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1、Differential Analysis on of TD-LTE and LTE FDD,TD-LTE System, HAO Dandan,Outline,Executive Summary of Differential Analysis Key Differential Analysis Algorithm Analysis Requirements for next step Cooperation Note: This PPT is based on the version of 3GPP Rel.8 36 series released in Dec. 2008.,Execut
2、ive Summary of Differential Analysis for Physical Layer,Physical Layer Differential Analysis,Physical Layer Differential Analysis,Physical Layer Differential Analysis,Physical Layer Differential Analysis,Physical Layer Differential Analysis,MAC/RLC/PDCP/RRC/NAS,Key Differential Analysis,Outline,Fram
3、e structure Cell Search Random Access HARQ Special Subframe Frequency Band,Key Differential Analysis Frame Structure,Frame structure Frame structure type 1 - FDD Frame structure type 2 TDD TD-LTE frame structure can flexible configured, and can align with TD-SCDMA system. So the TD-SCDMA and TD-LTE
4、can co-exist at same position.,Key Differential Analysis Frame Structure,High impact on Phy software: 7 Frame structures X 9 special subframes = 63 Frame configurations for TD-LTE vs. 1 for FDD (normal cyclic prefix) Control of special subframes Switching from DL to UL (min. GP given by TA) Differen
5、t rate matching Control of subframes DL or UL only Switching from UL to DL within a gap of minimum timing advance TAoffs = 20 ms Guard Period (GP) between DL and UL Standard timing advance (TA) mechanism used,8DL+DwPTS:1UL,TA+TAoffs,GP,Frame structures,Key Differential Analysis Cell Search,Cell Sear
6、ch The position of P-SCH and S-SCH is different for FDD and TDD,The AGC and AFC control and adjustment procedure should be different for FDD and TDD,Key Differential Analysis - PRACH,Random Access Preamble format 4 is for frame structure type 2 only, UpPTS can be used to sending preamble. Preamble m
7、apping in time and frequency is different for frame structure type 1 and type 2 For frame structure type 2, there might be multiple random access resources in an UL subframe.,Release buffer,Release buffer,Discard,Key Differential Analysis - HARQ,8 HARQ buffers and 8 processes for FDD, up to 15 proce
8、sses specified for TD-LTE (config 5) Implementation of TD-LTE specific ACK/NACK timing UL HARQ Varying number of PHICH groups in a frame (config 0) Extension of DCI formats on PDCCH Implementation of TD-LTE bit-fields in DCI formats,4,5,6,7,8,9,10,11,12,13,14,15,1,2,3,Process #:,5,Keep buffer,Take n
9、ext buffer,3,Take next buffer,5,Keep buffer,Take next buffer,9,Take next buffer,14,11,2,1,3,2,4,5,6,7,8,6,2,7,8,10,12,15,NACK,ACK,#,HARQ Buffer occupied by process #,No buffer,3,-,-,2xPHICH,1xPHICH,Frame configuration 0,Key Differential Analysis - HARQ,According to 3GPP TS 36.213: The number of HARQ
10、 processes is determined by the DL/UL configuration. Upon detection of a PDCCH with DCI format 0 and/or a PHICH transmission in subframe n intended for the UE, the UE shall: Adjust the corresponding PUSCH transmission in subframe n+k, with k3 according to the PDCCH and PHICH information Transmit the
11、 ACK/NACK response in UL subframe n+k, with k3, (if ACK/NACK is provided) The use of a single ACK/NACK response for providing HARQ feedback for multiple PDSCH transmissions is supported by performing logical AND of all the corresponding individual PDSCH transmission ACK/NACKs.,n+k, k=8,n+k, k=7,n+k,
12、 k=6,n+k, k=4,bundling,Key Differential Analysis ACK/NACK,ACK/NACKs of multiple DL subframes in one UL subframe Bundling (AND of ACKs) for PUCCH/PUSCH Multiple ACK/NACKs combined to single ACK/NACK Reuse of existing PUCCH formats Multiplexing (multiple ACKs) for PUCCH/PUSCH Multiple ACK/NACKs combin
13、ed over MIMO code words Reuse of existing PUCCH formats by using multiple PUCCH resources Handle missed DL assignments (DAI) Combinations with CQI, SR, SRS Def: PUCCH = Physical UL control channel Def: PUSCH = Physical UL shared channel,Key Differential AnalysisACK/NACK encoding and timing,UL ACK/NA
14、CK for DL HARQ Bundling and multiplexing for PUCCH Determination and selection of PUCCH resource index,n+k, k=8,n+k, k=7,n+k, k=6,n+k, k=4,bundling,Key Differential Analysis Special Subframe,Normal CP 14 symbols/subframe,Extended CP 12 symbols/subframe,3:10:1,3:8:1,9:4:1,10:3:1,11:2:1,12:1:1,3:9:2,9
15、:3:2,10:2:2,11:1:2,8:3:1,9:2:1,10:1:1,3:7:2,8:2:2,9:1:2,DwPTS,UpPTS,Key Differential Analysis Special Subframe,DwPTS/UpPTS DwPTS PCFICH、PDCCH、PHICH、PDSCH and P-SCH P-SCH is located at third symbol of DwPTS At last two symbol for downlink control UpPTS Sounding RS PRACH,Key Differential Analysis UE s
16、pecific reference signals,Extraction and control of dedicated pilots Channel estimation for discontinuous DL Fast channel estimator settling (kick start function) New time domain filtering parameters for UL to DL switch points New frequency domain filtering parameters,Frequency Band Characteristics FDD,Frequency Band Characteristics TDD,THANK YOU,