移动通信与仿真5-hsdpa.ppt

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1、HSDPA-FDD,吴伟民电子与信息工程系,HSDPA-FDD,Overview,Protocol Stack,MAC Layer Evolution,Transport Channel,Physical Channels,Evolution:HSDPA+,Terminal Capability Classes,Timing Structures,HSDPA-Overview,+HSDPA stands for High Speed Downlink Packet Data,+Release 5 feature of 3GPP/UTRAN,+a major upgrade to 3G syst

2、em capabilities,+HSDPA shortens round-trip time between network and terminals,+HSDPA reduces variance in downlink transmission delay,+HSDPA does not improve uplink data rates(see e-DCH called HSUPA),+HSDPA uses DCH transport channel,HSDPA-Overview,+Optimized for high-speed downlink data only SF=16 c

3、odes used,+Shorter frames(2ms including 3 Timeslots)enables faster reactions to changing channel conditions(AMC)enables faster retransmission protocol(HARQ),+Adaptative Modulation and Coding(AMC)adapts the followingtransmission format attributes modulation scheme(QPSK,16QAM)number of physical channe

4、l redundancy version error correction rate,+The UE measures the channel conditions,and indicates to Node-Bthe highest data rate(AMC)it could support through CQI indication,HSDPA-Overview,+Fast scheduling performed by the Node B,+The HARQ protocol implements a fast acknowledged data transmission sche

5、me retransmissions including the original information bits,but the data packet contains more redundancy Stop-And-Wait ARQ scheme is used in HSDPA N HARQ Processes,each Stop-And-Wait ARQ,UE 2,UE 3,UE 1,HSDPA-Overview,Multiplexing Spreading Code for one UE imposed by capability class Users are mulitpl

6、exed both in time,TTI=2ms,Codes,Time,HS-DSCH-related Shared Control Channel(HS-SCCH),HS-DSCH,High Speed Physical Downlink Shared Channel(HS-PDSCH),Dedicated Physical Control Channel(uplink)for HS-DSCH(HS-DPCCH),+UE Side:MAC-hs is responsible for HARQ-ACK(Hybrid Automatic Repeat Request)Re-ordering,+

7、NodeB Side:MAC-hs is responsible for Flow Control Scheduling/Priority Handling HARQ TFRI,MAC-d,MAC-hs,PHY,MAC-hs,PHY,L1,L2,HS-DSCHFP,L1,L2,HS-DSCHFP,MAC-d,UE,Node B,RNC,HSDPA Protocol Stack,Node B:Scheduler(Rec 25.321 11.6.1),Schedules all UEs within a cell Services priority queues:The scheduler sch

8、edules MAC-hs SDUs based on information from upper layers.One UE may be associated with one or more MAC-d flows.Each MAC-d flow contains HS-DSCH MAC-d PDUs for one or more priority queues Determines the HARQ Entity and the queue to be served Sets the TSN for new data blocks being transferred from th

9、e selected queue:Set the TSN to value 0 for the first MAC-hs PDU transmitted for each Queue ID within an HS-DSCHIncrement the TSN within one for each transmitted MAC-hs PDU on each Queue ID within an HS-DSCH Schedule new transmissions and retransmission(based on the status reportsfrom HARQ Processes

10、)Determines the redundancy version(for each transmitted and retransmittedMAC-hs PDU),HSDPA Protocol Stack,Node B:HARQ Entity(Rec 25.321 11.6.2),There is one HARQ entity for each Ue The HARQ entity sets the Queue ID in transmitted MAC-hs PDU to valueindicated by scheduler The HARQ entity sets the tra

11、nsmission sequence number(TSN)in transmitted MAC-hs PDU to value indicated by scheduler,Node B:HARQ Process(Rec 25.321 11.6.3),The HARQ process sets the New Data Indicator in transmitted MAC-hs PDU:to the value“0”for first MAC-hs PDU transmitted by a HARQ Process not increment for retransmission of

12、a MAC-hs PDU increment with one for each transmitted MAC-hs PDU containing new data The HARQ process processes received status message to the scheduler,HSDPA Protocol Stack,MAC-d for UEn,MAC-d for UE2,HARQ Entity,UE3,HARQ Entity,UE2,SCHEDULER,Queue ID 0TSN 3 New Data Ind,Node B Side,MAC-d for UE1,HS

13、DPA Protocol Stack,Queue ID 1TSN 3 New Data Ind,Reordering Entity,UE Side,HARQ Entity,UE1,HARQ Process(rec 25.321 11.6.2.2):If the MAC-hs PDU is received within 5 sub-frames from the reception of the previous MAC-hs PDU intended for this HARQ process MAC-hd PDU is discarded,HSDPA Protocol Stack,MAC-

14、d for UE1,HSDPA MAC Layer,UE Side MAC Architecture:Rec.25.321 4.2.3,HSDPA MAC Layer,UTRAN Side MAC Architecture:Rec.25.321 4.2.4,MAC-hs SDU,MAC-hs SDU,MAC-hs SDU,Padding,HSDPA MAC Layer,PDCP:TCP/IP Compressed,AMR Block Voice,MAC-hs Header,MAC-d PDU Size=336 bits,MAC-d PDU Size=336 bits,MAC-d PDU Siz

15、e=144 bits,!MAC-hs PDU!,UE1 Data,MAC-hs Payload,HSDPA MAC Layer,VF,Queue ID,TSN,SID1,N1,F1,SID2,N2,F2,VF(1 bit):Version Flag:extension capabilities 0 Normal 1 reserved Queue ID(3 bits):indication for reordering queue in the receiver,set by HARQ Entity TSN(6 bits):Transmission Sequence Number:used fo

16、r reordering purposesto support in-sequence delivery higher layers.Number of Sequenceby Queue ID SID(3 bits):Size Index Identifier,index corresponding to MAC-d size of a set ofconsecutive MAC-d PDUsSee in 25.331 10.3.5.1a MAC-d PDU size Info N(7 bits):Size Number of consecutive MAC-d PDUs with same

17、Index SetMax number PDUs per TTI in FDD 70 F(1 bit):Flag indicating if more fields are present in the MAC-hs Header,SIDk,Nk,Fk,HSDPA Transport Channel,HS-DSCH:High-Speed Downlink Shared Channel:Rec.25.212 4.5,Slot 0,Slot 1,Slot 2,2ms,One transport block once every TTI(2ms),associated with one DCH,MA

18、C-hs PDU=1 block HS-DSCH,HSDPA Transport Channel,The hybrid ARQ functionality matches the number of bits at the output of the channel coder to the total number of bits of the HS-PDSCH set to which the HS-DSCH is mapped.The hybrid ARQ functionality is controlled by the redundancy version(RV)parameter

19、s.The exact set of bits at the output of the hybrid ARQ functionality depends on the number of input bits,the number of output bits,and the RV parameters.The hybrid ARQ functionality consists of two rate-matching stages and a virtual buffer.,HS-DSCH hybrid ARQ functionality,HSDPA Physical Channel,HS

20、-PDSCH:High Speed-Physical Downlink Shared Channel,TTI=2ms,Codes,Time,ONLY ONE block HS-DSCH,HS-PDSCHs,k=4M=2 for QPSK 320 bits/slotM=4 for 16QAM 640 bits/slot,slot#0,slot#1,slot#2,Size of Transport Block:TFRI,HSDPA Physical Channel,HS-SCCH:High Speed Shared Control Channel,The HS-SCCH is a fixed ra

21、te(60 kbps,SF=128)downlink physical channel used to carry downlink signalling related to HS-DSCH transmission,HSDPA Physical Channel,Coding for HS-SCCH,Rec.25.212 4.6,HS-SCCH Part 1,HS-SCCH Part 2,Slot are aligned time with the CPICH Rate 1/3 convolution coding QPSK modulation Up to 4 HS-SCCHs per U

22、E(see 25.214 6A.1.1),Slot#1,Slot#2,HS-SCCH:7680 chips,Slot#0,HSDPA Physical Channel,Coding for HS-SCCH,Rec.25.212 4.6,UE identity(16 bits):xue,1,xue,2,xue,16UE identity is the HS-DSCH Radio Network Identifier(H-RNTI sets in Radio Bearer Setup message,see 25.331 8.6.3.1b)Channelization-code-set infor

23、mation(7 bits):xccs,1,xccs,2,xccs,7P(multi-)codes starting at code O xccs,1,xccs,2,xccs,3=min(P-1,15-P)xccs,4,xccs,5,xccs,6,xccs,7=|O-1-P/8*15|,HS-PDSCHs,slot#0,slot#1,slot#2,Modulation scheme information(1 bit):xms,1,HSDPA Physical Channel,Redundancy and constellation version(3 bits):xrv,1,xrv,2,xr

24、v,3Parameters of the second rate matching stage in HARQ functionality(see Rec 25.212 4.5.4.3)New data indicator(1 bit):xnd,1 Hybrid-ARQ process information(3 bits):xhap,1,xhap,2,xhap,3 Number of Processes Memory size Process Memory size:Maximum number of soft channelbits available in the virtual IR

25、buffer Transport-block size information(6 bits):xtbs,1,xtbs,2,xtbs,6Let kt be the sum of the two values:kt=ki+k0,i.The transport block size L(kt)can be obtained by accessing the position kt.,Coding for HS-SCCH,Rec.25.212 4.6,HSDPA Physical Channel,Coding for HS-SCCH,Rec.25.321 Annex A,HSDPA Physical

26、 Channel,Code Allocation,Rec 25.213 4.3.1.2.2,HSDPA Physical Channel,HS-DPCCH10 bits/slot,HSPDA Physical Channel,HS-DPCCH,Channel Coding of HARQ-ACKRec.25.212 4.7.1,Stop-And-Wait(SAW)ARQ scheme,Node B,UE 1,HS-DSCH 1,HS-DSCH 2,ACK,NACK,HS-DSCH 2,HSDPA Physical Channel,HS-DPCCH:Channel Coding of CQI R

27、ec.25.212 4.7.1,The code words of the(20,5)code are a linear combination of the 5 basis sequences denoted Mi,n,Channel Coding,PhCH,b,0,b,1,.b,19,Physical channel mapping,CQI,a,0,a,1,.a,4,where i=0,19.,HSDPA Terminal Capability Classes,FDD HS-DSCH physical layer categories Rec 25.306 Table 5.1a,3.64

28、Mbps,13.97 Mbps,HSPDA PLUS-Evolution,MIMO Operation 64QAM Modulation New Classes up to 28 Throughput up to 21 Mbps New Downlink physical channel Fractional Dedicated Physical Channel:F-DPCH transmits TPC information for Uplink DPCCH associated Secondary serving HS-DSCH cell HSDPA in CELL FACH Mac-ehs,HSPDA Recommendations,25211-Phys Channels FDD 25212-Multiplexing and Channel Coding FDD 25213-Spreading and Modulations FDD 25306-UE Radio Access capabilities 25321 MAC25322 RLC25323 PDCP 25331-RRC,