软件无线电快速mimo-ofdm（多输入多输出正交频分复用）系统的模型设计 外文文献 翻译

外文文献原文RAPIDMIMOOFDMSOFTWAREDEFINEDRADIOSYSTEMPROTOTYPINGAMITGUPTA,ANTONIOFORENZA,ANDROBERTWHEATHJRWIRELESSNETWORKINGANDCOMMUNICATIONSGROUPDEPARTMENTOFELECTRICALANDCOMPUTERENGINEERING,THEUNIVERSITYOFTEXASATAUSTIN1UNIVERSITYSTATIONC0803,AUSTIN,TX787120240USAPHONFAGUPTA,FORENZA,RHEATHECEUTEXASEDUABSTRACTMULTIPLEINPUTMULTIPLEOUTPUTMIMOISANATTRACTIVETECHNOLOGYFORFUTUREWIRELESSSYSTEMSMIMOCOMMUNICATION,ENABLEDBYTHEUSEOFMULTIPLETRANSMITANDMULTIPLERECEIVEANTENNAS,ISKNOWNFORITSHIGHSPECTRALEFFICIENCYASWELLASITSROBUSTNESSAGAINSTFADINGANDINTERFERENCECOMBININGMIMOWITHORTHOGONALFREQUENCYDIVISIONMULTIPLEXINGOFDM,ITISPOSSIBLETOSIGNIFICANTLYREDUCERECEIVERCOMPLEXITYASOFDMGREATLYSIMPLIFIESEQUALIZATIONATTHERECEIVERMIMOOFDMISCURRENTLYBEINGCONSIDEREDFORANUMBEROFDEVELOPINGWIRELESSSTANDARDSCONSEQUENTLY,THESTUDYOFMIMOOFDMINREALISTICENVIRONMENTSISOFGREATIMPORTANCETHISPAPERDESCRIBESANAPPROACHFORPROTOTYPINGAMIMOOFDMSYSTEMUSINGAFLEXIBLESOFTWAREDEFINEDRADIOSDRSYSTEMARCHITECTUREINCONJUNCTIONWITHCOMMERCIALLYAVAILABLEHARDWAREANEMPHASISONSOFTWAREPERMITSAFOCUSONALGORITHMANDSYSTEMDESIGNISSUESRATHERTHANIMPLEMENTATIONANDHARDWARECONFIGURATIONTHEPENALTYOFTHISFLEXIBILITY,HOWEVER,ISTHATTHEEASEOFUSECOMESATTHEEXPENSEOFOVERALLTHROUGHPUTTOILLUSTRATETHEBENEFITSOFTHEPROPOSEDARCHITECTURE,APPLICATIONSTOMIMOOFDMSYSTEMPROTOTYPINGANDPRELIMINARYMIMOCHANNELMEASUREMENTSAREPRESENTEDADETAILEDDESCRIPTIONOFTHEHARDWAREISPROVIDEDALONGWITHDOWNLOADABLESOFTWARETOREPRODUCETHESYSTEMIINTRODUCTIONMULTIPLEINPUTMULTIPLEOUTPUTMIMOWIRELESSSYSTEMSUSEMULTIPLETRANSMITANDMULTIPLERECEIVEANTENNASTOINCREASECAPACITYANDPROVIDEROBUSTNESSTOFADING1TOOBTAINTHESEBENEFITSINBROADBANDCHANNELSWITHEXTENSIVEFREQUENCYSELECTIVITY,MIMOCOMMUNICATIONLINKSREQUIRECOMPLEXSPACETIMEEQUALIZERSTHECOMPLEXITYOFMIMOSYSTEMSCANBEREDUCED,HOWEVER,THROUGHORTHOGONALFREQUENCYDIVISIONMULTIPLEXINGOFDMOFDMISANATTRACTIVEDIGITALMODULATIONTECHNIQUETHATPERMITSGREATLYSIMPLIFIEDEQUALIZATIONATTHERECEIVERWITHOFDM,THEMODULATEDSIGNALISEFFECTIVELYTRANSMITTEDINPARALLELOVERNORTHOGONALFREQUENCYTONESTHISCONVERTSAWIDEBANDFREQUENCYSELECTIVECHANNELINTONNARROWBANDFLATFADINGCHANNELSCURRENTLYOFDMISUSEDINMANYWIRELESSDIGITALCOMMUNICATIONSYSTEMS,SUCHASTHEIEEE80211A/G2,3STANDARDSFORWIRELESSLOCALAREANETWORKSWLANSMIMOOFDMTECHNOLOGYISINTHEPROCESSOFBEINGSTANDARDIZEDBYTHEIEEETECHNICALGROUP80211N4ANDPROMISESTOBEASTRONGCANDIDATEFORFOURTHGENERATION4GWIRELESSCOMMUNICATIONSYSTEMS5ASTHETHEORYBEHINDMIMOOFDMCOMMUNICATIONCONTINUESTOGROW,ITBECOMESINCREASINGLYIMPORTANTTODEVELOPPROTOTYPESWHICHCANEVALUATETHESETHEORIESINREALWORLDCHANNELCONDITIONSDURINGTHEPASTFEWYEARS,ANUMBEROFMIMOOFDMPROTOTYPESHAVEBEENDEVELOPED612THESEIMPLEMENTATIONSMAKEUSEOFFPGASORDSPS,WHICHREQUIREALARGEAMOUNTOFLOWLEVELPROGRAMMINGANDAFIXEDPOINTIMPLEMENTATIONTHISISTHEPREFERREDSOLUTIONWHENDEVELOPINGHIGHSPEEDIMPLEMENTATIONSHOWEVER,ITHINDERSTHEFLEXIBILITYOFTHEPLATFORMASTHESESYSTEMSARENOTEASILYRECONFIGURABLEASARESULTWHENEXPERIMENTINGWITHMANYDIFFERENTSPACETIMECODINGSCHEMESORRECEIVERDESIGNS,AMOREFLEXIBLESOLUTIONMAYBEPREFERREDINTHISPAPERWEPROPOSEAMIMOOFDMSYSTEMARCHITECTUREBASEDONTHESOFTWAREDEFINEDRADIOSDRPARADIGMTHEADVANTAGEOFTHISAPPROACHLIESINTHEFACTTHATTHEUSERISNOTREQUIREDTOHAVEINDEPTHHARDWAREKNOWLEDGEANDMAYIMPLEMENTANUMBEROFDIFFERENTSCHEMESBYSIMPLYRECONFIGURINGTHESOFTWARETHEPLATFORMUSESNATIONALINSTRUMENTSRADIOFREQUENCYRFHARDWAREINCONJUNCTIONWITHTHELABVIEWGRAPHICALPROGRAMMINGLANGUAGEWITHTHISARCHITECTURE,ITISPOSSIBLETODEFINEANDSIMULATEASYSTEMINAHIGHLEVELPROGRAMMINGLANGUAGEANDTHENSEAMLESSLYAPPLYTHATCODETOWARDSTHEHARDWAREIMPLEMENTATIONTHISGREATLYREDUCESTHETIMEINVOLVEDINSYSTEMPROTOTYPINGCOMPAREDWITH612,OURPROTOTYPINGPLATFORMCANEASILYBEREDUPLICATEDASITCONSISTSOFCOMMERCIALOFFTHESHELFHARDWAREANDPUBLICLYAVAILABLESOFTWAREAUSERWHOPURCHASESTHERFHARDWAREFROMNATIONALINSTRUMENTSANDDOWNLOADSTHEAVAILABLEMIMOSOFTWARETOOLKITALONGWITHTHEPROTOTYPINGCODEDEVELOPEDBYTHEAUTHORSAVAILABLEAT13,14CANREALIZETHESAMERAPIDPROTOTYPINGBENEFITSWHICHWEDISCUSSINTHISPAPERTHEFLEXIBILITYOFTHECURRENTIMPLEMENTATIONOFTHEPROTOTYPEISLIMITEDBYSOMEHARDWARECONSTRAINTS,SUCHASTHEBANDWIDTHOFTHEPCIBUS,WHICHPREVENTSFULLYREALTIMETRANSMISSIONOVERTHEWIRELESSLINK,ANDSOFTWARECONSTRAINTSLIKEOURLACKOFCOMPLETESYNCHRONIZATIONALGORITHMSINTHESOFTWARE,WHICHCAUSESUSTOUSEAWIREDSYNCHRONIZATIONCHANNELTHESPIRITOFTHISCONTRIBUTIONISTOSUMMARIZEOURMETHODANDDESCRIBEOURFIRSTEFFORTSTOWARDSTHEDEVELOPMENTOFACOMPLETEMIMOOFDMPLATFORMDESIGNEDFORSYSTEMVALIDATIONANDFIG1A22MIMOOFDMSPATIALMULTIPLEXINGSYSTEMCHANNELMEASUREMENTSMOREWORKNEEDSTOBEINVESTIGATEDTOOVERCOMETHELIMITATIONSANDEXPANDTHECAPABILITIESOFOURINITIALDESIGNTHISPAPERISORGANIZEDASFOLLOWSSECTIONIIEXPLORESTHESIGNALMODELFORAMIMOOFDMSYSTEMANDOURSPECIFICMIMOOFDMIMPLEMENTATIONSECTIONIIIDISCUSSESTHESPECIFICSOFTHEHARDWAREANDSOFTWAREPLATFORMSECTIONIVSHOWSPRELIMINARYRESULTSFROMOURSYSTEMIMPLEMENTATIONASWELLASCHANNELMEASUREMENTSININDOORENVIRONMENTSSPATIALMULTIPLEXINGOFDMMODULATOROFDMMODULATOROFDMDOMODOFDMDEMODOFDMEQUALIZERREC0MBINEBITSTREAMSIIMIMOOFDMIMPLEMENTATIONINTHISSECTIONWEREVIEWTHEMIMOOFDMSIGNALMODELANDTHENDESCRIBEOURSPECIFICMIMOOFDMSYSTEMIMPLEMENTATIONAMIMOOFDMSIGNALMODELINAMIMOOFDMSYSTEMSEE8ANDTHEREFERENCESTHEREINMIMOSPACETIMECODESARECOMBINEDWITHOFDMMODULATIONATTHETRANSMITTERWHILECOMPLICATEDSPACETIMEFREQUENCYPROCESSINGISEMPLOYEDATTHERECEIVERFORSIMPLICITYOFEXPLANATION,WECONSIDERSPATIALMULTIPLEXINGASILLUSTRATEDINFIG1THOUGHITWILLBEAPPARENTTHATOTHERTRANSMISSIONTECHNIQUESCANBEIMPLEMENTEDINTHEPROPOSEDARCHITECTUREINAMIMOOFDMSYSTEMWITHMTTRANSMITANTENNASANDMRRECEIVEANTENNAS,THESAMPLEDSIGNALATTHERECEIVERAFTERTHEFFTANDREMOVINGTHECYCLICPREFIXOFASPATIALMULTIPLEXINGMIMOSYSTEMFOROFDMSYMBOLPERIODNANDTONEKCANBEEXPRESSEDBYTHEFOLLOWINGEQUATIONASSUMINGPERFECTLINEARITY,TIMING,ANDSYNCHRONIZATION11,NKKNKYHSWTHEEQUALIZATIONINMIMOOFDMSYSTEMSMAYBEENABLEDTHROUGHDIFFERENTPROCEDURESSUCHASZEROFORCINGEQUALIZER,MINIMUMMEANSQUAREDERROREQUALIZER,VBLASTSUCCESSIVECANCELLINGEQUALIZER,SPHEREDECODER,ANDMAXIMUMLIKELIHOODDECODERSEE1FORANOVERVIEWINOURPROTOTYPEWECURRENTLYIMPLEMENTTHEZEROFORCINGEQUALIZERTHEFLEXIBILITYOFTHEPROPOSEDARCHITECTURETHOUGHALLOWSUSTOPROTOTYPEMORESOPHISTICATEDEQUALIZATIONSTRATEGIESBSYSTEMIMPLEMENTATIONANDSPECIFICATIONSTHEFIRSTIMPLEMENTATIONFEATURESSPATIALMULTIPLEXINGWITHTWOTRANSMITANDTWORECEIVEANTENNAS,ASILLUSTRATEDINFIG1OTHERMIMOSCHEMESAREALREADYAVAILABLEINTHELABVIEWMIMOTOOLKIT14,ANDWEAREPLANNINGTOUSETHISTOIMPLEMENTOTHERSPACEFREQUENCYCODESINTHEFUTURETHESPECIFICATIONSOFTHESYSTEMARELISTEDINTABLEIINOURMIMOOFDMIMPLEMENTATION,OFDMWITH64TONESISEMPLOYEDOVERA16MHZBANDWIDTHTHECYCLICPREFIXIS16SAMPLESLONGTHISCORRESPONDSTOANOFDMSYMBOLDURATIONOF5S,WITHAGUARDINTERVALOF1SANDADATAPORTIONOF4SWETRANSMITOUROFDMSYMBOLSIN200MSDATAPACKETSTHIS200MSWASDETERMINEDBYOURHARDWAREASMEMORYCONSTRAINTSATTHERECEIVERPREVENTEDLONGERACQUISITIONPERIODSTHESYSTEMISEQUIPPEDWITHANADJUSTABLECARRIERFREQUENCYWECHOSETORUNOURSYSTEMAT24GHZ,WHICHISTHECARRIERFREQUENCYUSEDFORWLANS2,3VARIOUSMODULATIONSCHEMESAREPOSSIBLEBPSK,QPSK,16QAM,64QAMALONGWITHOPTIONALCONVOLUTIONALCODINGCHANNELESTIMATIONISCARRIEDOUTBYPERIODICALLYTRANSMITTINGANOFDMTRAININGSYMBOLTHEFREQUENCYATWHICHTRAININGSYMBOLSARESENTCANBEPROGRAMMATICALLYCHANGEDINTHESOFTWAREANDDEPENDSONTHEEXPECTEDVARIATIONOFTHECHANNELTHEESTIMATIONATTHERECEIVERISENABLEDBYTHEPILOTSYMBOLS,SENTOUTOVERORTHOGONALTONESACROSSTHETRANSMITANTENNASWETHENUSEALINEARINTERPOLATIONACROSSTHETONESTOESTIMATETHECHANNELSFULLFREQUENCYRESPONSEONCEWEHAVEACHANNELESTIMATE,THEDATAISDEMODULATEDBYAMIMOZEROFORCINGLINEARRECEIVERDUETOSPACELIMITATIONS,INTHISCONTRIBUTIONWEDONOTPROVIDEANALYTICALDETAILSOFTHECHANNELESTIMATIONALGORITHMEMPLOYEDINTHEPROTOTYPETABLEISPECIFICATIONSOFOURMIMOOFDMIMPLEMENTATIONNOOFTRANSMITANTENNAS2NOOFRECEIVEANTENNAS2CARRIERFREQ24GHZBANDWIDTH16MHZNOOFTONES64SUBCARRIERSPACING25KHZOFDMSYMBOLDURATION5USGUARDINTERVALDURATION1USOFDMDATADURATION4USLENGTHOFCYCLICPREFIX16SAMPLESMIMOSCHEMESPATIALMULTIPLEXINGPACKETDURATION200MSFIG2PICTUREOFTHENATIONALINSTRUMENTSRFHARDWAREWEARECURRENTLYAVOIDINGCARRIERSYNCHRONIZATIONISSUESBYDIRECTLYWIRINGTHECLOCKSOFTHETRANSMITTERANDRECEIVERTOGETHERADDITIONALLY,INORDERTOAVOIDTIMINGISSUESWEARESENDINGATRIGGERFROMTHETRANSMITTERTOTHERECEIVERWHENDATATRANSMISSIONBEGINSSOFTWARESYNCHRONIZATIONISUNDERDEVELOPMENTANDWILLBEINCLUDEDINFUTUREWORKASWEAREFOLLOWINGASDRAPPROACHTOPROTOTYPING,THEREAREMANYPARAMETERSOFTHESYSTEMWHICHCANBEADJUSTEDPROGRAMMATICALLYTHEFLEXIBILITYENABLEDBYASDRMIMOOFDMPROTOTYPEBECOMESCLEARINTHEFOLLOWINGSECTIONWHEREWEPRESENTADETAILEDDESCRIPTIONOFTHEPROTOTYPINGPLATFORMIIIPROTOTYPINGPLATFORMAHARDWAREDESCRIPTIONNATIONALINSTRUMENTSRFHARDWAREISTHEFOUNDATIONOFOURPROTOTYPE,ASILLUSTRATEDINFIGURE2THEHARDWARECOMESINTHEPCIEXTENSIONSFORINSTRUMENTATIONPXIFORMFACTORWHICHISSIMILARTOPCIEXCEPTDESIGNEDFORINDUSTRIALAPPLICATIONSEACHPAIROFTRANSMITTERSANDRECEIVERSISHOUSEDINSEPARATEPXICHASSISEACHPXICHASSISISCONNECTEDTOAPCTHROUGHAPCIBRIDGEWHICHCONNECTSTHEPXIHARDWARETOTHEPCIBUSEACHPCISEQUIPPEDWITHDUAL28GHZPROCESSORSAND2GBOFMEMORYTHESPECIFICATIONSOFTHEHARDWAREISLISTEDINTABLEIIANDTHECORRESPONDINGBLOCKDIAGRAMISDEPICTEDINFIGURE3TABLEIIHARDWARESPECIFICATIONS100MILLIONSAMPLESPERSEC16BITRESOLUTIONARBITRARYWAVEFORMGENERATORPXI542143MHZBANDWIDTH250KHZ27GHZCARRIERUPCONVERTERPXI5610TRANSMITTER13DBRANGE64MILLIONSAMPLESPERSEC14BITRESOLUTIONDIGITIZERPXI562030MHZBANDWIDTH9KHZ27GHZCARRIERRECEIVERDOWNCONVERTERPXI560020MHZREALTIMEBANDWIDTHEACHTRANSMITUNITISCALLEDARFSIGNALGENERATORANDITCONSISTSOFTWOPARTSTHEFIRSTISTHEARBITRARYWAVEFORMGENERATORARBTHEARBACTSASTHEDIGITALTOANALOGCONVERTERDACANDITOPERATESATAMAXIMUMOF100MSAMPLES/SECWITHA16BITRESOLUTIONTHEARBHASA256MBBUFFER,ALTHOUGHTHEHARDWAREISENABLEDTOCYCLETHROUGHTHEBUFFERTOPROVIDEFORCONTINUOUSTRANSMISSIONWHENTRANSMITTINGCOMPLEXDATA,THEARBITSELFUPCONVERTSTHESIGNALTOANINTERMEDIATEFREQUENCYIFOF25MHZTHISIFCANBEPROGRAMMATICALLYCHANGEDBEFORETHESIGNALISSENTTOTHERFUPCONVERTERTHEUPCONVERTERCANMODULATEASIGNALUPTOACARRIERFREQUENCYOF27GHZWITHBANDWIDTHSUPTO20MHZANDISCAPABLEOFAMAXIMUMOF13DBMOFPOWERTHEARBHASATRIGGERLINEAVAILABLEFORTIMINGSYNCHRONIZATION,WHILETHEUPCONVERTERHASANINPUTAVAILABLEFORCLOCKSYNCHRONIZATIONTOEXTENDTHEUSABLERANGEOFTHEPROTOTYPEWEUSEDAMINICIRCUITSZQ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ASWEREPLACEDAPPROXIMATELY8METERSAPARTINBETWEENCUBICLESSOTHATTHEREWASNOLINEOFSIGHTPROPAGATIONPATHS,WITHTWOWALLSBETWEENTHETRANSMITTERANDRECEIVERTHETWOTRANSMITANTENNASWERESPACEDFIVEWAVELENGTHSAPARTFROMEACHOTHERAPPROXIMATELY60CENTIMETERSTOREDUCETHESPATIALCORRELATIONACROSSDIFFERENTMIMOCHANNELS17ANDTHEEFFECTOFMUTUALCOUPLING18THETWORECEIVEANTENNASWERESEPARATEDBYTHESAMEDISTANCEWEMEASUREDTHEMIMOCHANNELSOVERTHETIMEANDFREQUENCYDOMAINSANDTHERESULTSARESHOWNINFIGURE6THETEMPORALEVOLUTIONOFTHECHANNELISFLATDUETOTHELOWDOPPLEREFFECTINFIXEDWIRELESSSCENARIOS,WHEREASTHEFLUCTUATIONSINTHEFREQUENCYDOMAINAREDUETOTHEMULTIPLEPROPAGATIONPATHSINFIGURE7WEDISPLAYTHEAVERAGEPOWERDELAYPROFILEPDPOFCHANNELH22WEFOUNDAGOODFITOFTHISPDPWITHWELLKNOWNMODELSANDMEASUREMENTSRESULTSFORINDOORPROPAGATIONENVIRONMENTS12,16,19NOTETHATTHEMODESTSELECTIVITYOFTHECHANNELH22ISDUETOTHESMALLSPREADINTHEDELAYPROFILEVCONCLUSIONSANDFUTUREWORKINTHISPAPER,WEPRESENTEDAMIMOOFDMPROTOTYPINGARCHITECTUREWHICHEMPHASIZESASDRPARADIGMTHEPLATFORMFREESTHEUSERFROMLOWLEVELHARDWAREIMPLEMENTATIONISSUESANDALLOWSMOREINTENSIVESTUDYOFALGORITHMANDSYSTEMDESIGNISSUESWEILLUSTRATEDAPPLICATIONSOFTHISAPPROACHTOSYSTEMIMPLEMENTATIONANDCHANNELMEASUREMENTSINFUTUREWORKWEPLANTOAPPLYTHISTOSTUDYMACPROTOCOLDESIGNSFORMIMOOFDMADHOCNETWORKS22ASWELLASTOMORECOMPREHENSIVELYANALYZEMIMOCHANNELSASIN21ACKNOWLEDGEMENTSTHEAUTHORSWOULDLIKETOTHANKNATIONALINSTRUMENTSFORTHEIRHARDWAREDONATIONASWELLASANDYHINDEATNATIONALINSTRUMENTSFORHISASSISTANCEWITHTHEHARDWAREANDUTAUSTINSTUDENTSBRETTWESTERVELTANDVEYNUNARASIMANFORTHEIRCONTRIBUTIONSTOTHESYSTEMPROTOTYPE（A）BCDFIG6MIMOCHANNELFREQUENCYRESPONSEFORDIFFERENTCHANNELSFIG7POWERDELAYPROFILEPDPOFCHANNELH2,2IN2DAND3DREFERENCES1APAULRAJ,RNABAR,ANDDGORE,INTRODUCTIONTOSPACETIMEWIRELESSCOMMUNICATIONS,CAMBRIDGEUNIVERSITYPRESS,20032“PART11WIRELESSLANMEDIUMACCESSCONTROLMACANDPHYSICALLAYERPHYSPECIFICATIONSHIGHSPEEDPHYSICALLAYERINTHE5GHZBAND,”IEEESTANDARD80211A19993“PART11WIRELESSLANMEDIUMACCESSCONTROLMACANDPHYSICALLAYERPHYSPECIFICATIONSAMENDMENT4FURTHERHIGHERSPEEDPHYSICALLAYEREXTENSIONINTHE24GHZBAND,”IEEESTANDARD80211G20034“IEEE80211NTASKGROUP,”HTTP/GROUPERIEEEORG/GROUPS/802/11/REPORTS/TGNUPDATEHTM5HSAMPATH,STALWAR,JTELLADO,VERCEG,ANDAPAULRAJ,“AFOURTHGENERATIONMIMOOFDMBROADBANDWIRELESSSYSTEMDESIGN,PERFORMANCE,ANDFIELDTRIALRESULTS,”IEEECOMMUNICATIONSMAGAZINE,VOL40,NO9,PP143149,SEPTEMBER20026AADJOUDANIETAL,“PROTOTYPEEXPERIENCEFORMIMOBLASTOVERTHIRDGENERATIONWIRELESSSYSTEM,”IEEEJOURNALONSELECTEDAREASINCOMM,VOL21,NO3,PP440451,APRIL20037PMURPHY,FLOU,ANDPFRANTZ,“AHARDWARETESTBEDFORTHEIMPLEMENTATIONANDEVALUATIONOFMIMOALGORITHMS,”INIEEEINTERNATIONALCONFERENCEONMOBILEANDWIRELESSCOMMUNICATIONSNETWORKS,OCTOBER20038GLSTUBER,JRBARRY,SWMCLAUGHLIN,YLI,MAINGRAM,ANDTGPRATT,“BROADBANDMIMOOFDMWIRELESSCOMMUNICATIONS,”INPROCOFTHEIEEE,FEB2004,VOL92,PP2712949TSUGIYAMA,SKUROSAKI,YASAI,ANDMUMEHIRA,“DEVELOPMENTOFANOVELSDMCOFDMPROTOTYPEFORBROADBANDWIRELESSACCESSSYSTEMS,”INWIRELESSCOMMUNICATIONSANDNETWO