无线电通信平台的实现算法的外文文献

AnalysisandImplementationofaNovelSingleChannelDirectionFindingAlgorithmonaSoftwareDefinedRadioPlatformJohnJosephKeavenyCapter1Aradiodirectionfinding(DF)systemisanantennaarrayandareceiverarrangedinacombinationtodeterminetheazimuthangleofadistantemitter.Basically,allDFsystemsderivetheemitterlocationfromaninitialdeterminationoftheangle-of-arrival(AOA).Radiodirectionfindingtechniqueshaveclassicallybeenbasedonmultiple-antennasystemsemployingmultiplereceivers.ClassictechniquessuchasMUSIC[1][2]andESPRITusesimultaneousphaseinformationfromeachantennatoestimatetheangle-of-arrivalofthesignalofinterest.Inmanyscenarios(e.g.,hand-heldsystems),however,multiplereceiversareimpractical.Thus,singlechanneltechniquesareofinterest,particularlyinmobilescenarios.AlthoughtheamountofexistingresearchforsinglechannelDFisconsiderablylessthanformulti-channeldirectionfinding,singlechanneldirectionfindingtechniqueshavebeenpreviouslyinvestigated.Whenconsideringsinglechanneldirectionfindingsystems,wefindthattherearetwodistincttypesofDFsystems.ThefirsttypeofDFsystemistheamplitude-basedDFsystem.Amplitude-basedsystemsdeterminethebearingofthesignal(ortheAOA)byanalyzingtheamplitudesoftheoutputvoltagesfromeachantennaelement.AmplitudeDFsystemsincludetheWatson-WatttechniqueusinganAdcockantennaarray.ThesecondtypeofDFsystemisthephase-basedDFsystem.Phase-basedsystemsusethreeormoreantennaelementsthatareconfiguredinawaysothattherelativephasesoftheiroutputvoltagesareuniqueforeverywavefrontangle-of-arrival.Phase-basedDFsystemsincludethePseudo-Dopplertechniquewithacommutativeswitchbasedantennaarray.Sincebothoftheabovetechniquesareprimarilyanalogtechniquesandhavebeenanalyzedinpreviouswork,wewillinvestigateanewsinglechanneldirectionfindingtechniquethattakesspecificadvantageofdigitalcapabilities.Specifically,weproposeaphase-basedmethodthatusesabankofPhase-LockedLoops(PLLs)incombinationwithaneight-elementcirculararray.OurmethodissimilartothePseudo-Dopplermethodinthatitsamplesantennasinacirculararrayusingacommutativeswitch.IntheproposedapproachthesampleddataisfedtoabankofPLLswhichtracksthephaseoneachelement.TheparallelPLLsareimplementedinsoftwareandtheiroutputsarefedtoasignalprocessingblockthatestimatestheAOA.ThisthesispresentsthedetailsofthenewalgorithmandcomparesitsperformancetoexistingsinglechannelDFtechniquessuchastheWatson-WattandthePseudo-Dopplertechniques.WealsodescribetheimplementationofthealgorithmonaDRSSignalSolutionsIncorporated(DRS-SS),WJ-8629ASoftwareDefinableReceiverwithSunrise.Technologyandpresentmeasuredperformanceresults.Simulationsonasignalwith10dBSNRhaveshownthattheWatson-WattalgorithmandthePseudo-Doppleralgorithmhaveanaccuracythatisworsethantheproposedtechniquebyapproximatelyanorderofmagnitude.Thealgorithmwasimplementedonasingle-channelDSP-basedsoftwareradiowithahomemadeeight-elementcircularantennaarray.TheWJ-8629AsoftwaredefinedradioreceiverwasprovidedbyDRS-SSinordertoimplementouralgorithm.TheimplementationwastestedusingaCWsignalat~1.57068GHzinalowmultipathlaboratoryenvironmentandoutdoors.TheperformanceoftheprototypeiscomparedtothedataprovidedbythesimulationsinMatlab.ImplementationresultsfocusonCWmeasurementsinarelativelybenignlaboratoryenvironmentforproof-of-concepttesting.Thisdocumentwillshowthatthebasicversionofthealgorithmcanresultinasignificantcomputationalburden,thusweinvestigatealow-complexityapproachanddemonstrateitsperformance.Itwillbeshownthatasignificantcomputationalreductioncanbeachievedwithminimalperformancepenalty.1.1SoftwareIntroductionDuringourresearch,allofthesingle-channeldirectionfindingsimulationswereperformedusingtheMATLAB6.1software.Afterthesimulationswerecompleted,theMATLABcodewasthenportedtohardwareforimplementationusingtheCprogramminglanguage.TheinitialCprogramswerewrittenandtestedtoprovethatthealgorithmscouldbeimplementedontheTIbasedsoftwareradio.AftertheCprogramsweretestedandcomparedtotheirMatlabcounterparts,theywerethenoptimizedfortheTexasInstrumentsTMS320C67xDigitalSignalProcessor.1.2HardwareIntroduction1.2.1DRSSignalSolutions,IncorporatedWJ-8629ASoftwareDefinableReceiverwithSunriseTM.TechnologyTheimplementationwasperformedonaTexasInstrumentsDSP-basedWJ-8629AsoftwaredefinedradioprovidedbyDRS-SS.Ithasafrequencyrangefrom20to2700MHzwith10-Hzresolution,receiverfilteringwith22filterslots(200Hzto1.23MHz),and5reservedslotsforuser-downloadablecustomfiltersThemainprocessingunitistheTexasInstrumentsTMS320C6701DSPprocessorwithamaximumcomputationalrateofnearly1GFlops.TheradioallowsonetodevelopalgorithmsforcertainsignalprocessingmodulesintheCprogramminglanguageortheTMS320C67xassemblylanguage.Otherdetailsoftheradioarenotlistedhereduetotheirproprietarynature.Throughoutthisthesiswewillincludeonlythosedetailsnecessaryforproperunderstandingoftheimplementation.1.2.2MPRGAntennaArrayTheantennabaselineisthegeometriclineofinterconnectionbetweenantennaelements.Antennaapertureisdefinedastheplanesurfaceareaneartheantennathroughwhichmostoftheradiationflows.Thespacingbetweenantennaelementsusuallydeterminestheapertureofanarray,andsinceweare