LTE物理层综合介绍ppt课件.ppt

AComprehensiveAnalysisOfLTEPhysicalLayer MasterofScienceThesisFahimehRezaeiSupervisor Dr HamidSharif Kashani Dr MichaelHempelDepartmentofComputerandElectronicsEngineeringUniversityofNebraska LincolnDecember 1st2010 Outline BackgroundLTEGeneralArchitectureThesisObjectiveandMotivationLiteratureReviewLTEPhysicalLayerCharacteristicsPerformanceStudyApproachSimulationResultsandAnalysisSummaryandConclusion BackgroundLTEGeneralArchitectureThesisObjectiveandMotivationLiteratureReviewLTEPhysicalLayerCharacteristicsPerformanceStudyApproachSimulationResultsandAnalysisSummaryandConclusion Background Standarddevelopers 3GPP IEEE and3GPP23rdGenerationStandards LongTermEvolution LTERelease8 802 16e WiMAX 802 16mUMB4thGenerationstandardsSatisfyIMT AdvancedRequirements 100Mbpsinhighmobility 300km h and1Gbpsinlowmobility 3km h lessthan5msDataLatency LTERelease8GeneralFeatures PacketSwitchedNetworkOFDMinDownlinkandSC FDMAinUplinkDuplexSchemes TDDandFDDAdoptiveModulationandCodingscheme QPSK 16 QAM 64 QAM MultipleAntennaTechniquesTransmitDiversitySingleUserMIMOMultiUserMIMOClose Looprank1precodingdedicatedbeamformingSystemBandwidthfrom1 4MHzto20MHz 1 4 3 5 10 15 20 BackgroundLTEGeneralArchitectureThesisObjectiveandMotivationLiteratureReviewLTEPhysicalLayerCharacteristicsPerformanceStudyApproachSimulationResultsandAnalysisSummaryandConclusion GeneralArchitecture LongTermEvolutionassociatedwithradioaccesstechnologySystemArchitectureEvolution SAE associatedwiththecorenetworkLTEarchitecture EPS E UTRAN EUTRANode LTEEPC EvolvedPacketCore SAE UserPlaneandControlPlaneProtocolStacks BackgroundLTEGeneralArchitectureThesisObjectiveandMotivationLiteratureReviewLTEPhysicalLayerCharacteristicsPerformanceStudyApproachSimulationResultsandAnalysisSummaryandConclusion ThesisObjectiveandMotivations Arethesevaluesaccurateorevencorrect Istherightapproachusedforgettingproposedvaluesandresults Inwhichconditionsandscenariospresentedvaluesandresultsarevalid ThesisObjectiveandMotivations cnt ProvidetherightapproachforevaluationofphysicallayerperformanceProvideaperformancestudythatincludesallpossiblescenarioswhichisaddressesbyDifferentantennadiversitymodesDifferentmodulationschemesandcoderatesIncludebothFDDandTDDoperationsIncludeallchannelbandwidthsUnderstandingtheperformanceevaluationapproachesusedbefore LiteratureReview ProfoundunderstandingofPhysicallayerStructuretodetermineresourceallocationusedfordataandcontrolinformationtransmission LTEPhysicalLayerConfiguration Implementingthephysicallayerproceduretoprovideanaccuratesimulationmodel Performancestudyapproachandsimulationresults BackgroundLTEGeneralArchitectureThesisObjectiveandMotivationLiteratureReviewLTEPhysicalLayerCharacteristicsPerformanceStudyApproachSimulationResultsandAnalysisSummaryandConclusion LiteratureReview J J S nchez D Morales Jim nez G G mez J T Enbrambasaguas PhysicalLayerPerformanceofLongTermEvolutionCellularTechnology 16thISTMobileandWirelessCommunicationsSummit 2007 ThispapermainlyfocusesonoutliningtheimpactofdifferentfeaturesofLTEonperformance However atthetimeofthispublication somecharacteristicsofLTEwereunderdevelopment e g channelcodingandratematching 4x4MIMO D M Sacrist n J Cabrejas D Calabuig J F Monserrat InstituteofTelecommunicationsandMultimediaApplications MACLayerPerformanceofDifferentChannelEstimationTechniquesinUTRANLTEDownlink 69th IEEE VTCPerformancestudyislimitedtodownlinktransmission Simulationresultsarebasedon10MHzsystembandwidth onetransmitandtworeceiveantenna SIMO LiteratureReview cnt D M Sacrist n J F Monserrat J Cabrejas D Calabuig S Garrigas N Cardona OntheWaytowardsFourth GenerationMobile 3GPPLTEandLTE Advanced EURASIPJournalonWirelessCommunicationsandNetworking July2009Thispaperalsopresentsaperformanceanalysisfor10MHzofchannelbandwidth MIMO4x4and2x2indownlinkandMIMO1x2inuplinkcases Themaximumthroughputofthedownlinkanduplinkisstatedtobearound130Mbpsand40Mbps respectively 2OFDMsymbolforPDCCHand C Ball T Hindelang I Kambourov S Eder SpectralEfficiencyAssessmentandRadioPerformanceComparisonbetweenLTEandWiMAX 2008IEEEPerformancecomparisonofLTEandWiMAXislimitedtoDownlinkFDDscenario notexcludingcontrolinformation MaximumDownlinkThroughput 120Mbps 2x2MIMO 3GPPR1 072261 LTEPerformanceEvaluation UplinkSummary May2007 3GPPR1 072578 SummaryofDownlinkPerformanceEvaluation May2007 MaximumDownlinkMaximumThroughput 326 4MbpsMaximumUplinkThroughput 86 4Mbps BackgroundLTEGeneralArchitectureThesisObjectiveandMotivationLiteratureReviewLTEPhysicalLayerCharacteristicsPerformanceStudyApproachSimulationResultsandAnalysisSummaryandConclusion LTETransmissionProcedure PhysicalLayerStructure Ts 1 15000 2048 2048istheFFTlengthFramesize 10ms is307200 Ts Subframe 1ms slot 0 5msAspecialsubframedoesnotexistinsecondhalfframeswith10msdownlinktouplinkswitchpointperiodicity PhysicalLayerStructure cnt DownlinkPhysicalChannels PDSCH PhysicalDownlinkShareChannelThisphysicalchannelisutilizedfortransmissionofuserdata broadcastsysteminformationthatisnottransmittedbyPBCH andpagingmessagesQPSK 16QAM and64 QAMPBCH PhysicalBroadcastChannelPhysicalbroadcastchannelcontainsbasicinformationforUEtoaccessthecell72subcarriersand4OFDMsymbols QPSKModulation PDCCH PhysicalDownlinkControlChannelThischannelconveysUEspecificcontrolinformationsuchasschedulingassignment resourceallocationofphysicalchannels andHARQinformationItcanoccupy1to4OFDMsymbolsbasedonChannelConditions antennaports QPSKmodulationPCFICH PhysicalControlFormatIndicatorChannelThenumberofOFDMsymbolsthatusedforPDCCHtransmissionineachsubframeisspecifiedbyPCFICH16resourceelementsinthefirstOFDMsymbolQPSKmodulationPHICH PhysicalHybridARQIndicatorChannelWheneNBreceivesatransmissiononthePUSCH itsendsbackACK 0forpositiveAcknowledgement andNACK 1forNegativeAcknowledgement throughPHAICHBPSKModulationPMCH PhysicalMulticastChannelMultimediaBroadcastandMulticastServices MBMS areavailableinlaterreleasesofLTEsuchasRelease9and10 DownlinkReferenceSignals P SS PrimarySynchronizationSignalP SSprovidesslottiminginformationandPhysicallayerIDforUE2OFDMSymbolsareassignedforP SSS SS SecondarySynchronizationSignalS SSutilizesUEwiththeinformationofcellID cyclicprefixlength andwhethertheeNBisworkingbasedonTDDorFDDoperations 2OFDMSymbolsareassignedforS SSRS ReferenceSignalReferencesignals RSs inLTEareusedforchannelestimationandaresentonparticularresourceelementsbyapredefinedstructureCell specificRSsthatareavailabletoallUEsinthecellandalsoknownascommonRSs UE specificRSsthatareusedforspecificUEsMBSFN specificRSsthatareusedforMBFSNoperations UplinkPhysicalChannelsandReferenceSignal PUSCH PhysicalUplinkShareChannelUplinkDatatransmission QPSK 16 QAM and64 QAMPUCCH PhysicalUplinkControlChannelControlinformationsuchasHARQACK NACK CQI 6formatsbasedontheinformationthatthischannelcontainsPRACH PhysicalRandomAccessChannelProvidesrandomaccessoperationfornon SynchronousUEsorUEsthatlosttheirsynchronizationDemodulationReferenceSignalsD RS PUSCHandD RS PUCCHChannelestimationandcoherentdemodulationOccupiesthesamebandwidthasitsassociatedphysicalchannelS RS SoundingReferenceSignalThisreferencesignalismainlyusedforchannelqualityestimationforfrequencyselectiveschedulingorprovidinginitializationandset upfunctionsforUEsthatarenotscheduled Downlinkanduplinkphysical transportandlogicalchannelmapping LogicalChannels TransportChannels PhysicalChannels BackgroundLTEGeneralArchitectureThesisObjectiveandMotivationLiteratureReviewLTEPhysicalLayerCharacteristicsPerformanceStudyApproachSimulationResultsandAnalysisSummaryandConclusion FDDDownlinkPhysicalLayerOutline FDDUplinkPhysicalLayerOutline TDDPhysicalLayerOutline FDDPDSCHMaximumREs Oneantennaport Twoantennaports Fourantennaports Incaseof4antennaports 1OFDMsymbolassignedforPDCCH and64 QAMmodulationscheme throughputis325 132Mbps Byapplyingthemaximumcoderate 0 92 thethroughputis299 122Mbps FDDPUSCHMaximumREs Using64 QAMmodulationschemeforPUSCHdata thethroughputis 84 672MbpsByapplyingthemaximumcoderate 0 85 thethroughputis71 97Mbps TDDUplinkandDownlinkMaximumREs DownlinkMaximumThroughput 260 16 assuming0 92coderate 239 34MbpsUplinkMaximumThroughput 50 80Mbpsassuming0 85coderate 43 18Mbps PDSCHRes Mode5 PUSCHRes Mode0 Downlinktransportchannelandphysicalchannelprocessingfordatatransmission 24bitsofCRCCodeblocksizeform40to61441 3turbocoderDifferentpuncturingpatternstocreatedifferentrates Uplinktransportchannelandphysicalchannelprocessingfordatatransmission Afterconcatenation thedataandCQIor andPMIcontrolinformationaremultiplexedtogetherChannelinterleavermapstheadjacentdatasymbolstotheadjacentSC FDMAsymbolsinthetimedomainfirstandtheninthefrequencydomaintransformprecodingreferstodividingtheblockofinputsymbolsMintoM NSCrbsetsthateachsetcorrespondstooneSC FDMAsymbol ChannelCodingandRateMatching Turbocodingbasicrateis1 3InterleaverisQuadraticPermutationPolynomialRateMatching RM algorithmselectsbitsfortransmissionviapuncturingorrepetition SimulationParameters SimulationsaredoneinMATLABUsingCMLlibraryTwodifferentcodeblocksizesareused 6144and40 themaximumandminimum BackgroundLTEGeneralArchitectureThesisObjectiveandMotivationLiteratureReviewLTEPhysicalLayerCharacteristicsPerformanceStudyApproachSimulationResultsandAnalysisSummaryandConclusion SimulationResultsandAnalysis Framesizes 40and6144QPSK 16 QAM 64 QAM SimulationResults cont PDSCHThroughput1 4MHzSISOand20MHZ4x4MIMOQPSK RC 0 7516 QAM RC 0 8