上下行链路压缩模式介绍.ppt

1、,压 缩 模 式 介 绍,压缩模式的应用,压缩模式(Compressed Mode) 可用于频间硬切换、模式间切换和系统间切换的测量。 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 patter

2、n 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 measuremen

3、t, Initial BSIC identification and BSIC re-confirmation.,压缩模式的应用,需要UE进行测量时，为使UE能够执行测量工作，UTRAN会命令UE进入压缩模式，同时告诉UE具体的压缩模式参数。而UE响应收到的“高层命令”（Higher Layers Commands）， 进入压缩模式进行测量。 单接收机的UE必须同时支持上、下行压缩模式；而双接收机的UE，在其中一个用于测量接收，而另一个用于UTRA FDD接收时，可以不必支持下行压缩模式，但仍然必须支持上行压缩模式。一般情况下，可以认为上下行压缩模式，UE都必须支持。,压缩模式配置流程,压缩帧

4、GAP位置,压缩帧GAP的长度不能大于7.5 slot，GAP的位置有下面两种情况：,压缩模式的参数,压缩图案,压缩模式的参数,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 pat

5、tern 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 (Tra

6、nsmission 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, e

7、xpressed in number of slots. If this parameter is not explicitly set by higher layers, then TGL2 = TGL1;,压缩模式的参数,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

8、. 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 = 1.144, ,frame) TGPL2

9、(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.,压缩模式的参数,UL/DL compressed mode selection: This parameter specifies whether compressed mode is used in UL

10、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

11、 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

12、method SF/2.(0,1),压缩模式的参数,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

13、 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 Powe

14、r 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).,压缩模式帧结构,上行链路,压缩模式帧结构,下行链路,压缩模式的方法,上行链路提供了“SF/2”,“Higher Layer Scheduling” 两种压缩方法。 下行链路提供了“Punturing”, “SF/2”,Higher Layer Scheduling”三种压缩模式，其中的”Punturing”

15、是有损压缩，”SF/2”和”Higher Layer Scheduling”是无损压缩。(固定位置打孔),压缩模式的方法,对于非实时分组业务，可以采用”Higer Layer Scheduling”压缩模式，优点是既能够空出所需的Transmission Gap，又不会引起系统负荷的瞬时额外增加。对于那些时延要求较高且数据速率不可控的业务而言，尽量用”SF/2”的压缩模式，优点是既能够空出所需的Transmission Gap，又可保证数据的速率，缺点是会有瞬时的功率增加，影响系统的容量和稳定性。”Punturing”压缩模式可以用于以下的情况a. 采用TURBO编码的非实时分组业务；b.高系

16、统负荷时的实时业务；c.SF=4的实时业务。”Puncturing”压缩模式尽量少用，其中的Transmission Gap不宜太大，应考虑各传输信道的基带编码方式和码率。,压缩模式时隙格式,上行链路,压缩模式时隙格式,下行链路 下行DPDCH的时隙格式压缩模式时也分成A,B两种类型。压缩方法为SF/2时，时隙格式为B；压缩模式方法为高层调度和打孔方式时，时隙格式为A。 SF=512时，只有包含TFCI比特的时隙格式支持SF/2的压缩模式 。 SF = 4时，不支持SF/2的压缩方式。,压缩模式时隙格式,压缩帧TFCI填写,上行链路 压缩帧时隙格式改变，每个slot包含的TFCI比特数增加，这

17、样一帧中可填TFCI比特的位置可能会超过32，所以有部分TFCI比特会被重复填写。 重复填写的规则是压缩GAP之后的TFCI比特按逆序填写到超过32bit的TFCI位置上。,压缩帧TFCI填写,下行链路 压缩帧非压缩时隙的TFCI域比特数大于正常时隙格式对应的TFCI比特数时，多余部分插入DTX。时隙格式011时，TFCI发送F = 32bits；时隙格式1216时，TFCI发送F = 128bits。 设E = Nfirst * Ntfci，有三种插入DTX的情况：,压缩帧DATA填写,下行链路SF/2方式，压缩帧数据域只发送7.5slots，控制域仍按TGL填写。 If Nfirst +

18、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,

19、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 b

20、it 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.,压缩模式码信息,上行链路 扩频码 Cch,SF,k ,Cch,SF_cm,k_cm SF/2方式：SF_cm = SF/2,k_cm = SF_cm/4; 高层调度方式：SF_cm = SF,k_cm = k。 扰

21、码 扰码跟正常模式相同。,压缩模式码信息,下行链路 扩频码Cch,SF,k ,Cch,SF_cm,k_cm SF/2方式：SF_cm = SF/2,k_cm = , k/2 （不用替换扰码）， k_cm = k mod SF/2（使用替换扰码）。 高层调度和打孔方式：SF_cm = SF,k_cm = k。 扰码 SF/2方式：如果不使用替换扰码，跟正常模式相同；如果使用替 换扰码，k=SF/2，用右替换 扰码。是否使用替换扰码由高层通知。 高层调度和打孔方式：跟正常模式相同。,压缩模式的功控,上行链路 压缩模式功控的目的是为了尽快恢复GAP之后的SIR到SIRtarget。NodeB根据SI

22、R与SIRtarget的大小产生TPC Cpmmand，压缩模式时用下面的公式计算SIRtarget： SIRcm_target = SIRtarget + SIRPILOT + SIR1_coding + SIR2_coding ; SIRPILOT = 10Log10 (Npilot,N/Npilot,curr_frame); Npilot,curr_frame ：当前压缩帧每个slot的导频比特数。 Npilot,N: ：正常帧每个slot的导频比特数。,压缩模式的功控,下行链路 下行每个非GAP的slot，UTRAN 估计第k个TPC 命令并且按照下面的公式调整当前下行发送功率 P(k-1) dB到一个新的值 P(k)dB： P(k) = P(k - 1) + PTPC(k) + PSIR(k) + Pbal(k); PTPC(k)：上行无TPC_cmd时，对应PTPC(k) = 0 ，否则按照正常模式计算， 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出现在RPL的结 束之前，那么RPL就停止于新的