1外文文獻(xiàn)ADAQCARDBASEDMIXEDSIGNALVIRTUALOSCMOSCOPEABSTRACTCOMPLEXSIGNALSFINDMANYAPPLICATIONSINSONAR,RADAR，ECHOLOCATIONSYSTEMSANDFORSTUDYINGTHERESONANTFREQUENCIESDIGITALSTORAGEOSCILLOSCOPCSDSOISUSEDTHESEDAYSFORACQUISITIONANDDISPLAYOFROUTINESIGNALSTHISINSTRUMENT,FOUNDINEVERYMEASUREMENTLABORATORY,THOUGHPOTENTINDISPLAYINGSIMPLEPERIODICWAVEFORMSLIKESINUSOIDSFAILSWHENFREQUENCYVARYINGTIMESIGNALSAREAPPLIED,THISPROBLEMSURFACESBECAUSETHEUNDERLYINGTECHNIQUEOFOSCILLOSCOPEUSEDTOTRIGGERTHEWAVEFORMDOESNOTACQUIESCEWITHCOMPLEXSIGNALSLIKECHIRPREADYSOLUTIONTOTHISPROBLEMISTHEMIXEDSIGNALOSCILLOSCOPETHISISACOSTLYSOLUTIONANDSMALLLABORATORIESCANNOTAFFORDTOHAVETHECOSTLYINSTRUMENTSINTHISPAPER,ACOSTEFFECTIVEDAQCARDBASEDMIXEDSIGNALVIRTUAL0SCILLOSCOPEISPROPOSEDTOSTUDYTHECOMPLEXSIGNALSANINTELLIGENTTECHNIQUE,WEIGHTEDHAMMINGDISTANCEWHDALGORITHMWASUSEDTOACCURATELYTRIGGERTHECOMPLEXWAVEFORMSALSOFORFREQUENCYDOMAINANALYSIS,JOINTTIMEFREQUENCYANALYSISJTFATECHNIQUESWEREUSEDALABVLEWTMBASEDVIRTUALINSTRUMENTWASDESIGNEDANDDEVELOPEDWITHACAPABILITYTOACQUIRE,DISPLAYANDANALYZETHETRIGGEREDSIGNALTHEINTEGRATEDPROGRAMMINGLANGUAGELABVIEWTMWASCHOSENASITOFFERSMANYSIMPLEREADYTOUSEFUNCTIONSINAWAYTHEPROPOSALOFFERSACOSTEFFECTIVE,FASTANDFLEXIBLESOLUTIONTOTREATTHECOMPLEXSIGNALSTHENEEDTOCREATESUCHSOLUTIONSISTHECONSEQUENCEOFCOSTLYHARDWARESYSTEMSTHEDEFICIENCYOFCONVENTIONALHARDWARESCHEMEFORTHEVIRTUALOSCILLOSCOPEFORCOMPLEXSIGNALSWITHSOMEREALTIMEEXPERIMENTALRESULTSAREPRESENTEDINTHISWORKKEVYWORDSVIRTUALINSTRUMENTATION,CHIRPSIGNAL,DATAACQUISITION,TRIGGERING,COMPLEXSIGNALS,JTFA1INTRODUCTIONFORTHELASTTWODECADESTHEREHASBEENATREMENDOUSPROGRESSINCOMPUTERTECHNOLOGYMEASUREMENTDOMAINISNOLONGERLEFTUNAFFECTEDTHEWAYMEASUREMENTSAREBEINGDONEISTOTALLYREVOLUTIONIZEDCOMPUTERBASEDMEASUREMENTORSAYVIRTUALINSTRUMENTATIONISGRADUALLYREPLACINGTHECOSTLYBENCH2TOPINSTRUMENTATIONASITOFFERSFLEXIBLE,FASTANDCOSTEFFECTIVESOLUTIONSVARIOUSCLASSICALINSTRUMENTATIONSYSTEMSNAMELYOSCILLOSCOPE,MULTIMETERSANDSPECTRUMANALYZERSECTAREALMOSTPHASEDOUTBYTHEIRCOUNTERPARTVIRTUALINSTRUMENTATIONOURRESEARCHEXTENDSTHETRENDANDDEMONSTRATESTHEDEVELOPMENOFTHECOMPUTERBASEDMIXEDSIGNALDIGITALOSCILLOSCOPECONVENTIONALSIGNALSSUCHASTHESINUSOIDSHAVEACONSTANTFREQUENCYANDTHEAMPLITEDEONLYVARIESWITHTIMETHROUGHOUTTHESIGNALDEFINITIONONTHEOTHERHAND,COMPLEXSIGNALSCANBEDEFINEDINTHISCONTEXTASSIGNALSINWHICHALLTHEPARAMETERSVARYFIG1SHOWSATYPICALCOMPLEXSIGNALIELINEARCHIRPVARIATIONOFAMPLITUDEANDFREQUENCYWITHTIMECANEASILYBEUNDERSTOODBYHAVINGALOOKATTHESIGNALTHISREQUIRESAVISUALLYSTABLEDISPLAYOFSIGNALTHECOMPLEXSIGNALOFFERSCHALLENGESFORACQUISITION,DISPLAYANANALYSISEVENTHECONVENTIONALMODERNAGEDSOISNOTCAPABLEOFDISPLAYINGANDANALYZINGCOMPLEXSIGNALSBECAUSETHESEINSTRUMENTSEMPLOYSIMPLETRIGGERINGTECHNIQUELIKELEVELTRIGGERTHECONVENTIONALTECHNNIQUEOFVOLTAGETRIGGERAPPARENTLYFAILSWHENCOMPLEXSIGNALSLIKECHIRPAREANALYZEDONDSOTHISISDUETOTHEVERYFACTTHATTHESEINSTRUMENTSCONSIDERCHIRPASACONVENTIONALSINEWAVEANDTRIGGERFOREACHCYCLEOFTHESINEWAVEINSTEADOFTRIGGERINGFORTHECOMPLETECHIRPCYCLETHISANALYSISOFTHECHIRPSIGNALASSEVERALSINEWAVEFORMSOFDIFFERENTFREQUENCIESLEADSTHEDSOTODISPLAYTHEMASSINUSOIDSINQUICKSUCCESSIONASTHISRAPIDCHANGEOCCUESATAVERYHIGHRATEANDBECAUSEOFHUMANEYENOTREGISTERINGEVENTSOCCURRINGFASTERTHAN1/20THOFASECONDTHEDISPLAYAPPEARSASSEVERALOVERLAPPEDSINEWAVESINTHERECENTWORK1,ANEWTRIGGERINGTECHNIQUEWASPROPOSEDFORTHECOMPLEXSIGNALSBASEDONWHDSUBSEQUENTSECTIONSPRESENTTHESOLUTIONTOTHEPROBLEMFORANALYSISOFTHECOMPLEXSIGNALSINFREQUENCYDOMAINJFFATECHNIQUEISUTILIZEDANDIMPLEMENTED26DSOUSESTHELEVELTRIGGERTODISPLAYTHEWAVEFORMAPPLIEDTOITTHISLEADSTOTRIGGERINTERVALANDTHENUMBEROFSAMPLESFORTHISTRIGGERINTERVALISCOMPUTEDANDTHESENUMBERSOFSAMPLESAREDISPLAYTHEDSOCONSIDERSTHEINTERVALASTHEFUNDAMENTALTIMEPERIODOFTHEWHOLEWAVEFORMANDTHUSTAKESTBATMUCHSAMPLESFROMITSBUFFERANDSTARTSDISPLAYINGITINQUICKSUCCESSIONWITHSIMPLEWAVEFORMLIKEASINEWAVE,LEVELTRIGGERCANACHIEVESTABLEDISPLAYBECAUSETRIGGERINTERVALCONTAINSSAMENUMBEROFCYCLESTHISISSHOWNINFIG2A34NOWFORTHECOMPLEXSIGNALASSHOWNINFIG2B,LEVELTRIGGERINGPRODUCESATRIGGERINTERVALHAVINGVARIABLENUMBEROFCYCLESFORTHESAMENUMBEROFSAMPLES/TIMERESULTINGINAVISUALLYUNSTABLEDISPLAYTHEACTUALTRIGGERINTERVALSHOULDBEONECOMPLETECYCLEFORACHIRPSIGNALASINDICATEDINFIG2CHAVINGDONETHISTHEREPEATEDCHIRPSIGNALFORTHISTIMEDURATIONWILLBEDISPLAYEDWITHOUTANYOVERLAPPINGCOMPONENTSASLONGASTHEENTIRETIMEPERIODISDISPLAYEDTOOBSERVETHESHORTCOMINGSEXPERIMENTALLYINDISPLAYOFCOMPLEXSIGNALSONTHEOSCILLOSCOPETEKTRONIXDUALCHANNELSIGNALGENERATORAFG3022250MS/S,25MHZWASUSEDTOGENERATEACHIRPSIGNALBYCHOOSINGTHESWEEPMODETOSINEWAVEFORMWITHITSFREQUENCYVARYINGLINEARLYWITHRESPECTTOTIMETHISSIGNALWASFEDTOTEKTRONIXTDS20222GS/S,200MHZDUALCHANNELDSOTHEOVERLAPPINGDISPLAYASSHOWNINFIG3WASOBSERVED2INTELLIGENTMETHODOFTRIGGERINGACCURATETRIGGERINGLIESSOLELYONCORRECTIDENTIFICATIONOFTHETIMEPERIODOFWAVEFORMUNDERCONSIDERATIONFORTHISPURPOSE,PATTERNRECOGNITIONSCHEMEWASIMPLEMENTEDTOIDENTIFYTHEPATTERNINTHESIGNAL1ANDTHUSOBTAINTHETIMEPERIODOFONECOMPLETECYCLEOFTHECHIRPFIRST,AFIXEDNUMBEROFSAMPLESNARETAKENASREFERENCEPATTERNTHENTHESIGNALISSHIFTEDBYONESAMPLETOFORMTHETESTPATTERNTHISPATTERNISTHENTESTEDFORITSCLOSENESSTOTHEREFERENCEPATTERNCLOSENESSCANBEDEFINEDASTHEDISTANCEBYWHICHTESTPATTERNISAWAYFROMREFERENCEPATTERNWHDISUSEDASTHEDECISIONFUNCTIONFORCLOSENESSHAMMINGDISTANCEISDEFINEDFORTWOBINARYVECTORSASTHENUMBEROFDIFFERENTBITSAREGIVENTHEIRVECTORSINWHDTHEDIFFERENTBITSAREGIVENTHEIRBINARYWEIGHTINGACCORDINGTOTHEBITPOSITION5ANDTHEIRWEIGHTSACCORDINGTOTHEBITPOSITIONANDTHEIRWEIGHTSARESUMMEDUPWHDOFTWOBINARYNBITNUMBERXANDAISGIVENBYIFXANDAARETWOBINARYVECTORSOFNBITSELEMENT,THENWHDFORTHESETWOVECTORSISCOMPUTEDBYSUMMINGUPTHEELEMENTBYELEMENTWHDANDISGIVENBYFORAVECTOROFDIMENSIONN,THESAMPLESARESHIFTEDNTIMESANDITSCLOSENESSISCOMPUTEDATEACHSHIFTWHENTHESECOMPUTATIONSAREDONE,THEDIFFERENCE洫INTHESIGNALSISFOUNDTOBEMINIMUMIDEALLYZEROWHENNONOISEWHENTHECYCLEREPEATEDITSELFFOLLOWINGARETHEMAJORSTEPSINVOLVEDANDIMPLEMENTEDFORINTELLIGENTTRIGGERMECHANISM1ACQUIRINGTHELONGENOUGHSIGNALUSINGDAQCARDANDTOCONVERTTHEDECIMALVALUESOFSAMPLESINTOBINARYFORM2AFIXEDNUMBERNOFBINARYSAMPLESARESTOREDINARRAYTHESTOREDSAMPLESARESHIFTEDBYAFIXEDCNUMBEROFSAMPLES,N1,INTHISCASE3THEORIGINALSAVEDSAMPLESANDTHESHIFTEDSAMPLESAREXOREDBITBYBITTHERESULTISTHENMULTIPLIEDBYAFACTOROF2,WHEREIREPRESENTTHEPOSITIONOFBIT4THESUMMATIONOFALLTHERESULTINGVALUESGIVESTHEWHDFORNTHSHIFTS65APLOTOFWHDVSNISMADEANDTHEMINIMUMISCALCULATEDBYPEAKDETECTIONMETHODTHEDIFFERENCEBETWEENTWOSUCCESSIVEMINIMAISTHETRIGGERINTERVALINNUMBEROFSAMPLES6THENUMBEROFSAMPLESMULTIPLIEDBYTHESAMPLINGRATERESULTSINTRIGGERINTERVALINSECONDSASATESTCASEWHDALGORITHMISIMPLEMENTEDFORTHEFOLLOWINGTRIANGULARWAVEFORRNINFIG4THEWAVEFORMISSAMPLEDAT8POINTSPEREYCLEEACHSAMPLEDVALUEIS3BITLENGTHTHESTEPBYSTEPIMPLEMENTATIONISGIVENBELOW7WHDWAVEFORRNISPLOTTEDUSINGWHD1,WHD2,WHD8,ANDTHELOCATIONOFTHEMINIMAGIVESTHETRIGGERINGINTERVALFIG5SHOWSTHEWHDWAVEFORMALSOCLEARLYINDICATINGTHETRIGGERINTERVALAT8THSAMPLETHEWHDVIFIG6WASDEVELOPEDFORTHISTASKITTAKESTHEWAVEFORM,WHOSETRIGGERINGINTERVALISTOBEFOUND,ANDTHENOOFSAMPLES,ONWHICHCOMPUTATIONISTOBEDONE,ASINPUTANDOUTPUTSTHESAMPLEATWHICHMINIMAOCCURSALONGWITHTHEVALUEOFMINIMAANDTHEWHDWAVEFORMFORTYPICALCHIRPSIGNALWHDWAVEFORMISOBTAINEDASSHOWNINFIG7THENUMBEROFSAMPLESBETWEENTWOCONSECUTIVEMINIMAISEQUALTOTHENUMBEROFSAMPLESINONECYCLEOFTHEWAVEFORMTHEPRODUCTOFTHENUMBEROFSAMPLESWITHTHESAMPLINGINTERVALISTHETRIGGERINGINTERVALOFTHEINPUTSIGNALTHUS,THEVIRTUALINSTRUMENTCOULDALSODISPLAYCOMPLEXWAVEFORMSWITHCONSIDERABLEAESEFIG7SHOWSTRIGGERINGINTERVALOF5CYCLES3FREQUENCYDOMAINANALYSISFORSIMPLESIGNALSTHEFREQUENCYANALYSISISPERFORMEDBYTRADITIONALTOOLSLIKEFFTFORSUCHSIGNALSTHEFOURIERTRANSFORMWORKSWELLASTHEIRFREQUENCYCOMPONENTSREMAINCONSTANTTHROUGHOUTTHESIGNALEXISTENCEANDHENCETHEREISNONEEDFORTHETIMEFREQUENCYRELATIONSHIPINCASEOFCOMPLEXSIGNALSTHEFREQUENCYVARIESWITHTIMEFFTFAILSTOANALYZETHESESIGNALSASITGIVESINFORMATIONABOUTTHEFREQUENCYANDITSAMPLITUDETIMEINFORMATIONISLOST8INORDERTOOVERCOMETHISDIFFICULTY,THEREAREJTFATOOLSIIKESHORTTIMEFOURIERTRANSFORMSTFTANDWAVELETTRANSFORMTHESEAREIMPLEMENTEDFORTHESIGNALSUNDERCONSIDERATIONTHESTFTISAMODIFIEDFORMOFFOURIERTRANSFORMINTHISTECHNIQUETHESIGNALISRNULTIPLIEDWITHAWINDOWFUNCTIONANDTHEIRPRODUCTSFOURIERTRANSFORM2THEMAINPRINCIPLEBEHINDTHISTECHNIQUEISTHATTHEWINDOWFUNCTIONWBREAKSDOWNTHESIGNALINTOSEGMENTSOFSMALLFINITEDURTIONTHEFREQUENCYCOMPONENTOFTHESIGNALDURINGTHISSEGMENTISASSUMEDTOBECONSTANTBYCOMPUTINGTHEFOURIERTRANSFORMFORTHISSEGMENTTHEFREQUENCYVSAMPLITUDEINFORMATIONISOBTAINEDTHENTHEWINDOWISMOVEDTOANOTHERSEGMENTBYASTEPHAVINGTHESAMEDURATIONASTHEPREVIOUSONEGIVINGTHEFREQUENCYCOMPONENTFORTHATSEGMENTTHUSTHEFREQUENCYFORDIFFERENTTIMEINTERVALSGIVESTIMEFREQUENCYRELATIONSHIPHOWEVER,THEREISADISADVANTAGEWITHTHISTECNIQUETHESIZEOFTHEWINDOWFUNCTIONUSEDISFIXED,THUSSTFTWILLHAVESAMERESOLUTIONFORLOWANDHIGHFREQUENCIESRESOLUTIONISTHECERTAINTYBYWHICHONECANDETERMINETIMEOR9FREQUENCYINFORMATIONITISGENERALLYSEENTHATALARGERWINDOWLEADSTOBETTERFREQUENCYRESOLUTIONANDASMALLWINDOWLEADSTOBETTERTIMERESOLUTIONTHUS,ITDEPENDSUPONTHEUSERWHETHERHEWANTSFREQUENCYORTIMERESOLUTIONEVENIFTHEREISANEEDFORCHANGEOFRESOLUTION,THEUSERHASTODOTHESAMEMANUALLYTOOVERCOMETHERESOLUTIONPROBLERN,AMOREADVANCEDTECHNIQUECALLEDWAVELETTRANSFORMISUSEDTHESEDAYSINTHISTHEWINDOWSIZECANBEALTERED,USINGASCALINGPARAMETERATHEEQUATIONFORWAVELETTRANSFORMISGIVENASWHEREAISTHESCALINGPARAMETER,BISTHETRANSLATIONPARAMETER,XTISTHESIGNALTOBEANALYZEDANDISTHEWAVELETFUNCTIONTHEWAVELETFUNCTIONTISKNOWNASTHEMOTHERWAVELETITSSCALEDANDTIMESHIFTEDVERSIONSAREKNOWNASTHEDAUGHTERWAVELETSTHESEDAUGHTERWAVELETSHAVINGVARYINGSIZEOFFERDIFFERENTFREQUENCYANDTIMERESOLUTIONSATDIFFERENTFREQUENCIESTHESCALEPARAMETERAREPRESENTSTHEFREEQUENCYCOMPONENTINANINVERSERELATIONTHUSTHEVALUCOFSCALEISINVERSELYPROPORTIONALTOFREQUENCYCOMPONENTINITIALLYTHEWAVELETFUNCTIONHASSCALEA1ANDISPLACEDATTHESTARTINGOFTHESIGNALTHEWAVELETTRANSFORMANDTHUSTHEFREQUENCYCOMPONENTOFTHATSEGMENTTHENTHEWAVELETFUNCTIONISMOVEDBYBSTEPSANDTHEWAVELETTRANSFORMISCOMPUTEDFORTHATSEGMENTTHISPROCECDUREISCONTINUEDTILLTHEENDOFTHESIGNALTHUSWAVELETTRANSFORMFORA1ANDALLTHETIMESTEPSTILLTHEENDOFSIGNALGETSCOMPUTEDSIMILARLYTHEWAVELETFUNCTIONISAGAINPLACEDATTHESTARTOFTHESIGNALBUTWITHCHANGEDVALUEOFSCALEATHEPROCEDUREISCONTINUEDTILLTHEWAVELETTRANSFORMFOREACHSCALEANDTIMESTEPCOMBINATIONHASBEENCOMPUTEDITCANBEOBSERVEDTHATTHECOMPUTATIONOFWAVELETTRANSFORMLEADSTOALOTOFREDUNDANCYTOREDUCETHEREDUNDANCY,THESCALEVALUESANDTHETIMESTEPSCANBELINKEDUSINGDYADICSAMPLINGA2“ANDBK2WHERENANDKAREINTEGERSTHISLEADSTOREDUCTIONINREDUNDANCYTHISISCALLEDDISCRETEWAVELETTRANSFORMDWT4IMPLEMENTATION10ADAQCARDBASEDVIRTUALINSTRUMENTWASDESIGNEDANDDEVELOPEDINLABVIEWTMPROGRAMMINGENVIRONMENTTHISVIRTUALINSTRUMENTHASTHECAPABILITYTOGENERATEINTELLIGENTSOFTWARETRIGGERASDESCRIBEDABOVEFORCOMPLEXWAVEFORMSLIKECHIRPTHEMAINDECISIONNSDURINGDESIGNOFTHEVIRTUALINSTRUMENTARECHOOSINGTHEDATAACQUISITIONCARDAND,WHATISEQUALLYIMPORTANT,CHOOSINGTHESETOFFEATURESTHEINSTRUMENTSHOULDOFFERTHECHOICEOFTHEDATAACQUISTIONCARDHASAGREATINFLUENCEONTHEEFFICIENCYOFTHEWHOLEINSTRUMENT7，8PARTICULARDAQCARDSAREDIFFERENTIATEDBYPRICEAND,THESPECIFICATIONITOFFERSALOWCOSTNIPCI6035E,16BIT,200KS/SCARDWASCHOSENTHEHARDWAREWASPROGRAMMEDATMAXIMUMSAMPLINGRATEASEPARATEPROBLEMISDESIGNINGSOFTWARE,WHICH,INTHATCASE,ISTHEMAINPARTOFINSTRUMENTDESIGNPHASETHEMAJORFEATURESOFTHEDEVELOPEDVIRTUALINSTRUMENTARETHECAPABILITYTOACQUIREANDPROCESSSIMPLEANDCOMPLEXWAVEFORMSDUALCHANNELMODETHEINSTRUMENTISCAPABLEOFDISPLAYINGTWOINPUTSSIMULTANEOUSLYANDCANPERFORMSIMPLEMATHOPERATIONSBETWEENTHETWOAUTOSETRUNSTHEWHDCODETORECOMPUTETHETRIGGERINTERVALFORTHENEWSIGNALANDTHUSACHIEVEASTABLEDISPLAYINCASE,THETWOINPUTSDONOTHAVETHESAMEFREQUENCY,THELCMOFTHETRIGGERINTERVALSOFAANDBISFOUNDTOSOTHATINTEGRALNUMBEROFCYCLESOFBOTHTHECHANNELSCANBESHOWNSIMULTANEOUSLYTIMEDOMAINMEASUREMENTSTHESIGNALBEINGDISPLAYEDINTIMEDOMAINAREMEASUREDONVARIOUSPARAMETERSAMPLITUDEPEAKTOPEAKMEANDCRMS1112FIG9THERESULTSOFWAVELETTRANSRORMIMPLEMENTEDINTHEVIRTUALINSTRUMENTCHANNELAANALYZINGSINESIGNALANDCHANNELBANALYZINGACHIRPSIGNALFREQUENCYDOMAINAALYSISTHEPLOTOFMAGNITUDEVSFREQUENCY,PHASEVSFREQUENCYANDTHEFACILITYTOCHOOSETHEWINDOWINGFUNCTIONSTFTBASEDJOINTTIMEFREQUENCYANALYSISJTFATHESPECTROGRAMWITHTHEADDITIONALCHOICESOFTHEPLOTTINGTHEGRAPHWITHSCALEINDECIBELS,WINDOWINGFUNCTIONSANDTHEWINDOWLENGTHFORSTFTANALYSISWAVELETBASEDJOINTTIMEFREQUENCYANALYSISJTFATHESCALOGRAMWHICHPLOTSSCALESVSTIMESTEPS,CHOICEOFTIMEFREQUENCYSAMPLINGPARAMETERSLIKETIMESTEPSANDSCALESANDTHECHOICEOFWAVELETFUNCTIONSFORTHEFREQUENCYDOMAINANALYSIS,DSPTOOLKITAVAILABLEWITHLABVIEWSOFTWARE13WASUTILIZEDSTANDARDFUNCTIONSAREAVAILABLEINTHETOOLKITTHEVIRTUALINSTRUMENTTHUSDEVELOPEDISINTELLIGENTASITTAKESDIFFERENTACTIONSWITHDIFFERENTSIGNALSCONTRARYTOADIGITALSTORAGEOSCILLOSCOPETRIGGERIMPLEMENTEDENABLESUSTOOBTIANTHECORRECTVALUEOFTHETIMEPERIODANDASTABLEDISPLAYANALYSISOFCOMPLEXSIGNALSCANALSOBEPERFORMEDUSINGTHISINSTRUMENTFIG8SHOWSTHEFRONTPANELOFTHEVIRTUALINSTRUMENTSHOWINGTIMEDOMAINMEASUREMENTSFIG9SHOWSTHETIMEFREQUENCYRELATIONSHIPONBOTHTHECHANNELBANALYSESTHECHIRPSIGNALASSEENCLEARLYTHECHIRPSIGNALSHOWSTHEVARYINGFREQUENCYWITHTIME5LIMITATIONSOFDEVELOPEDVIRTUALINSTRUMENTSAMPLESFORFEWCYCLESAREREQUIREDTODETERMINTHETRIGGERINGINTERVALONENEEDTOOPTIMIZETBEAPPROPRIATESAMPLINGRATEANDTHENUMBEROFSAMPLESTOBEPROCESSEDTHEPROCESSINGTIMETAKENBYTHEWHDTECHNIQUEISDIRECTLYPROPORTIONALTOTHENUMBEROFSAMPLESANDHENCETOTHESAMPLINGRATEASTHEHIGHERSAMPLINGRATELEADSTOTHEMORENUMBEROFSAMPLESPERCYCLETHETIMEREQUIREDTOCOMPUTETRIGGERALSODEPENDSUPONTHESPEEDOFTHECOMPUTINGSYSTEMFORLARGEAMOUNTOFDATAIFHIGHSAMPLINGRATESUSFIXED,COMPUTATIONALLYHEAVYWHDALGORITHMANDOTHERFEATURESFORMOREANALYSIS,THEBUTTERMIGHTOVERFLOWLEADINGTOLOSSOFDATAEVERYTIMETHEINPUTWAVEFORMISCHANGEDUSERHASTODORETRIGGERING6CONCLUSIONANDDISCUSSIONSUCCESSFULDEVELOPMENTOFTHEVIRTUALINSTRUMENTWITHTHECAPABILITYOFACQUIRING,DISPLAYINGANDANALYZINGCOMPLEXSIGNALSISDONETHEINSTRUMENTOVERCOMESTHESHORTCOMINGSOFTHEDSOS,FOUNDCOMMONLYINLABORATORIES,INACHIEVINGSTABLEDISPLAYFORCOMPLEXSIGNALSTHEDEVELOPDINSTRUMENTISCOSTEFFECTIVEANDFLEXIBLEINNATUREANDHADTHELARGENUMBEROFFEATURESTOCHOOSEFROMTHECOMPUTERTOWARDSTHEMEASUREMENTSYSTEMSTHEVIDEVELOPEDISEXPECTEDTOGOALONGWAYINTHEINSTRUMENTATIONAREA14基于混合信號(hào)的數(shù)據(jù)采集卡的虛擬示波器摘要復(fù)雜的信號(hào)在聲納、雷達(dá)、回聲定位系統(tǒng)和諧振頻率的研究中有多種應(yīng)用。數(shù)字存儲(chǔ)示波器（DSO）現(xiàn)在被用于獲取和顯示常規(guī)信號(hào)。這臺(tái)儀器普遍用于各個(gè)測(cè)量實(shí)驗(yàn)室，雖然在顯示簡(jiǎn)單周期性波形如正弦波時(shí)有用，但是在變化頻率的信號(hào)運(yùn)用時(shí)，失敗了。這個(gè)問(wèn)題顯露出來(lái)是因?yàn)槭静ㄆ鞯臐撛诩夹g(shù)用于觸發(fā)波形，對(duì)于復(fù)雜信號(hào)像噪聲來(lái)說(shuō)是不允許的。能真正解決這個(gè)問(wèn)題的是混合信號(hào)示波器。這是一種成本高的解決方法，并且小型實(shí)驗(yàn)室承擔(dān)不起昂貴的儀器。在本文中，建議選用成本合G10714的G3534于混合信號(hào)的數(shù)G6466G18331G19610G2357的G15406G6323示波器來(lái)G2010G7524復(fù)雜的信號(hào)。一種G7246能技術(shù)，G7246能G9213G9299G5242G6523G2058器（WHD）G12651法用于G1946G11842觸發(fā)復(fù)雜波形，G1075用G2052了頻G16901G2010G7524和時(shí)頻G2010G7524（JTFA）技術(shù)。G16786G16757了一種G3534于LABVLEW的G15406G6323儀器，發(fā)G4649了獲取、顯示和G2010G7524觸發(fā)信號(hào)的性能。能G1427G6475實(shí)用G2163能G4448G6984的G13546G12255G16833G16340LABVIEW被選為G15406G6323儀器G16786G16757G5191臺(tái)。這是一種G13475G8994高G6940，G5567G17907G9801G8975G2010G7524復(fù)雜的信號(hào)的方法。有G5529G16213建G12447這G7691的解決方G7708是G11840G1226系統(tǒng)G3838昂貴的G13479G7536，這G1075是常規(guī)G11840G1226的不G17287。G991G19766G6563G17860了G15406G6323示波器實(shí)G19481G2010G7524復(fù)雜信號(hào)實(shí)驗(yàn)的G13479G7536。關(guān)鍵字G15406G6323儀器，G16855頻信號(hào)，數(shù)G6466G18331G19610，觸發(fā)，復(fù)雜信號(hào)，JTFA。一緒論在G17819G2447的G1120G2325G5192G18336G16757G12651G7438技術(shù)G20146G17907發(fā)G4649，測(cè)量G20058G3507G1075G9157G2475G5445G2721，測(cè)量方G5347正在發(fā)G10995G13775G3837G16218G3332的變化。G3534于G16757G12651G7438的測(cè)量?jī)x器G6122G13785說(shuō)G15406G6323儀器正在G17892G8505取G1207昂貴的臺(tái)G5347儀器，因?yàn)镚4439G9801G8975、G5567G17907和G13475G8994。各種G1268統(tǒng)儀G15932系統(tǒng)如示波器，G987用G15932和頻G16901G2010G7524儀G12573，G11013于G16757數(shù)G18108G2010G13792被G15406G6323儀器G9132G8772。G6117G1216的研究G4570發(fā)G4649這種G17247G2195，G4649示G3534于G16757G12651G7438的復(fù)雜信號(hào)的數(shù)字示波器的發(fā)G4649G62G28G15G20G19G64。G3常規(guī)信號(hào)G1375如正弦信號(hào)G1867有G5670定的頻率和G19555時(shí)G19400變化的G5145G1552。G2490一方G19766，在這G12699文G12468G18336，復(fù)雜信號(hào)G2499G1209被定G1053為信號(hào)，G4613是G6164有G2454數(shù)G18129變化的信號(hào)。G3282G20顯示了一個(gè)G1868型的復(fù)雜信號(hào)。G315G3G3G11487G11540信號(hào)，很容易G10714解G5145G5242和頻率G19555時(shí)G19400的變化。這需G16213一個(gè)G2499視的、穩(wěn)定的信號(hào)G4649示。G18331G19610和顯示G2010G7524對(duì)復(fù)雜信號(hào)來(lái)說(shuō)是一個(gè)挑戰(zhàn)。即使是G1268統(tǒng)的現(xiàn)G1207DSOG1075不能顯示和G2010G7524復(fù)雜的信號(hào)，因?yàn)檫@些儀器才養(yǎng)的是簡(jiǎn)單的觸發(fā)技術(shù)，比如水G5191觸發(fā)。當(dāng)復(fù)雜信號(hào)像附加G16855頻在示波器上G2010G7524時(shí)，G1268統(tǒng)的電壓觸發(fā)技術(shù)顯然失敗了。這是G11013于這一事實(shí)，這些工G1867把附加G16855頻作為一種G1268統(tǒng)的正弦波，觸發(fā)的是正弦波的每個(gè)周期G13792不是G4448全的附加G16855頻周期。這種附加G16855頻信號(hào)的G2010G7524，G4613像其他不同頻率的正弦波一G7691，導(dǎo)致了DSOG4649示G4439G1216，G4613像連續(xù)的竇狀隙一G7691。G11013于這在一個(gè)非常高的G17907G5242迅G17907變化，人的眼睛根本不能抓住G17907G5242比G20/2G19秒還G5567的事情，G4613像幾個(gè)重疊的正弦波一G7691G4649示。在最近的工作G62G20G64，一個(gè)新的G3534于G7246能G9213G9299G5242G6523G2058器的觸發(fā)技術(shù)被運(yùn)用與復(fù)雜信號(hào)。G19555后的G12468節(jié)G4570呈現(xiàn)解決問(wèn)題的方法。在頻G3507JFFA技術(shù)上對(duì)復(fù)雜信號(hào)的G2010G7524G4570被利用和實(shí)施G6226G64。G3G3G3G3G3DSO使用水G5191觸發(fā)來(lái)來(lái)G4649示波形G4570被應(yīng)用。這G4570導(dǎo)致觸發(fā)G19400隔極G16757G12651和G4649示G7691本數(shù)量。DSO認(rèn)為，作為G6984個(gè)波形的G3534本時(shí)G19400G19400隔，從G4439的緩沖并開(kāi)始G5567G17907連續(xù)顯示中，需G16213多G7691品。有了這G7691一個(gè)簡(jiǎn)單的正弦波波形，水G5191觸發(fā)G2499G1209實(shí)現(xiàn)穩(wěn)定的顯示，因?yàn)橛|發(fā)G19400隔包含的周期相同。這顯示在G32822A。如G32822BG6164示的復(fù)雜信號(hào)，水G5191觸發(fā)產(chǎn)G10995了一個(gè)觸發(fā)G19400隔，這個(gè)觸發(fā)G19400隔，對(duì)G1867有相同數(shù)量的G7691本G6122時(shí)G19400來(lái)說(shuō)有變化的周期數(shù)，這導(dǎo)致了視覺(jué)上的不穩(wěn)定G4649示。實(shí)G19481觸發(fā)G19400隔應(yīng)該是一個(gè)G4448G6984的附加G16855頻信號(hào)周期，如G32822CG6164示。這G7691做之后的重復(fù)附加G16855頻信號(hào)在G4649示出來(lái)的G6984個(gè)時(shí)G19400段G18336G4570持續(xù)顯示出來(lái)，G13792沒(méi)有任何的重疊組G1226G3通G17819示波器來(lái)G4649示復(fù)雜信號(hào)G2499G1209G11487見(jiàn)G4439的缺點(diǎn)，雙通道泰克信號(hào)發(fā)G10995器AFGG33G1922（25G19G3MSG3/G3S的，25兆赫）通G17819選擇關(guān)于時(shí)G19400正弦波的頻率變化與線(xiàn)性G16855頻信號(hào)波形的掃G6563模G5347來(lái)產(chǎn)G10995附加G16855頻信號(hào)。這個(gè)信號(hào)被輸送G2052TEKTRONIG91TDSG32G1922（2G3GSG3/G3S的，2G19G19MG43G93的）雙通道DSO。重疊的顯示如G32823G6164示。G3二觸發(fā)的智能方法16G3G3G1946G11842的觸發(fā)G1177G1177在于對(duì)正在G13783G15397的時(shí)G19400G1881波形的正G11842G16794G2047。為G8504，實(shí)施模G5347G16794G2047G16757G2022來(lái)G11842定信號(hào)的模G5347G62G20G64，從G13792獲G5483一個(gè)G4448G6984附加G16855頻周期時(shí)G19400。G20330G1820，把一個(gè)G3278定的G7691本數(shù)G49作為G2454G13783模G5347。然后，G11013一個(gè)G7691本G17728G12239形成最G3921的模G5347。然后利用G2454G13783模G5347來(lái)測(cè)G16809這種模G5347的G12946G4506G5242。G12946G4506G5242G2499G1209G11013測(cè)G16809模G5347和G2454G13783模G5347的G5058G5334來(lái)定G1053。G3G3G3G3G3G3G7246能G9213G9299G5242G6523G2058器是用來(lái)作為G12946G4506G5242的決定作用。G9035G7138G17329G12175定G1053為G1016個(gè)不同的G10數(shù)位G1120G17839G2058G2533量，G13485出了G17745G1319。在G7246能G9213G9299G5242G6523G2058器中，根G6466不G4439G1216位G13634的同來(lái)G11842定其G1120G17839G2058的G7447重和重量，然后把位G13634和G7447重相加。G1120G17839G2058的G7246能G9213G9299G5242G6523G2058器G1016個(gè)數(shù)X，A是G13485G111610,2NKKKKWHDXAXAG11G20G12G3如G7536G59和AG1016個(gè)G1120G17839G2058G2533量的N位的G1815G13044，G18039G1052這G1016個(gè)G2533量是G5647G13479G7246能G9213G9299G5242G6523G2058器G1815G13044G1815G13044G16757G12651，并G1348510,2ELEMENTN