W-CDMA系统物理层技术介绍、设计和同步设计实现优化实例W-CDMA系统设计一、W-CDMA(FDD)物理层协议概述1.W-CDMA协议概观W-CDMA(FDD)物理层协议关系模型2.传输信道与物理信道映射A.传输信道传输信道分类FunctionofDCHTheDedicatedChannel(DCH)isadownlinkoruplinktransportchannel.TheDCHistransmittedovertheentirecelloroveronlyapartofthecellusinge.g.beam-formingantennas.FunctionofCommonTransportChannelTheBroadcastChannel(BCH)isadownlinktransportchannelthatisusedtobroadcastsystem-andcell-specificinformation.TheBCHisalwaystransmittedovertheentirecellandhasasingletransportformat.ContinueContinueContinueIndicatorB.物理信道与物理信号PhysicalsignalsPhysicalsignalsareentitieswiththesamebasicon-airattributesasphysicalchannelsbutdonothavetransportchannelsorindicatorsmappedtothem.Physicalsignalsmaybeassociatedwithphysicalchannelsinordertosupportthefunctionofphysicalchannels.UplinkphysicalchannelsFramestructureforuplinkDPDCH/DPCCH物理随机接入信道（PRACH）Structureoftherandom-accessmessagepartradioframePhysicalCommonPacketChannel(PCPCH)TheCPCHtransmissionisbasedonDSMA-CDapproachwithfastacquisitionindication.DownlinkphysicalchannelsDedicateddownlinkphysicalchannels下行专用物理信道帧结构（DPCH）下行DPCH的多码传输Commondownlinkphysicalchannels发射预先定义好的已知序列，A＝1＋j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PrimaryCommonControlPhysicalChannel(P-CCPCH)ThePrimaryCCPCHisafixedrate(30kbps,SF=256)downlinkphysicalchannelsusedtocarrytheBCHtransportchannel.ThePrimaryCCPCHisnottransmittedduringthefirst256chipsofeachslot.Instead,PrimarySCHandSecondarySCHaretransmittedduringthisperiod.SecondaryCommonControlPhysicalChannel(S-CCPCH)TheSecondaryCCPCHisusedtocarrytheFACHandPCH.PhysicalDownlinkSharedChannel(PDSCH)ThePhysicalDownlinkSharedChannel(PDSCH)isusedtocarrytheDownlinkSharedChannel(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，是特殊形式的多码传输，但高层控制起来比较复杂。主公共控制物理信道（P-CCPCH）辅助公共控制物理信道（S-CCPCH）AcquisitionI