數字信號處理（英文）知到智慧樹期末考試答案題庫2025年西北工業大學x[n]*δ[n-k]=?（）

答案:x[n-k]x[n]*(h1[n]*h2[n])=(x[n]*h1[n])*h2[n].（）

答案:對Whichofthefollowingstatementistrue?（）

答案:AstablesystemhasitsFouriertransformWhichofthefollowingshouldhaveduality?（）

答案:DFS；DFTWhichofthefollowingrelationistrueifthesignalx[n]isreal?（）

答案:X*(ω)=X(-ω)Whichofthefollowingis/aretheadvantageofIIRfilter?（）

答案:Prototypefilters；Closed-formdesignWhichofthefollowingis/arecorrespondingtoalowfrequency?（）

答案:Whichofthefollowingis/arecorrespondingtoalowfrequency?（）WhichofthefollowingistrueregardingthenumberofcomputationsrequirestocomputeanN-pointDFT?（）

答案:WhichofthefollowingistrueregardingthenumberofcomputationsrequirestocomputeanN-pointDFT?（）WhichofthefollowingisthedisadvantageofIIRfilter?（）

答案:NonlinearphaseWhichofthefollowingisthedifferenceequationofaspecialcaseofFIRsystem?（）

答案:WhichofthefollowingisthedifferenceequationofaspecialcaseofFIRsystem?（）WhichofthefollowingisthecorrectformulaforDTFT?（）

答案:WhichofthefollowingisthecorrectformulaforDTFT?（）WhichofthefollowingistheadvantageofHanningwindowoverrectangularwindow?（）

答案:SmallersidelobesWhichofthefollowingistheadvantageofFIRfilter?（）

答案:LinearphaseWhichofthefollowingisdonetoconvertacontinuoustimesignalintodiscretetimesignal?（）

答案:SamplingWhichofthefollowingconditionsmadedigitalsignalprocessingmoreadvantageousoveranalogsignalprocessing?（）

答案:Flexibility；Accuracy；Storage；RobustnessWhichofthefollowingconditionistobesatisfiedfortheFouriertransformofasequencetobeequalastheZ-transformofthesamesequence?（）

答案:|z|=1WhichofthefollowingblockisnotrequiredindigitalprocessingofaRADARsignal?（）

答案:D/AconverterWhatistheROCofz-transformofantwosidedinfinitesequence?（）

答案:r2<|z|WhatistheROCofthesystemfunctionH(z)ifthediscretetimeLTIsystemisBIBOstable?（）

答案:ContainunitcircleWhatistheROCofthesignalx[n]=δ[n-k],k>0?（）

答案:Entirez-plane,exceptatz=0WhatistheorderofoutputsequenceforDIF-FFT?（）

答案:Bit-reversedWhatistheorderofinputsequenceforDIT-FFT?（）

答案:Bit-reversedWhatistheorderofcomputationalcomplexityfor16-pointDFTinit'sFFTcomputation?（）

答案:64Whatistheorderofcomputationalcomplexityfor16-pointDFTinit'sdirectcomputation?（）

答案:256WhatisthehighestfrequencythatiscontainedinthesampledsignalwiththesamplingfrequencyofFs?（）

答案:Fs/2WhatistheDFTofthefourpointsequencex[n]={0,1,2,3}?（）

答案:{6,-2+2j,-2,-2-2j}WhatarethevaluesofzforwhichthevalueofX(z)=∞?（）

答案:PolesWhatarethemajortwotypesofFFTcomputation?（）

答案:DIT；DIFWhatarethemaincharacteristicsofanti-aliasingfilter?（）

答案:Ensuresthatbandwidthofsignaltobesampledislimitedtofrequencyrange；Tolimittheadditivenoisespectrumandotherinterference,whichcorruptsthesignal；LowpassfilteringWhataretheadvantagesofdigitalsignalprocessing:（）

答案:Flexibleandprogrammable；Reliableandaccurate；EasytoimplementbyVLSI；PopularityofdigitaldevicesWecannotguaranteeadigitalfilterwithlinearphaseinIIRfilterdesignusingbilineartransformorimpulseinvariance.（）

答案:對WecanguaranteeadigitalfilterwithlinearphaseinFIRfilterdesignthroughwindowing.（）

答案:對TodesignanIIRhigh-passfilter,bilineartransformshouldbeusedinsteadofimpulseinvariance.（）

答案:對Todesignacausallow-passFIRfilterwithgeneralizedlinear-phase,whichofthefollowingcanbechosen:（）

答案:Todesignacausallow-passFIRfilterwithgeneralizedlinear-phase,whichofthefollowingcanbechosen:（）Todesignacausalband-stopFIRfilterwithgeneralizedlinear-phase,whichofthefollowingcanbechosen:（）

答案:Todesignacausalband-stopFIRfilterwithgeneralizedlinear-phase,whichofthefollowingcanbechosen:（）Todesignaband-stopfilter,youwouldchoose:（）

答案:IIRfilterdesignusingbilineartransform.；FIRfilterdesignthroughwindowingwiththewindowsizeanevennumber.TherearetwosignalswithlengthN1andN2,respectively.IfwewishtofindouttheirlinearconvolutionthroughM-pointDFT,whichofthefollowingMcanbeapplied?（）

答案:N1+N2Thez-TransformX(z)ofadiscretetimesignalx[n]isdefinedas（）

答案:Thez-TransformX(z)ofadiscretetimesignalx[n]isdefinedas（）Thesystemdescribedbytheinput-outputequationsy[n]=x(-n)isacausalsystem.（）

答案:錯Thesystemdescribedbytheequationy[n]=ay[n-1]+bx[n]isanIIRsystem.（）

答案:對TheSNRincreasesabout6dBforeachbitaddedforquantization.（）

答案:對TheROCofz-transformofanysignalcannotcontainpoles.（）

答案:對Themultiplicationofthewindowfunctionw[n]withh[n]isequivalenttothemultiplicationoftheirfrequencyresponses.（）

答案:錯Thelargerthequantizationstepis,thehigherthesignal-to-noiseratiowillbe.（）

答案:錯TheimpulseresponseofaLTIsystemish[n]={1,1,1}.Whatistheresponseofthesignaltotheinputx[n]={1,2,3}?（）

答案:{1,3,6,5,3}TheFouriertransformofanaperiodicsequenceis（）

答案:Continuous；PeriodicTheeigenfunctionofanLTIsystemisthe（）

答案:complexexponentialsequenceTheDFSforthesignalx[n]=cos（n）exists.（）

答案:錯SupposewehaveanLTIsystem,anditsinputisanimpulsesequence.Whatarethenamefortheoutputanditsz-transform?（）

答案:impulseresponseandsystemfunctionRegardingIIRfilterdesign,whichofthefollowingprototypefilterwillgenerallyresultinthelowestorder（）

答案:EllipticfilterRegardingIIRfilterdesign,whichofthefollowingprototypefilterwillgenerallyresultinthehighestorder（）

答案:ButterworthfilterRegardingIIRfilterdesign,whichofthefollowingprototypefiltershouldbechosenifthereisanrequirementofmonotonicinthestopband?（）

答案:Butterworthfilter；ChebyshevIfilterRegardingIIRfilterdesign,whichofthefollowingprototypefiltershouldbechosenifthereisanrequirementofmonotonicinthepassband?（）

答案:Butterworthfilter；ChebyshevIIfilterRegardingIIRfilterdesign,whichofthefollowingprototypefiltershouldbechosenifthereisanrequirementofmonotonicinboththepassbandandstopband?（）

答案:ButterworthfilterPrerequisitesofthiscourseinclude:（）

答案:Calculus；ComplexVariables；SignalsandSystemsInIIRFilterdesignbytheBilinearTransformation,theBilinearTransformationisamappingfrom（）

答案:S-planetoZ-planeInC/Dconverter,theinputsignaliscontinuousanditwillbesampled.Astheresult,theoutputsignalisdigital.（）

答案:錯InBilinearTransformation,aliasingoffrequencycomponentsisbeenavoided.（）

答案:對Inapracticalsystem,thereisananti-aliasingfilterbeforeA/Dconverter.Suchafiltershouldbe:（）

答案:lowpassIfyoumeasureandrecordyourweighteveryday,thatisadigitalsignal.（）

答案:對Ifx[n]=(0,1,2,3,3,0,0,0)thenx(2n)is?（）

答案:(0,2,3,0,0,0,0,0)Ifx[n]isarealsequenceandX[k]isitsN-pointDFT,thenwhichofthefollowingistrue?（）

答案:AllofthementionedIfwewishtorecoveracontinuoussignalfromitssamples,whatkindoffiltershallweuse,ideally?（）

答案:lowpassIfthereisamodulewhichcanfindouttheoutputofanLTIsystemusingDFT,whichofthefollowingstatementis/aretrue?（）

答案:Theinputsignalofthesystemshouldbefiniteinlength.；TheLTIsystemshouldbeFIR.Ifthesignaltobeanalyzedisananalogsignal,wewouldpassitthroughananti-aliasingfilterwithBasthebandwidthofthefilteredsignalandthenthesignalissampledatarate（）

答案:Fs≥2BIfthesequenceisoflengthLandtheimpulseresponseofanLTIsystemisoflengthP.Whatwillbethelengthaftertheirconvolution?（）

答案:L+P-1IfanLTIsystemhasanimpulseresponsewithfinitesamplevalues,anditisIIR,itisanunstablesystem.（）

答案:錯IfanLTIsystemhasanimpulseresponsewithfinitesamplevalues,anditisFIR,thenitisastablesystem.（）

答案:對IfallthepolesofH(z)areinsidetheunitcircle,thenthesystemissaidtobe（）

答案:BIBOstableandcausalIfafeedbackloopisobservedinthestructure,thecorrespondingsystemisIIR.（）

答案:錯ForanFIRsystem,it’sROCofz-transformis（）

答案:Theentirez-planeexceptfor0orinfinityForadecimation-in-timeFFTalgorithm,whichofthefollowingistrue?（）

答案:Inputisinbit-reversedorderandoutputisinsequentialorderForadecimation-in-frequencyFFTalgorithm,whichofthefollowingistrue?（）

答案:Inputisinsequentialorderandoutputisinbit-reversedDigitalsignalprocessingissomethingnewanddoesnothavealongandrichhistory.（）

答案:錯DFTis,inessence,periodicastheDFS,sinceitcorrespondstosamplingtheFouriertransform.IndefiningtheDFTrepresentation,wearesimplyrecognizingthatweareinterestedinthevaluesinoneperiod.（）

答案:對DFSisperiodic.（）

答案:對Convolutionsumisusefulforcomputationoftheoutputifthesystemis（）。

答案:linear&timeInvariantConsideringFIRfilterdesignusingwindowingmethod.Thewidthofthetransitionbandisapproximatelythesameas:（）

答案:mainlobewidthCausallinear-phaseFIRsystemshavethefollowingcharacteristics:（）

答案:Causallinear-phaseFIRsystemshavethefollowingcharacteristics:（）AnLTIsystemissaidtobecausalifandonlyif?（）

答案:ImpulseresponseiszerofornegativevaluesofnAspeechsignalaswellasadigitalimagearetypicallyin1D.（）

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