips)Data symbolsTFCI is applied for the S-CCPCH Fixed SF = 16Data symbols 352 chipsMidamble 144 chipsData symbols 352 chips 864*Tc No TFCI is applied for the S-CCPCHnull TD SCDMA: Physical Channel PRACH: Physical Random Access CHannel, Rec 25.221 § 5A.3.4 The RACH is mapped onto one or more uplink physical random access channels (PRACH). In such a way the capacity of RACH can be flexibly scaled depending on the operators need.Data symbols 352 chipsMidamble 144 chipsData symbols 352 chipsGP 16 CP 864*Tc PRACH timeslot formatsSpreading Factor 16 8 4Slot Format # 0 10 25In a multi-frequency cell the PRACH shall be transmitted only on the primary frequency.null1129 (LSB)7GP16CP TD SCDMA: Physical Channel FPACH: Fast Physical Access Channel, Rec 25.221 § 5A.3.3 The 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 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 transmitted on the secondary frequency in case of handover. FPACH information 32 bits description Information 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 bits (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-frame difference Received starting position of the UpPCH: range 0 – 8191 Transmit power level command is transmitted in 7 bitsData symbols 352 chipsMidamble 144 chips 864*TcData symbols 352 chipsThe FPACH uses slot format #0, SF=16null•••• TD SCDMA: Physical Channels Synchronisation Channels, Rec 25.221 § 5A.3.5DwPTS(75us)GP1(75us)UpPTS (125us)GP2SYN C_DLSYNC_ULGP2TS0(32chips)(64chips)(128chips)(32chips)TS1DwPCH: Downlink Pilot Channel 32 SYNC_DL avalaible codes 1 cell <-> SYNC_DL codeUpPCH: 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 transmitted on the secondary frequencies in case of handover.null( )codesS1S20123 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 and 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-DLName Phase quadruple 135, 45, 225, 135 Meaning There is a P-CCPCH in the next 4 sub-framesTable AA.1: 32 Basic SYNC-DL Codes315, 225, 315, 45There is no P-CCPCH in the next 4 sub-framesCode IDSYNC-DL Codes of length 64 B3A7CC05A98688E4 9D559BD290606791 2CE7BA12A017C3A2 34511D20672F4712…. 28 29 30 31 ….. D4354B2FE02361CC 5383AB6C8A10CE84 D417A730F2F12244 ABF0A0D905A939C4nulls0123456251252253254255 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-UL CodesCode ID … SYNC-UL Codes of length 128 C11C20F0D1807DB8859175B798EC094A 91278068081EC8E74543DBC1C9AD4235 38F5AEE2E513DB12A663BA04160103E5 7AA8A0A210F12A1E4332F2EDD33011FC C180EA3B9BA1774EB9611BD249C4A508 B072A2C839489D496B98CE9D0132FBC9 B2723EAC6EB01667F2B33961C8074234 …. 68FC090C2221AA98BF0D24E85066EFC2 9E26CEC67832FC42A87E92FA1015212E ACD889634F79506F2582EA03240F2A07 AA65407E1F4A33BF9A62860A3D6A4CC0 B1B950AC76A608AA32D04B03C7FF24D3null TD SCDMA: Synchronization Channels Code Allocation, Rec 25.223 § 8.3 Code GroupAssociated CodesSYNC-DL IDSYNC-UL IDScrambling Code IDBasic Midamble Code IDGroup 100...7001 2 31 2 3Group 218...1544. . .5 6 75 6 7Group 3231248...255124124125 126 127125 126 127In a multi-frequency cell, primary frequency and secondary frequency use the same scrambling code and basic midamble code.null1234 TD SCDMA: Downlink Synchronization Cell SearchSearch 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 DwPTSsnullTD SCDMA: Uplink SynchronizationBased on DL synchronization Establish UL synchronization Random Access Two-step approachUpPTSUL Traffic Slots SYNC_UL FPACH PRACH Maintain UL synchronization Midamble SSSS Midamble SYNC-UL ss UL burst of UEnullTD SCDMA: Multiplexing ChannelsControl PlaneUser PlaneBCCHPCCHDCCHCCCHCTCHDTCH Logical ChannelsMAC layerBCHPCHRACHFACHDCHTransport ChannelsPHY layerP-CCPCHS-CCPCHPRACHDPCH Physical ChannelsnullTD SCDMA: Multiplexing ChannelsTFCI1 + TFCI2 + TFCI3 + TFCI41CCTrCH 1 full frame (2 sub-frames) Transport Channel 1 Physical Channel 1 Transport Channel 2 CCTrCHPhysical Channel 2 TD-SCMDA 1 UE may have up to 4 CCTrCHsTransport Channel 3nullEnergyTD SCDMA: Joint DetectionMobile radio propagation is affected:multiple reflections diffractionsattenuationsEach CDMA signal is overlaid with all others in the same radio carrier and thereceived (wide-band) signal can be below the thermal noise.Spread SignalsReceived Signal = Σ-Energy ofSpread SignalsFrequencyA correlation receiver (Matched Filter Correlator) is used in order todespread and recover the original user signalnullEnergy 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 noiseSpread SignalsDetected Signal S = correlation gain MAI FrequencynullEnergy TD SCDMA: Joint Detection Joint 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 Signal MAI-eliminated AdmissibleSignalS ≈ Eb/N0 Fluctuation Frequency TD-SCDMA technology allows an efficient implementation of Joint Detection receivers in the base station as well as in the terminalnull TD SCDMA: Baton Handover Utilize TDD features and uplink synchronization UE hand over with pre UL sync and stepped switch for UL/DL Support both intra- 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 handoverCELL1RNCCELL0null TD SCDMA: N-Frequency Cell CCSA and 3GPP R7 Multi-frequency cell Neighbor List of Cells become complex Measurements need more carefully considerationDwPTSGPUpPTS Master carrier Auxiliary carrier Auxiliary carrierTS0TS1 TS1 TS1TS2 TS2 TS2TS3 TS3 TS3TS4 TS4 TS4TS5 TS5 TS5TS6 TS6 TS6