AMC+Edge英文基礎(chǔ)知識(shí)

1AdaptiveModulationandCodingDec.3,2013Basicprinciples,TechniquesandApplicationsOutlineIntroductionofAdaptiveModulationandCodingAdaptiveTransmissionSystemAdaptiveTechniquesApplicationofAdaptiveModulationandCoding2OutlineIntroductionofAdaptiveModulationandCodingAdaptiveTransmissionSystemAdaptiveTechniquesApplicationofAdaptiveModulationandCoding3IntroductionofAdaptiveModulationandCodingAdaptiveModulationandCoding(AMC):ChangemodulationandcodingrelativetotheChannelStateInformation(CSI)Parameterstoadapt:ConstellationsizeTransmitpowerInstantaneousBERSymboltimeCodingrate/schemeOptimizationcriterion:MaximizethroughputMinimizeaveragepowerMinimizeaverageBER4MainApplicationsofAMCHighSpeedDownlinkPacketAccess(HSDPA)WirelessLocalAreaNetworks(WLAN)WorldwideInteroperabilityforMicrowaveAccess(WiMax,802.16)3GPPLongTermEvolution(LTE,3.9G)5OutlineIntroductionofAdaptiveModulationandCodingAdaptiveTransmissionSystemAdaptiveTechniquesApplicationofAdaptiveModulationandCoding6AdaptiveTransmissionSystem7SystemmodelOutlineIntroductionofAdaptivemodulationandcodingAdaptiveTransmissionSystemAdaptiveTechniquesApplicationofAdaptivemodulationandcoding8AdaptiveTechniquesRateControlFixingsymbolrate，usingmultiplemodulationschemesorconstellationsizesFairlyeasy,usedincurrentsystems,suchasGSM,IS-136EDGEor802.11a,et.al.Fixingthemodulation,changingthesymbolrateVaryingsignalbandwidthisimpracticalandcomplicatesbandwidthsharing.PowerControlAdaptingthetransmitpoweraloneisgenerallyusedtocompensateforSNRvariationduetofading.Tomaintainafixedbiterrorprobability,oraconstantreceivedSNR.ThepoweradaptationthusinvertsthechannelfadingsothatthechannelappearsasanAWGNchanneltothemodulatoranddemodulator.9AdaptiveTechniquesErrorControlAdapttheinstantaneousBERsubjecttoanaverageBERconstraint.Notanadaptivetechnique,sincethetransmitterdoesnotadapttoSNR.Errorprobabilityistypicallyadaptedalongwithsomeotherformofadaptionsuchasconstellationsizeormodulationtype.CodingControlInadaptivecodingdifferentchannelcodesareusedtoprovidedifferentamountsofcodinggaintothetransmittedbits.Adaptivecodingcanbeimplementedbymultiplexingtogethercodeswithdifferenterrorcorrectioncapabilities.Analternativetechniquetocodemultiplexingisrate-compatiblepuncturedconvolutional(RCPC)codes.10AdaptiveTechniquesHybridtechniquesAdaptmultipleparametersofthetransmissionscheme,includingrate,power,coding,andinstantaneouserrorprobability.Jointoptimizationofthedifferenttechniquesisusedtomeetagivenperformancerequirement.Rateadaptionisoftencombinedwithpoweradaptationtomaximizespectralefficiency.11OutlineIntroductionofAdaptivemodulationandcodingAdaptiveTransmissionSystemAdaptiveTechniquesApplicationofAdaptiveModulationandCodingAMCformulti-userEDGE12ApplicationofAMC13AMCformulti-userDownlinktransmissionformatisadaptedtodifferentSNRUserswithhighSNR:useMQAM(largeM)+highcoderatesUserswithlowSNR:useBPSK+lowcoderatesDifferentusergetadifferentrateHigh-speedsharedChannelChannelquality

(CQI,Ack/Nack,TPC)ADCformulti-user14ADCformulti-user15AMCformulti-userLowerdataratesareachievedbyusingasmallconstellation–suchasQPSK–andlowrateerrorcorrectingcodessuchasrate1/2convolutionalorturbocodes.Thehigherdataratesareachievedwithlargeconstellations–suchas64QAM–andlessrobusterrorcorrectingcodes,forexamplerate3/4convolutional,turbo,orLDPCcodes.ADCformulti-user16AMCvsShannonLimitOptionallyturbo-codesorLDPCcodescanbeusedinsteadofsimpleblock/convolutionalcodesintheseschemesOutlineIntroductionofAdaptivemodulationandcodingAdaptiveTransmissionSystemAdaptiveTechniquesApplicationofAdaptivemodulationandcodingAMCformulti-userEDGE17IntroductionofEDGEEDGE=EnhancedDataratesforGSM(orGlobal)EvolutionEDGE包括EGPRS和ECSDEGPRS是對(duì)GPRS的增強(qiáng)，對(duì)系統(tǒng)的影響主要包括：在RF層采用了8PSK調(diào)制方式，極大提高了單信道的速率對(duì)鏈路層RLC/MAC做了修改，并且定義了更完善和鏈路控制算法18KeytechniquesofEDGE8-PSK調(diào)制解調(diào)多種編碼方式（MCS1~9)鏈路質(zhì)量控制（LQC）鏈路自適應(yīng)（LA）遞增冗余重傳（IR）19GMSKand8PSK

Modulation20與GMSK相同的符號(hào)率，但比特率可提高三倍符號(hào)率：

270.833ksymb/s時(shí)隙比特率：

GMSK：0—22.8kbit/s 8PSK：0—69.6kbit/s

GPRSEDGEModulationGMSK8-PSK/GMSKSymbolrate270ksym/s270ksym/sModulationbitrate270kb/s810kb/sRadiodataratepertimeslot22.8kb/s69.6kb/sMaxuserdataratepertimeslot20kb/s59.2kb/sMaxuserdatarate

(8timeslots)160kb/s473.6kb/sGPRS與EDGE信道編碼21鏈路質(zhì)量控制（LQC）所謂鏈路質(zhì)量控制，就是指在數(shù)據(jù)傳輸過程中通過改變調(diào)制方式和編碼方式，動(dòng)態(tài)地適應(yīng)無線傳輸環(huán)境，以達(dá)到提高鏈路質(zhì)量的方法。EDGE采用了一套精心設(shè)計(jì)的、高效的鏈路質(zhì)量控制算法，定義二種鏈路質(zhì)量控制模式，鏈路適配LA（linkadaption）和增量冗余IR（IncrementalRedundancy）。LQC特點(diǎn)估算鏈路質(zhì)量選擇MCS分割LinkQualityControl

(LQC)22

LA

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