【文章內(nèi)容簡介】 ndary Sync. Codes: Group of 256bit codesHelps UE achieve Frame Synchronization? Pilot Codes A fulltime mon Pilot (CPICH) provides coherent reference for UE receiver Pilot data bits are embedded into each timeslot of the Dedicated Data Channel ? Random Access Preamble Codes Preamble Signatures。 Used by BS to distinguish between UE making access attempts Preamble Scrambling Codes。 Used to identify which BS is being accessed184/038 13 EN/LZU 108 5306 Rev A WCDMA Air InterfaceWCDMA Downlink Physical Layer194/038 13 EN/LZU 108 5306 Rev A WCDMA Air InterfaceWCDMA Downlink (FDD)204/038 13 EN/LZU 108 5306 Rev A WCDMA Air InterfaceDownlink Logical Channels? Common Downlink Logical Channels BCCH (Broadcast Control Channel)– Broadcasts cell site and system identification to all UE PCCH (Paging Control Channel)– Transmits paging information to a UE when the UE’s location is unknown CCCH (Common Control Channel)– Transmits control information to a UE when there is no RRC Connection SHCCH (Shared Channel Control Channel)– Control channel associated with shared traffic channels (TDD mode only) CTCH (Common Traffic Channel)– Traffic channel for sending traffic to a group of UE’s.? Dedicated Downlink Logical Channels DCCH (Dedicated Control Channel)– Transmits control information to a UE when there is a RRC Connection DTCH (Dedicated Traffic Channel)– Traffic channel dedicated to one UE3GPP TS 182。 214/038 13 EN/LZU 108 5306 Rev A WCDMA Air InterfaceDownlink Transport Channels? Common Downlink Transport Channels BCH (Broadcast Channel)– Continuous transmission of system and cell information PCH (Paging Channel)– Carries control information to UE when location is unknown– Pending activity indicated by the PICH (paging indication channel) FACH (Forward Access Channel)– Used for transmission of idlemode control information to a UE– No closedloop power control DSCH (Downlink Shared Channel)– Carries dedicated control and/or traffic data。 shared by several UE’s? Dedicated Downlink Transport Channels DCH (Dedicated Channel)– Carries dedicated traffic and control data to one UE3GPP TS 182。 224/038 13 EN/LZU 108 5306 Rev A WCDMA Air InterfaceOVSF Codes? Downlink OVSF Channelization Codes11 11 11 1 1 11 1 1 11 1 1 11 1 1 1C1,0C2,0C2,1C4,0C4,1C4,2C4,3Designation: cch, SF , code numberSF = 1 SF = 2 SF = 43GPP TS 182。 234/038 13 EN/LZU 108 5306 Rev A WCDMA Air InterfaceCode Layering? WCDMA Code Layering 3GPP TS 182。 , 244/038 13 EN/LZU 108 5306 Rev A WCDMA Air InterfaceCommon Pilot Channel? Downlink CPICH (Common Pilot Channel)Pilot Symbol Data (10 symbols per slot)1 2 3 4 5 6 7 8 9 10 11 12 13 14 151 Frame = 15 slots = 10 mSec1 timeslot = 2560 Chips = 10 symbols = 20 bits = uSecA A A A A A A A A A A A A A A A A A A A A AA A AA A A A A A A A A A A A A A A A A A A A A AA A ASlot 0 Slot 1Slot 14Antenna 1SymbolsAntenna 2SymbolsIf transmit diversity is used, then the pilot symbols are as shown for each antenna:3GPP TS 182。 254/038 13 EN/LZU 108 5306 Rev A WCDMA Air InterfaceSync Channel / Primary Common Control Channel? Downlink SCH / PCCPCHBroadcast Data (18 bits)SSCiBCH Spreading Factor = 2561 Slot = mSec = 18 BCH data bits / slot1 2 3 4 5 6 7 8 9 10 11 12 13 14 151 Frame = 15 slots = 10 mSec2304 Chips256 ChipsSCH BCH3GPP TS 182。 PSC264/038 13 EN/LZU 108 5306 Rev A WCDMA Air InterfaceSecondary Common Control Channel? Downlink SCCPCHSpreading Factor = 256 to 41 Slot = mSec = 2560 chips = 20 * 2k data bits。 k = [0..6]1 2 3 4 5 6 7 8 9 10 11 12 13 14 151 Frame = 15 slots = 10 mSec20 to 1256 bits0, 2, or 8 bits3GPP TS 182。 DataTFCI or DTX Pilot0, 8, or 16 bits274/038 13 EN/LZU 108 5306 Rev A WCDMA Air InterfacePage Indication Channel? Paging Indication Channel (PICH)228。 Spread with SF=256 Channelization code228。 Each UE looks for a particular PICH time slot228。 A paging indicator set to “1” indicates that the UE should read the SCCPCH of the corresponding frame.b1b0288 bits for paging indication 12 bits (undefined)One radio frame (10 ms)b287 b288 b2993GPP TS 182。 284/038 13 EN/LZU 108 5306 Rev A WCDMA Air InterfaceDedicated Control/Data Channel? Downlink DPCCH/DPDCH FrameData 2TFCIData 1 TPC1 Slot = mSec = 2560 chips = 10 x 2^k bits, k = [0...7]SF = 512/2k = [512, 256, 128, 64, 32, 16, 8, 4]1 2 3 4 5 6 7 8 9 10 11 12 13 14 151 Frame = 15 slots = 10 mSecDPDCHPilotDPDCH DPCCH DPCCHThe DPDCH carries user traffic, layer 2 overhead bits, and layer 3 signaling data.The DPCCH carries layer 1 control bits: Pilot, TPC, and TFCIDownlink ClosedLoop Power Control steps of 1 dB, dB3GPP TS 182。 294/038 13 EN/LZU 108 5306 Rev A WCDMA Air InterfaceDownlink Data Rates? Variable Data Rates on the Downlink: ExamplesCoded Data Mb/sec(19,200 bits per 10 mSec frame)S/P ConverterChannel Coding(OVSF codes at Mcps)960 kb/sec304/038 13 EN/LZU 108 5306 Rev A WCDMA Air InterfaceDownlink DPDCH/DPCCH Slot Formats3GPP TS 182。 Notes:1) ZeroTFCI slot formats are used when there is only one data service on the DCH. 2) Slot formats A and B are used during pressed mode operation314/038 13 EN/LZU 108 5306 Rev A WCDMA Air InterfaceTimeEmbedded Pilot Symbols? DL: Timemultiplexed with DPDCH? UL: Transmitted on Qchannel along with TPC, TFCI, FBI bitsPilot Bit Patterns, Downlink DPDCH (Data Channel)3GPP TS 182。 Note:Shaded portions are the Frame Synchronization Words (FSW)324/038 13 EN/LZU 108 5306 Rev A WCDMA Air InterfaceTransmit Power Control (TPC) Bits? TPC Bits228。 2, 4, or 8 bits per slot depending on slot format3GPP TS 182。 Table 13334/038 13 EN/LZU 108 5306 Rev A WCDMA Air InterfaceTFCI Bit