WCDMA系统设计

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1、 一、W-CDMA物理层协议概述 二、W-CDMA系统设计实例 三、W-CDMA下行信道系统设计构想 四、硬件设计入门 1.W-CDMA协议概观(25.201) 2.传输信道和物理信道映射(25.211) 3.信道复用与信道编码(25.212) 4.扩频与调制模式(25.213) 5.物理层处理机制(25.214) 6.物理层测试规范(25.215)Radio Resource Control (RRC)Medium Access Control(MAC)Transport channelsPhysical layerControl / MeasurementsLayer 3Logical c

2、hannelsLayer 2Layer 1 W-CDMA(FDD)物理层协议关系模型 25.211 传输信道到 物理信道映射 25.212 复用和信道编码 25.213 扩频和调制 25.215 measurements 25.214 procedures +1/-1 traffic 0/1 +1/-1 control A.传输信道 B.物理信道与物理信号 C.信道映射 D.信道时序关系 A transport channel is defined by how and with what characteristics data is transferred over the air int

3、erface. A general classification of transport channels is into two groups: Dedicated channels, using inherent addressing of UE; Common channels, using explicit addressing of UE if addressing is needed. Dedicated Channel: DCH Common Transport Channel: BCH - Broadcast ChannelFACH - Forward Access Chan

4、nelPCH - Paging ChannelRACH - Random Access ChannelCPCH - Common Packet ChannelDSCH - Downlink Shared Channel Function of DCH The Dedicated Channel (DCH) is a downlink or uplink transport channel. The DCH is transmitted over the entire cell or over only a part of the cell using e.g. beam-forming ant

5、ennas. Function of Common Transport Channel The Broadcast Channel (BCH) is a downlink transport channel that is used to broadcast system- and cell-specific information. The BCH is always transmitted over the entire cell and has a single transport format. The Forward Access Channel (FACH) is a downli

6、nk transport channel. The FACH is transmitted over the entire cell or over only a part of the cell using e.g. beam-forming antennas. The FACH can be transmitted using slow power control. The Paging Channel (PCH) is a downlink transport channel. The PCH is always transmitted over the entire cell. The

7、 transmission of the PCH is associated with the transmission of physical-layer generated Paging Indicators, to support efficient sleep-mode procedures. The Random Access Channel (RACH) is an uplink transport channel. The RACH is always received from the entire cell. The RACH is characterized by a co

8、llision risk and by being transmitted using open loop power control. The Common Packet Channel (CPCH) is an uplink transport channel. CPCH is associated with a dedicated channel on the downlink which provides power control and CPCH Control Commands (e.g. Emergency Stop) for the uplink CPCH. The CPCH

9、 is characterised by initial collision risk and by being transmitted using inner loop power control. The Downlink Shared Channel (DSCH) is a downlink transport channel shared by several UEs The DSCH is associated with one or several downlink DCH. The DSCH is transmitted over the entire cell or over

10、only a part of the cell using e.g. beam-forming antennas. Indicators are means of fast low-level signalling entities which are transmitted without using information blocks sent over transport channels. The meaning of indicators is implicit to the receiver. The indicators defined in the current versi

11、on of the specifications are: Acquisition Indicator (AI), Access Preamble Indicator (API), Channel Assignment Indicator (CAI), Collision Detection Indicator (CDI), Page Indicator (PI) and Status Indicator (SI). Physical channels are defined by a specific carrier frequency, scrambling code, channeliz

12、ation code (optional), time start & stop (giving a duration) and, on the uplink, relative phase (0 or /2). Slot: 2560 chips Radio frame: 15 slots 38400 chips Transport channels can be mapped to physical channels. Within the physical layer itself the exact mapping is from a composite coded transport

13、channel (CCTrCH) to the data part of a physical channel. In addition to data parts there also exist channel control parts and physical signals. Physical signals Physical signals are entities with the same basic on-air attributes as physical channels but do not have transport channels or indicators m

14、apped to them. Physical signals may be associated with physical channels in order to support the function of physical channels.专用物理信道(DPCH)下行物理信道上行物理信道公用物理信道物理随机接入信道(PRACH)物理公共分组信道(PCPCH)主公共控制物理信道(P-CCPCH)捕获指示信道(AICH)寻呼指示信道(PICH)物理下行共享信道(PDSCH)专用物理信道(DPCH)公用物理信道物理信道物理信道分类物理信道分类辅助公共控制物理信道(S-CCPCH)CPC

15、H状态信道(CSICH)同步信道(SCH)接入前缀捕获指示信道(AP-AICH)碰撞检测/信道指配指示信道(CD/CA-ICH)公用导频信道(CPICH)Uplink physical channels Dedicated uplink physical channels There are two types of uplink dedicated physical channels, the uplink Dedicated Physical Data Channel (uplink DPDCH) and the uplink Dedicated Physical Control Chan

16、nel (uplink DPCCH). The DPDCH and the DPCCH are I/Q code multiplexed within each radio frame (see 4). The uplink DPDCH is used to carry the DCH transport channel. There may be zero, one, or several uplink DPDCHs on each radio link.Pilot Npilot bitsTPC NTPC bitsDataNdata bitsSlot #0Slot #1Slot #iSlot

17、 #14Tslot = 2560 chips, 10 bits1 radio frame: Tf = 10 msDPDCHDPCCHFBI NFBI bitsTFCI NTFCI bitsTslot = 2560 chips, Ndata = 10*2k bits (k=0.6)Frame structure for uplink DPDCH/DPCCH物理随机接入信道（物理随机接入信道（PRACHPRACH） M essage part Pream ble 4096 chips 10 m s (one radio fram e) Pream ble Pream ble M essage pa

18、rt Pream ble 4096 chips 20 m s (tw o radio fram es) Pream ble Pream ble D a ta Nd a ta b its S lo t # 0 S lo t # 1 S lo t # i S lo t # 14 Tslo t = 2560 c h ip s , 10 b its D a ta C o n tro l Tslo t = 2560 c h ip s , Nd a ta = 10* 2k b its (k= 0.3) P ilo t Np ilo t b its T F C I NT FC I b its M e s s

19、 a g e p a rt ra d io fra m e TR A C H = 10 m s Structure of the random-access message part radio framePilot Npilot bitsDataNdata bitsSlot #0Slot #1Slot #iSlot #14Tslot = 2560 chips, 10*2k bits (k=0.3)Message part radio frame TRACH = 10 msDataControlTFCI NTFCI bits Physical Common Packet Channel (PC

20、PCH) The CPCH transmission is based on DSMA-CD approach with fast acquisition indication.Downlink physical channels Downlink transmit diversity Space time block coding based transmit antenna diversity (STTD) Time Switched Transmit Diversity for SCH (TSTD)Dedicated downlink physical channels Dedicate

21、d Physical Channel(DPCH) Within one downlink DPCH, dedicated data generated at Layer 2 and above, i.e. the dedicated transport channel (DCH), is transmitted in time-multiplex with control information generated at Layer 1 (known pilot bits, TPC commands, and an optional TFCI). The downlink DPCH can t

22、hus be seen as a time multiplex of a downlink DPDCH and a downlink DPCCH.One radio frame, Tf = 10 msTPC NTPC bitsSlot #0Slot #1Slot #iSlot #14Tslot = 2560 chips, 10*2k bits (k=0.7)Data2Ndata2 bitsDPDCHTFCI NTFCI bitsPilot Npilot bitsData1Ndata1 bitsDPDCHDPCCHDPCCH下行专用物理信道帧结构（下行专用物理信道帧结构（DPCHDPCH） 1

23、2 L D P D C H O n e S lo t (2 5 6 0 c h ip s ) T F C I P ilo t T P C D P D C H 下行下行DPCHDPCH的多码传输的多码传输Common downlink physical channels Common Pilot Channel (CPICH) The CPICH is a fixed rate (30 kbps, SF=256) downlink physical channel that carries a pre-defined bit/symbol sequence. Include: Primary C

24、ommon Pilot Channel (P-CPICH) Secondary Common Pilot Channel (S-CPICH) 发射预先定义好的已知序列，A1j 固定传输速率30Kbps， SF=256 发射分集时，两根天线上发射的信号使用相同的扩频码和扰码，但传送序列有所不同。 主要用于信道估计slot #1Frame#i+1Frame#islot #14A A A A A A A A A A A A A A A A A A A A A A A A-A -A A A -A -A A A -A A -A -A A A -A -A A A -A -A A A -A -AAntenn

25、a 2Antenna 1slot #0Frame Boundary公共导频信道（公共导频信道（CPICHCPICH） 主CPICH 使用相同的信道码,即Cch,256,0 扰码为主扰码 一个小区只有一个主CPICH 在整个小区广播 辅助CPICH 可以使用任意信道码，只要满足 SF=256 扰码可以使用主扰码，也可以使用辅助扰码 一个小区可以有0、1或几个辅助扰码 可以在小区内部分发射主主CPICHCPICH与辅助与辅助CPICHCPICH的区别的区别 Primary Common Control Physical Channel (P-CCPCH) The Primary CCPCH is

26、a fixed rate (30 kbps, SF=256) downlink physical channels used to carry the BCH transport channel. The Primary CCPCH is not transmitted during the first 256 chips of each slot. Instead, Primary SCH and Secondary SCH are transmitted during this period. Secondary Common Control Physical Channel (S-CCP

27、CH) The Secondary CCPCH is used to carry the FACH and PCH. Physical Downlink Shared Channel (PDSCH) The Physical Downlink Shared Channel (PDSCH) is used to carry the Downlink Shared Channel (DSCH). PDSCH承载 DSCH, 被多个码分用户分时共享。 PDSCH 总是与一个 DPCH相伴随，所需控制信息在所伴随的DPCH的DPCCH上传输。DSCH上传的是纯数据，效率很高，适合处理短时高速率突发业务

28、，是特殊形式的多码传输，但高层控制起来比较复杂。 Slot #0 Slot #1 Slot #i Slot #14 Tslot = 2560 chips, 20*2k bits (k=0.6) Data Ndata1 bits 1 radio frame: Tf = 10 ms 物理下行共享信道（物理下行共享信道（PDSCHPDSCH） Data Ndata1=18 bits Slot #0 Slot #1 Slot #i Slot #14 Tslot = 2560 chips , 20 bits 1 radio frame: Tf = 10 ms (Tx OFF) 256 chips 主公共

29、控制物理信道（主公共控制物理信道（P-CCPCHP-CCPCH） 固定为30Kbps （SF=256）的传输速率，用于承载BCH。 每个时隙的头256chips为空，到时候由SCH填充；或者说P-CCPCH与SCH时分复用。 Slot #0 Slot #1 Slot #i Slot #14 Tslot = 2560 chips, 20*2k bits (k=0.6) Pilot Npilot bits Data Ndata1 bits 1 radio frame: Tf = 10 ms TFCI NTFCI bits 辅助公共控制物理信道（辅助公共控制物理信道（S-CCPCHS-CCPCH）

30、用于承载FACH和PCH，可分别承载FACH和PCH，也可两者同时承载。 TFCI可有可无，由上层决定；没有TPC，采用开环功控；导频为8或16比特。 传输能力比下行DPCH稍逊，SF为2564。 Acquisition Indicator Channel (AICH) The Acquisition Indicator channel (AICH) is a fixed rate (SF=256) physical channel used to carry Acquisition Indicators (AI). Acquisition Indicator AIs corresponds

31、to signature s on the PRACH. Paging Indicator Channel (PICH) The Paging Indicator Channel (PICH) is a fixed rate (SF=256) physical channel used to carry the Paging Indicators (PI). The PICH is always associated with an S-CCPCH to which a PCH transport channel is mapped. 1024 chipsTransmission OffAS

32、#14AS #0AS #1AS #iAS #14AS #0a1a2a0a31a30AI part = 4096 chips, 32 real-valued symbols20 ms捕获指示信道（捕获指示信道（AICHAICH）n AICH每一帧为20 ms，分成15个接入时隙AS, 每个时隙有20个符号(5120码片)。每个时隙包括两部分，捕获指示AI部分（4096码片）和空部分（1024码片） 。n 16个AI分别对16种签名进行应答，AI1、1和0分别代表同意接入、不同意接入和没有听到请求。n aj是由16个AI和16个签名进行矩阵运算得到。寻呼指示信道（寻呼指示信道（PICHPICH）b

33、1b0288 bits for paging indication12 bits (transmissionoff)One radio frame (10 ms)b287b288b299n PICH为固定速率(SF=256)的物理信道，用于承载寻呼指示 (PI).n PICH 总是与S-CCPCH 相伴随，如果某一帧中的 PIi 被置为1，说明Pii所对应的UE应对S-CCPCH的对应帧进行解调。n PICH一帧为10ms，包括300bits。其中，288 比特用于传送 PI， 其余12 比特尚未定义，不发射。n 一帧内传送N 个寻呼指示PI，N=18, 36, 72, or 144。 CPC

34、H Status Indicator Channel (CSICH) The CPCH Status Indicator Channel (CSICH) is a fixed rate (SF=256) physical channel used to carry CPCH status information. Synchronisation Channel (SCH) The Synchronisation Channel (SCH) is a downlink signal used for cell search. The SCH consists of two sub channel

35、s, the Primary and Secondary SCH.同步信道（同步信道（SCHSCH）SCH用于小区搜索，分成主同步信道（ P-SCH）和辅助同步信道（S-SCH），两者并行发射。 SCH占用每个无线帧的前256个码片，与P-CCPCH时分复用。主同步码 (PSC) 以时隙为周期发射，用于时隙同步；辅助同步码以无线帧为周期发射，用于帧同步，并指出小区主扰码的组号。a为一个指示调制信号，用于指示P-CCPCH是否采用了STTD。 Primary SCH Secondary SCH 256 chips 2560 chips One 10 ms SCH radio frame acsi

36、,0 acp acsi,1 acp acsi,14 acp Slot #0 Slot #1 Slot #14 C.物理信道映射Transport ChannelsDCHRACHCPCHBCHFACHPCHDSCHPhysical ChannelsDedicated Physical Data Channel (DPDCH)Dedicated Physical Control Channel (DPCCH)Physical Random Access Channel (PRACH)Physical Common Packet Channel (PCPCH)Common Pilot Channel

37、 (CPICH)Primary Common Control Physical Channel (P-CCPCH)Secondary Common Control Physical Channel (S-CCPCH)Synchronisation Channel (SCH)Physical Downlink Shared Channel (PDSCH)Acquisition Indicator Channel (AICH)Access Preamble Acquisition Indicator Channel (AP-AICH)Paging Indicator Channel (PICH)C

38、PCH Status Indicator Channel (CSICH)Collision-Detection/Channel-Assignment IndicatorChannel (CD/CA-ICH)Channel-Assignment Indication Channel (CA-ICHPhysical SignalsPRACH preamble partPCPCH accesspreamble partPCPCH CD/CApreamble partPCPCH power controlpreamble partPhysical ChannelsPhysical Random Acc

39、ess Channel (PRACH)Physical Common Packet Channel (PCPCH)D.物理信道的时序关系AICH accessslotsSecondarySCHPrimarySCHS-CCPCH,k10 msPICH#0#1#2#3#14#13#12#11#10#9#8#7#6#5#4P-CCPCH, (SFN modulo 2) = 0P-CCPCH, (SFN modulo 2) = 1Any CPICHk:th S-CCPCHPICH for k:th S-CCPCHn:th DPCHDPCH,nAny PDSCH信道匹配与信道编码 CRC码 卷积码 Tu

40、rbo码 TFCI 交织10、20、40 or 80msdatadatadataTrCH-idataCRCdataCRCdataCRCdataCRCdataCRCdataCRCd a t aCBLCBLCBL0、8、12、16 or 24bits块长 Z504 ， 卷积码5114 ，Turbo码CedBLCedBLCedBLCoded data卷积码 或 Turbo码Rate matched dataRate matched dataDTXororData before 1st interleavingData after 1st interleaved交织器列数：1、2、4 或 8无线帧无线

41、帧无线帧无线帧数目：1、2、4 或 8TrCH-1TrCH-2TrCH-ICCTrCHTrCH-1 TrCH-2TrCH-IDTXCCTrCHPh-1Ph-2Ph-P10ms时间内10ms时间内Ph-1Ph-2Ph-PTPC TFCIpilot扩频、加扰扩频、加扰扩频、加扰TrCH-i+1data1data2data1data2data1data2下下行行信信道道编编码码与与复复用用CRC校验 The entire transport block is used to calculate the CRC parity bits for each transport block. The par

42、ity bits are generated by one of the following cyclic generator polynomials: gCRC24(D) = D24 + D23 + D6 + D5 + D + 1; gCRC16(D) = D16 + D12 + D5 + 1; gCRC12(D) = D12 + D11 + D3 + D2 + D + 1; gCRC8(D) = D8 + D7 + D4 + D3 + D + 1.纠错编码技术纠错编码技术 卷积码卷积码 纠错编码技术是在发射端按一定规则引入冗余信息，从而使得即使空中传输引入了误码，也能利用冗余信息将此错误纠

43、正回来的技术。 在WCDMA系统中主要用于话音信道和控制信道，编码速率为1/2和1/3。卷积码特点：译码简单，时延小，一般采用维特比算法，信道误码率在103，适合实时业务，如话音和视频业务的传送。Output 0 G0 = 557 (octal) Input D D D D D D D D Output 1 G1 = 663 (octal) Output 2 G2 = 711 (octal) Rate 1/3 convolutional coder WCDMA中的卷积码 Convolutional codes with constraint length 9 and coding rates

44、1/3 and 1/2 are defined.Output 0G0 = 557 (octal)InputDDDDDDDDOutput 1G1 = 663 (octal)Output 2G2 = 711 (octal)Output 0G0 = 561 (octal)InputDDDDDDDDOutput 1G1 = 753 (octal)(a) Rate 1/2 convolutional coder(b) Rate 1/3 convolutional coder纠错编码技术纠错编码技术 TurboTurbo码码 在WCDMA系统中主要用于数据业务信道，编码速率为1/3，分组长度最大到5114

45、比特，可以实现大分组，时延长的业务传送。TURBO码的特点：译码复杂，常采用LOGMAP算法，信道误码率可以达到106，非常适合对误码率敏感，而对时延不敏感的非实时分组业务，如WWW，FTP，EMAIL等多媒体业务传送。 xk xk zk Turbo code internal interleaver xk zk D D D D D D Input O utput Input O utput xk 1st constituent encoder 2nd constituent encoder The scheme of Turbo coder is a Parallel Concatenate

46、d Convolutional Code (PCCC) with two 8-state constituent encoders and one Turbo code internal interleaver. The coding rate of Turbo coder is 1/3. transfer function:G(D) = g0(D) = 1 + D2 + D3,g1(D) = 1 + D + D3. WCDMA中的Turbo码)()(, 101DgDgxkxkzkTurbo codeinternal interleaverxkzkDDDDDDInputOutputInputO

47、utputxk1st constituent encoder2nd constituent encoder交织技术交织技术在通信系统中，为了减少突发干扰对连续数据造成的大面积差错，常采用交织交织来将突发干扰造成的连续差错化解为随机独立差错，使其适合于译码器的错误纠正。交织，就是打乱原来的数据排列规则，按照一定顺序重新排列。缺点： 带来了附加的额外延时 在特殊情况下，若干个随机独立差错有可能交织为突发差错。x1 x6 x11 x16 x21x2 x7 x22x3 x8 x23x4 x9 x24x5 x10 x25输入数据 A = (x1 x2 x3 x4 x5 x25)输出数据 A= (x1 x

48、6 x11 x16 x25)举例：交织技术（续）交织技术（续）交织器根据采用的技术不同，又可分为多种，如分组交织器、随机交织器、循环移位交织器、半随机交织器、奇偶交织器、均匀交织器等。WCDMA系统采用了分组交织器（又称矩形交织器）和均匀交织器两种技术。分组交织器在第一次交织（帧间交织）和第二次交织（帧内交织）中用到，特点是方式简单、对短序列交织效果较好，但交织后码元的去相关不彻底。均匀交织器在Turbo编码中用到，其特点是交织算法复杂，但去相关较彻底。复用技术复用技术复用技术是指将具有相同或不同QoS要求的业务复用到一个物理信道中进行传输的技术。由于业务种类及其QoS要求千变万化，但物理信道

49、的能力只是有限的几个等级。如何在保证各种业务QoS要求的前提下高效地复用到一个物理信道中传输是复用算法首要考虑的问题。这就牵涉到速率匹配的问题，它是复用技术的核心之所在，同时还牵涉到信道编码方案等其它技术的选用问题。业务3业务2业务1业务4TFCI The TFCI is encoded using a (32, 10) sub-code of the second order Reed-Muller code. The code words of the (32,10) sub-code of second order Reed-Muller code are linear combinat

50、ion of 10 basis sequences. The basis sequences are as in the following table 7.(32,10) sub-code ofsecond orderReed-Muller codeTFCI codewordb0.b31TFCI(10 bits)a0.a9扩频与调制模式 Uplink spreading and modulation OVSF Scramble sequence Preamble sequenceIjcd ,1dSd p ch ,nI+ jQD P D C H1Qcd ,3dD P D C H3cd ,5dD

51、 P D C H5cd ,2dD P D C H2cd ,4dD P D C H4cd ,6dD P D C H6cccD P C C HSSpreading for uplink DPCCH and DPDCHsSpreading of PRACH message partjccccddSr-msg,nI+jQPRACH messagecontrol partPRACH messagedata partQISOrthogonal Variable Spreading Factor (OVSF) codesSF = 1SF = 2SF = 4Cch,1,0 = (1)Cch,2,0 = (1,

52、1)Cch,2,1 = (1,-1)Cch,4,0 =(1,1,1,1)Cch,4,1 = (1,1,-1,-1)Cch,4,2 = (1,-1,1,-1)Cch,4,3 = (1,-1,-1,1)Scrambling codes Long scrambling sequence xn(i+25) =xn(i+3) + xn(i) modulo 2, i=0, 225-27. y(i+25) = y(i+3)+y(i+2) +y(i+1) +y(i) modulo 2, i=0, 225-27. Short scrambling sequence used to MUD Configurati

53、on of uplink scrambling sequence generatorclong,1,nclong,2,nMSBLSBModulationSImSReScos(t)Complex-valuedchip sequencefrom spreadingoperations-sin(t)Splitreal &imag.partsPulse-shapingPulse-shapingDownlink spreading and modulationIAny downlinkphysical channelexcept SCHSPCch,SF,mjSdl,nQI+jQSSpreading fo

54、r all downlink physical channels except SCHDifferent downlinkPhysical channels(point S in Figure 8) G1G2GPGSS-SCHP-SCH (point T inFigure 11)Spreading and modulation for SCH and P-CCPCHChannelization codes The channelization codes are the same codes as used in the uplink, namely Orthogonal Variable S

55、preading Factor (OVSF) codes that preserve the orthogonality between downlink channels of different rates and spreading factors. The channelization code for the Primary CPICH is fixed to Cch,256,0 and the channelization code for the Primary CCPCH is fixed to Cch,256,1.The channelization codes for al

56、l other physical channels are assigned by UTRAN. Dynamic Code Allocation AlgorithmScrambling code x(i+18) =x(i+7) + x(i) modulo 2, i=0,218-20. y(i+18) = y(i+10)+y(i+7)+y(i+5)+y(i) modulo 2, i=0, 218-20.IQ1100223344556677889917171616151514141313121211111010Configuration of downlink scrambling code ge

57、neratorSynchronisation codes The primary synchronisation code (PSC), Cpsc is constructed as a so-called generalised hierarchical Golay sequence. The PSC is furthermore chosen to have good aperiodic auto correlation properties. a = = The PSC is generated by repeating the sequence a modulated by a Gol

58、ay complementary sequence, and creating a complex-valued sequence with identical real and imaginary components. The PSC Cpsc is defined as: Cpsc = (1 + j) ; The 16 secondary synchronization codes (SSCs), Cssc,1,C ssc,16, are complex-valued with identical real and imaginary components, and are constr

59、ucted from position wise multiplicationof a Hadamard sequence and a sequence z, defined as: z = , where b = and x1, x2 , , x15, x16, are same as in the definition of the sequence a above. The Hadamard sequences are obtained as the rows in a matrix H8 constructed recursively by: The rows are numbered

60、 from the top starting with row 0 (the all ones sequence). Denote the n:th Hadamard sequence as a row of H8 numbered from the top, n = 0, 1, 2, , 255, in the sequel.1,) 1 (11110kHHHHHHkkkkk Furthermore, let hn(i) and z(i) denote the i:th symbol of the sequence hn and z, respectively where i = 0, 1,

61、2, , 255 and i = 0 corresponds to the leftmost symbol. The k:th SSC, Cssc,k, k = 1, 2, 3, , 16 is then defined as: -Cssc,k = (1 + j) ; where m = 16(k 1) and the leftmost chip in the sequence corresponds to the chip transmitted first in time.Code allocation of SSC The 64 secondary SCH sequences are c

62、onstructed such that their cyclic-shifts are unique, i.e., a non-zero cyclic shift less than 15 of any of the 64 sequences is not equivalent to some cyclic shift of any other of the 64 sequences. Also, a non-zero cyclic shift less than 15 of any of the sequences is not equivalent to itself with any

63、other cyclic shift less than 15. Following table describes the sequences of SSCs used to encode the 64 different scrambling code groups. The entries in table 4 denote what SSC to use in the different slots for the different scrambling code groups, e.g. the entry 7 means that SSC Cssc,7 shall be used

64、 for the corresponding scrambling code group and slot.slot num berS cram blin gC ode G roup#0#1#2#3#4#5#6#7#8#9 #10 #11 #12 #13 #14G roup 0112891015810162715716G roup 111516731416310512141210G roup 212115551216611216111512G roup 3123186525844637G roup 412166611155121151216112G roup 5134741553628768G

65、 roup 6141134109211210121293G roup 715661491021392514113G roup 816101041171316111364116ModulationTImTReTcos(t)Complex-valuedchip sequencefrom summingoperations-sin(t)Splitreal &imag.partsPulse-shapingPulse-shaping物理层处理 Cell search procedure During the cell search, the UE searches for a cell and dete

66、rmines the downlink scrambling code and frame synchronisation of that cell. The cell search is typically carried out in three steps: Step 1: Slot synchronisation During the first step of the cell search procedure the UE uses the SCHs primary synchronisation code to acquire slot synchronisation to a cell. continue This is typically done with a single matched filter (or any similar device) matched to the primary synchronisation code which is common to all cells. The slot timing of the cell can be