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数字调制解调技术中英文资料外文翻译文献英文文献Technologyofdigitalmodulationanddemodulationplaysaimportantroleindigitalcommunicationsystem,thecombinationofdigitalcommunicationtechnologyandFPGAisacertainlytrend.Withthedevelopmentofsoftwareradio,therequirementfortechnologyofmodulationanddemodulationishigherandhigher.Thispaperstartswithstudyingdigitalmodulationanddemodulationtheoryatfirst,andanalysesbasicprincipleofthreekindsofimportantmodulationanddemodulationway(FSK,MSK,GMSK).TheRohde&SchwarzSME03,SignalGenerator,providesAMmodulationandExternalFSKdigitalmodulationrequiredforthedevelopmentandtestingofdigitalmobileradioreceivers.TheapplicationofPWMindigitalmodulationanddemodulationforanalogcommunicationsignalsinseveralmodulationmodesResearchresultsprovethatthedesignofdigitalIFmodulatoranddemodulatorofSoftwareRadioappeasesthecapabilityandrequirementofSoftwareRadio.Atransfusionspeedmonitorsystemisdesignedbasedoninfraredtechnologywithmodulationanddemodulation.It'sthecombinationofmodulatoranddemodulator.Timesynchronizationthatiskeytechnologyofdigitaldemodulationisccalliedbysoftware.ThepaperprovidesthedesignofhardwareofdigitalIFmodulatoranddemodulatorofSoftwareRadiowhichincludesDigitalSignalProcessor、MicroControlUnitandAD/DAconvertoretc.DigitalDown/UpConverter(DDC/DUC),modulationanddemodulationarediscussedinthedissertationassomeessencialpartsofSDRplatform.TwoWayAutomaticCommunicationSystem(TWACS)isanewvaluablecommunicationtechnologyfordistributionnetworks,whichhasspecialofmodulationanddemodulation.Inthispaper,westudytheOFDMtechnologybasedon802.16a,realizethebasebandmodulationanddemodulationbyusingTMS320C6201,andoptimizethesoftwaremodule.ThepaperintroducestheprincipleofQPSKmodulationanddemodulation,thecircuitarealsoberealizedbasedonFPGA.Withtheimprovementofthetechnology,especiallyinthefieldssuchascomputertechnology,datacodingandcompress,digitalmodulationandVLSI,theworldelectronicinformationindustryenterintothedigitalera.First,thefeaturesoffaxcommunicationandthemodeofmodulationanddemodulationaredescribed.Inautomaticclassificationofdigitalmodulationsignal,computingenvelopevarianceafterdifferencehasimportantmeaningtodistinguishPSKandFSKsignal.Thescienceandtechnologyofspaceflight.TheeffectonmodulationanddemodulationofQPSKviacarrierphasenoisecannotbeignored,anditisdifficulttoanalyze.Digitalmodulationerrorparameters,suchaserrorvectormagnitudeEVM,isimportantintestandmeasurementofinformationsystem.Thispaperintroducesthetechnologyresearchprogressinthemetrologyofdigitalmodulationerrorparameters.First,wepointoutthebasicproblemsexistinginthefield,whichisabouttraceabilityandparameterrangeofcalibration,anddescribetherelevantresearch,suchasthethinkingandtechnologyofthe`RFwaveformmetrology'.Then,wehighlighttheresearchprogressofourteam:1).ThemetrologymethodandsystemfordigitaldemodulationerrorparameterbasedonCWcombination,whichfitsBPSK,QPSK,8PSK,16QAM,64QAMmodulation:thismethodcanachievetraceabilityanderrorsettingabilityinawiderange,whenstandardEvmRmsis1.585%,theexpandeduncertainty(k=2)is0.009%.2).ThemetrologymethodandsystemfordigitaldemodulationerrorparameterbasedonanalogAMorPM.3).ThemetrologymethodandsystemfordigitaldemodulationerrorparameterbasedonIQgainimbalanceandphaseimbalance.4).ThemetrologymethodandsystemfordigitaldemodulationerrorparameterbasedonanalogPMintheaspectofGMSKandFSKmodulation.5).ThemetrologymethodandsystemfordigitaldemodulationerrorparameterbasedonBasebandwaveformdesign.Basedonthesemethods,ourproposalaregivenasfollows:first,establishpublicmetrologystandardfordigitalmodulationerrorparameters;second,developanewtypeofinstrumentvectorsignalanalyzercalibrator.Inthispaper,weproposeanovelmethodofchaoticmodulationbasedonthecombinationofChaoticPulsePositionModulation(CPPM)andChaoticPulseWidthModulation(CPWM).Thiscombinationlooksverypromisingfortheimprovementofinformationprivacyinchaos-baseddigitalcommunications.IntheCPPM+CPWMmethod,eachpulseisachaoticsymbolwhichcarriesbinaryinformationoftwobitscorrespondingtoitspositionandwidth,wherethepositionisdeterminedbytheintervalbetweenrisingedgeofthecurrentpulsecomparedtothepreviousoneandthewidthisdeterminedbythedurationbetweentherisingedgeandthefallingedgeofthesamepulse.Thisofferstheincreaseofbitrate,bandwidthefficiencyandprivacyincomparisonwiththemethodofCPPM.TheschemesofModulationandDemodulation(MoDem)ofCPPM+CPWMareproposed,designedandanalyzedthatbasedontheconventionalschemesofCPPM.ThenumericalsimulationintimedomainofthesystemofCPPM+CPWMMoDemisimplementedinMatlab/Simulink.Itgivesasummaryoftheoreticalandpracticalstudiesonthepropertiesofpulse-phasemodulation,developedmainlyin1943.Thepropertiesofpulse-phasemodulationarestudiedbymeansofFouriertransformations.Althoughsomeapproximationsareintroduced,thecalculationsleadtothefollowingdefiniteconclusions:(1)Pulse-phasemodulationintroducesnoamplitudedistortionexceptatsub-multiplesoftherecurrentfrequency.(2)Theharmonicdistortion,ifany,isnegligibleandthismethodofmodulationcanbeusedforhigh-qualitybroadcasting.(3)Pulse-phasemodulationissubjecttoaspecialtypeofdistorti