上下行鏈路壓縮模式介紹.ppt

,壓 縮 模 式 介 紹,壓縮模式的應(yīng)用,壓縮模式(Compressed Mode) 可用于頻間硬切換、模式間切換和系統(tǒng)間切換的測量。 TGMP: Transmission Gap pattern sequence Measurement Purpose: This parameter defines the purpose this transmission gap pattern sequence is intended for. The following values are used: - for TDD measurements, one compressed mode pattern sequence can be configured with purpose TDD measurement. for FDD measurements, one compressed mode pattern sequence can be configured with purpose FDD measurement. for GSM measurements, three simultaneous compressed mode pattern sequences can be configured with purposes GSM carrier RSSI measurement, Initial BSIC identification and BSIC re-confirmation.,壓縮模式的應(yīng)用,需要UE進(jìn)行測量時，為使UE能夠執(zhí)行測量工作，UTRAN會命令UE進(jìn)入壓縮模式，同時告訴UE具體的壓縮模式參數(shù)。而UE響應(yīng)收到的“高層命令”（Higher Layers Commands）， 進(jìn)入壓縮模式進(jìn)行測量。 單接收機(jī)的UE必須同時支持上、下行壓縮模式；而雙接收機(jī)的UE，在其中一個用于測量接收，而另一個用于UTRA FDD接收時，可以不必支持下行壓縮模式，但仍然必須支持上行壓縮模式。一般情況下，可以認(rèn)為上下行壓縮模式，UE都必須支持。,壓縮模式配置流程,壓縮幀GAP位置,壓縮幀GAP的長度不能大于7.5 slot，GAP的位置有下面兩種情況：,壓縮模式的參數(shù),壓縮圖案,壓縮模式的參數(shù),TGPSI: Transmission Gap Pattern Sequence Identifier selects the compressed mode pattern sequence for which the parameters are to be set. The range of TGPSI is 1 to 6 . TGSN (Transmission Gap Starting Slot Number): A transmission gap pattern begins in a radio frame, henceforward called first radio frame of the transmission gap pattern, containing at least one transmission gap slot. TGSN is the slot number of the first transmission gap slot within the first radio frame of the transmission gap pattern; (TGSN = 0,1,14, slot) TGL1 (Transmission Gap Length 1): This is the duration of the first transmission gap within the transmission gap pattern, expressed in number of slots; (TGL = 3, 4, 5, 7, 10, 14, slot) TGL2 (Transmission Gap Length 2): This is the duration of the second transmission gap within the transmission gap pattern, expressed in number of slots. If this parameter is not explicitly set by higher layers, then TGL2 = TGL1;,壓縮模式的參數(shù),TGD (Transmission Gap start Distance): This is the duration between the starting slots of two consecutive transmission gaps within a transmission gap pattern, expressed in number of slots. If this parameter is not set by higher layers, then there is only one transmission gap in the transmission gap pattern; (TGD = 0, 15 269, slot) TGPL1 (Transmission Gap Pattern Length): This is the duration of transmission gap pattern 1, expressed in number of frames; (TGPL = 1144, ,frame) TGPL2 (Transmission Gap Pattern Length): This is the duration of transmission gap pattern 2, expressed in number of frames. If this parameter is not explicitly set by higher layers, then TGPL2 = TGPL1.,壓縮模式的參數(shù),UL/DL compressed mode selection: This parameter specifies whether compressed mode is used in UL only, DL only or both UL and DL; UL compressed mode method: The methods for generating the uplink compressed mode gap are spreading factor division by two or higher layer scheduling;(0,1) DL compressed mode method: The methods for generating the downlink compressed mode gap are puncturing, spreading factor division by two or higher layer scheduling;(0,1,2) downlink frame type: This parameter defines if frame structure type A or B shall be used in downlink compressed mode; (0,1) scrambling code change: This parameter indicates whether the alternative scrambling code is used for compressed mode method SF/2.(0,1),壓縮模式的參數(shù),TGPRC (Transmission Gap Pattern Repetition Count): This is the number of transmission gap patterns within the transmission gap pattern sequence; (TGPRC = 0,1,511) TGCFN (Transmission Gap Connection Frame Number): This is the CFN of the first radio frame of the first pattern 1 within the transmission gap pattern sequence. (TGCFN = 0,1,255) RPP : Recovery Period Power control mode specifies the uplink power control algorithm applied during recovery period after each transmission gap in compressed mode. RPP can take 2 values (mode 0 or mode 1); ITP: Initial Transmit Power mode selects the uplink power control method to calculate the initial transmit power after the gap. ITP can take two values (mode 0 or mode 1).,壓縮模式幀結(jié)構(gòu),上行鏈路,壓縮模式幀結(jié)構(gòu),下行鏈路,壓縮模式的方法,上行鏈路提供了“SF/2”,“Higher Layer Scheduling” 兩種壓縮方法。 下行鏈路提供了“Punturing”, “SF/2”,Higher Layer Scheduling”三種壓縮模式，其中的”Punturing”是有損壓縮，”SF/2”和”Higher Layer Scheduling”是無損壓縮。(固定位置打孔),壓縮模式的方法,對于非實(shí)時分組業(yè)務(wù)，可以采用”Higer Layer Scheduling”壓縮模式，優(yōu)點(diǎn)是既能夠空出所需的Transmission Gap，又不會引起系統(tǒng)負(fù)荷的瞬時額外增加。對于那些時延要求較高且數(shù)據(jù)速率不可控的業(yè)務(wù)而言，盡量用”SF/2”的壓縮模式，優(yōu)點(diǎn)是既能夠空出所需的Transmission Gap，又可保證數(shù)據(jù)的速率，缺點(diǎn)是會有瞬時的功率增加，影響系統(tǒng)的容量和穩(wěn)定性?！盤unturing”壓縮模式可以用于以下的情況a. 采用TURBO編碼的非實(shí)時分組業(yè)務(wù)；b.高系統(tǒng)負(fù)荷時的實(shí)時業(yè)務(wù)；c.SF=4的實(shí)時業(yè)務(wù)?！盤uncturing”壓縮模式盡量少用，其中的Transmission Gap不宜太大，應(yīng)考慮各傳輸信道的基帶編碼方式和碼率。,壓縮模式時隙格式,上行鏈路,壓縮模式時隙格式,下行鏈路 下行DPDCH的時隙格式壓縮模式時也分成A,B兩種類型。壓縮方法為SF/2時，時隙格式為B；壓縮模式方法為高層調(diào)度和打孔方式時，時隙格式為A。 SF=512時，只有包含TFCI比特的時隙格式支持SF/2的壓縮模式 。 SF = 4時，不支持SF/2的壓縮方式。,壓縮模式時隙格式,壓縮幀TFCI填寫,上行鏈路 壓縮幀時隙格式改變，每個slot包含的TFCI比特數(shù)增加，這樣一幀中可填TFCI比特的位置可能會超過32，所以有部分TFCI比特會被重復(fù)填寫。 重復(fù)填寫的規(guī)則是壓縮GAP之后的TFCI比特按逆序填寫到超過32bit的TFCI位置上。,壓縮幀TFCI填寫,下行鏈路 壓縮幀非壓縮時隙的TFCI域比特數(shù)大于正常時隙格式對應(yīng)的TFCI比特數(shù)時，多余部分插入DTX。時隙格式011時，TFCI發(fā)送F = 32bits；時隙格式1216時，TFCI發(fā)送F = 128bits。 設(shè)E = Nfirst * Ntfci，有三種插入DTX的情況：,壓縮幀DATA填寫,下行鏈路SF/2方式，壓縮幀數(shù)據(jù)域只發(fā)送7.5slots，控制域仍按TGL填寫。 If Nfirst + TGL 15, i.e. the transmission gap spans one radio frame, if Nfirst + 7 14 no bits are mapped to slots Nfirst,Nfirst + 1, Nfirst +2, Nfirst+6 no bits are mapped to the first (NData1+ NData2)/2 bit positions of slot Nfirst+7 if Nfirst + 7 14 no bits are mapped to slots Nfirst, Nfirst + 1, Nfirst + 2, 14 no bits are mapped to slots Nfirst - 1, Nfirst - 2, Nfirst - 3, , 8 no bits are mapped to the last (NData1+ NData2)/2 bit positions of slot 7 If Nfirst + TGL 15, i.e. the transmission gap spans two consecutive radio frames, In the first radio frame, no bits are mapped to last (NData1+ NData2)/2 bit positions in slot 7 as well as to slots 8, 9, 10, ., 14. In the second radio frame, no bits are mapped to slots 0, 1, 2, ., 6 as well as to first (NData1+ NData2)/2 bit positions in slot 7.,壓縮模式碼信息,上行鏈路 擴(kuò)頻碼 Cch,SF,k ,Cch,SF_cm,k_cm SF/2方式：SF_cm = SF/2,k_cm = SF_cm/4; 高層調(diào)度方式：SF_cm = SF,k_cm = k。 擾碼 擾碼跟正常模式相同。,壓縮模式碼信息,下行鏈路 擴(kuò)頻碼Cch,SF,k ,Cch,SF_cm,k_cm SF/2方式：SF_cm = SF/2,k_cm = , k/2 （不用替換擾碼）， k_cm = k mod SF/2（使用替換擾碼）。 高層調(diào)度和打孔方式：SF_cm = SF,k_cm = k。 擾碼 SF/2方式：如果不使用替換擾碼，跟正常模式相同；如果使用替 換擾碼，k=SF/2，用右替換 擾碼。是否使用替換擾碼由高層通知。 高層調(diào)度和打孔方式：跟正常模式相同。,壓縮模式的功控,上行鏈路 壓縮模式功控的目的是為了盡快恢復(fù)GAP之后的SIR到SIRtarget。NodeB根據(jù)SIR與SIRtarget的大小產(chǎn)生TPC Cpmmand，壓縮模式時用下面的公式計算SIRtarget： SIRcm_target = SIRtarget + SIRPILOT + SIR1_coding + SIR2_coding ; SIRPILOT = 10Log10 (Npilot,N/Npilot,curr_frame); Npilot,curr_frame ：當(dāng)前壓縮幀每個slot的導(dǎo)頻比特數(shù)。 Npilot,N: ：正常幀每個slot的導(dǎo)頻比特數(shù)。,壓縮模式的功控,下行鏈路 下行每個非GAP的slot，UTRAN 估計第k個TPC 命令并且按照下面的公式調(diào)整當(dāng)前下行發(fā)送功率 P(k-1) dB到一個新的值 P(k) dB： P(k) = P(k - 1) + PTPC(k) + PSIR(k) + Pbal(k); PTPC(k)：上行無TPC_cmd時，對應(yīng)PTPC(k) = 0 ，否則按照正常模式計算， 只是在GAP之后的RPLslots用DSTEP 代替 DTPC。 RPL： RPL is equal to the minimum value out of the transmission gap length and 7 slots. RPL = Min(TGL,7)。如果有新的GAP出現(xiàn)在RPL的結(jié) 束之前，那么RPL就停止于新的