數(shù)字信號處理（全英文）智慧樹知到課后章節(jié)答案2023年下山東科技大學(xué)

數(shù)字信號處理（全英文）智慧樹知到課后章節(jié)答案2023年下山東科技大學(xué)山東科技大學(xué)

第一章測試

Microcontrollerscannotbeusedindigitalsignalprocessingsystems.（）

答案:

錯

Thedimensionofasignalisdeterminedbythenumberofdependentvariablesinthesignal.（）

答案:

錯

Asignalthatisgeneratedinarandomfashionandcannotbepredictedaheadoftimeiscalledadeterministicsignal.（）

答案:

錯

FIRDFisveryeasytoachieveexactlinearphase,whichisdifficultinanalogsystems.（）

答案:

對

Thetechnologyforsignalprocessingwasalmostexclusivelycontinuous-timeanalogtechnologyuntil（）.

答案:

1960s

Accordingtothedifferentinputsignals,thesystemcanbedividedinto（）.

答案:

DigitalSystem;AnalogSystem;Discrete-timeSystem

第二章測試

Adiscrete-timesignalisrepresentedasasequenceofnumberscalledsamples.（）

答案:

對

Shiftsequencex(n)totherightbymsamples,form>0,resultinginanewsequence（）.

答案:

x(n-m)

Real-ValuedExponentialSequenceanu(n)mustdecayexponentiallyasnincreases.（）

答案:

錯

Asinusoidalsequenceisexpressedby,thusitsperiodis（）.

答案:

12

Frequenciesintheneighborhoodofarecalledlowfrequencies,whereas,frequenciesintheneighborhoodofarecalledhighfrequencies.（）

答案:

錯

Forthefollowingsystem,whichoneislinearsystem?（）

答案:

Theimpulseresponseh(n)istheoutputofaLTIsystemwithzerostatewhentheinputistheunitsamplesequenceδ(n).（）

答案:

對

TocomputetheoutputofLTIsystemdescribedbydifferenceequation,themainmethodsinvolvein（）.

答案:

computationusingMATLAB;classicalsolutionfromtimedomain;solutionfromtransformdomain;recursivesolutionfromtimedomain

Adiscretetimesequencex(n)isdevelopedbyperiodicallysamplingananalogsignalxa(t)atuniformtimeintervals,thusthespectrumofdiscretetimesignalx(n)shouldbeperiodicextensionofthespectrumoftheoriginalanalogsignal.（）

答案:

對

Intheprocessofconvertinganalogsignalstodigitalsignals,thehigherthesamplingfrequencyis,thebettertheprocessingperformanceofthesystemwillbe.（）

答案:

錯

Torecovertheoriginalcontinuoussignalfromthesampledsignalwithoutdistortion,Whichconditionsshouldbesatisfied?（）

Ⅰ.Theoriginalcontinuoussignalshouldbebandlimited；

Ⅱ.Thesamplingrateofsignalsshouldbegreaterthantwicethesignalbandwidth；

Ⅲ.Theideallowpassfiltershouldbeusedtoprocessthesampledsignal.

答案:

Ⅰ、Ⅱ、Ⅲ

第三章測試

Thereisaone-to-onecorrespondencebetweenadiscretetimesignalanditsFouriertransform.（）

答案:

對

Thespectrumofasequencecanbegraphedbymagnitudefrequencycharacteristicsandphasefrequencycharacteristics.（）

答案:

對

TheDTFTofasequencyisaperiodicanddiscretefunctionof.（）

答案:

錯

If，then.（）

答案:

錯

Thebelowfigureisoneofthewaystocomputethelinearconvolutionofx(n)andh(n).WhichFouriertransformpropertydoesitfollow?（）

答案:

Time-DomainConvolutionTheorem

Forthefollowingsequencetypes,whoseFouriertransformisconjugate-symmetric?（）

答案:

areal-valuedsequence

IftheDTFTofasequencyisexpressedas，thenisreferredtoas（）.

答案:

directcurrentcomponent

AsforunderstandingonthedevelopmentandroleofFouriertransform，whicharecorrectforthefollowingstatements？（）

答案:

FFTimprovestheefficiencyofDFTandmeettheneedsofreal-timeprocessinginengineeringpractice.;Allotheroptionsarecorrect.;DFTprovidesamethodofapproximateestimationofsignalspectrumbydigitization.;FTrealizestheconversionofsignalsfromtimedomaintofrequencydomaintheoretically.

ForasequencewithaperiodofN,itsDFSisnotnecessarilyasequencewithaperiodofN.（）

答案:

錯

TheZ-transformtogetherwithitsROCdeterminesasequenceuniquely.（）

答案:

對

Asforunderstandingonthephysicalmeaningoffrequencyresponse，whicharecorrectforthefollowingstatements？（）

答案:

Themagnituderesponseshowsthathowthesystemaffectsamplitudeattenuationofeachfrequencycomponentintheinputsignal.;Thephaseresponseshowsthathowthesystemaffectstimedelayofeachfrequencycomponentintheinputsignal.;Foracomplexexponentialinputsignalwithsinglefrequency,theoutputofanLTIsystemisalsoacomplexexponentialsignalofthesamefrequency.

Forthetransferfunctionofacausalandstablesystem,whicharecorrectforthefollowingstatements？（）

答案:

Ifthepoleislocatedontheunitcircle,thenthevalueofmagnitudefrequencyresponseofthesystemisequaltoinfinity.;Thecloserthepolelocationapproachestotheunitcircle,thegreaterthevalueofmagnitudefrequencyresponseofthesystemwillbe.

第四章測試

Theprocesstoobtainafinite-lengthsequencebytruncatingaverylongsequenceisoftencalledthewindowing.（）

答案:

對

TheN-pointDFTsequenceispreciselythesetoffrequencysamplesoftheFouriertransformofthelength-MsequenceatNequallyspacedfrequencies.（）

答案:

對

Foragivenfinite-lengthsequence,itsperiodicextensioncanbeexpressedas（）.

答案:

;;

Circularconvolutioncanbeobtainedfromtakingtheperiodicextensionforlinearconvolutionfirst,andthentakingtheprincipal-valuerange.（）

答案:

對

Inphysicalapplications,theimplementationoflinearconvolutionusingacircularconvolutionshouldinvolveinFFTalgorithms,whichiscalledfastconvolution.（）

答案:

對

Forthefollowingsequencetypes,whoseDFTareconjugate-symmetric?（）

答案:

unitsamplesequence;sinusoidalsequence;rectangularsequence;unitstepsequence

FortheDTFTofalength-Msequence,WesampleatNequallyspacedpoints.IfNislessthenM,thenthetime-domainaliasingwilloccur.（）

答案:

對

Inthefirststepofanalyzingacontinuous-timesignalusingtheDFT,selectionofthesamplingfrequencyshouldbehigherthantwotimesofthemaximumfrequency.（）

答案:

對

Theimprovementmethodofthefrequencyresolutionistoincreasetheeffectivetime-recordlength.（）

答案:

對

Zero-paddingoperationcanimprovetheabilityofthefrequencyresolution.（）

答案:

錯

Asforanalyzingthespectrumofacontinuous-timesignalusingtheDFT,theshorterthetruncatedsignalis,thesmallerthetruncationerrorwillbe.（）

答案:

錯

Asforanalyzingthespectrumofacontinuous-timesignalusingtheDFT,someparametersaregivenhere,includingthehighestfrequencyfhofsignal,thesamplingfrequencyFs,andthetransformintervallengthNofDFT.Theexactanalogfrequencyfkcorrespondingtothefrequencyindexk,canbedeterminedusingtheformula（）.

答案:

fk=2fh×k/N

第五章測試

ThestraightforwardimplementationoftheDFTisofhigherefficiency,andFFTisnotnecessary.（）

答案:

錯

Tocomputethe256-pointDFTbymeansofdirectimplementation,weneed（）complexmultiplications.

答案:

256×256

DFTistherealizationmethodofFourierTransformtheoretically.

（）

答案:

對

FFTbecomesrealizationmethodofFourierTransformtheoretically.（）

答案:

錯

Onebutterflyoperationunitneeds（）.

答案:

1complexmultiplicationand2complexadditions

TheformsofbasicbutterflyunitforDIT-FFTandDIF-FFTalgorithmsaredifferent.（）

答案:

對

FortheDIF-FFTalgorithmwithradix-2,theinputinthecompleteflowgraphisofbit-reverseddecimalindex,andtheoutputisofnormal-orderdecimalindex.（）

答案:

錯

N-PointFFTsoftworealsequencescanbeimplementedusingtheN-pointFFTofasinglecomplexsequence.（）

答案:

對

IFFTalgorithmscanbeimplementedbythesmallchangesinFFTFlowGraph.（）

答案:

對

IFFTalgorithmscanbeimplementedbyaddingpretreatmentandposttreatmentofFFT.（）

答案:

對

第六章測試

Theactualimplementationofadigitalfiltercouldbeeitherinsoftwareorhardware,dependingonpracticalapplications.（）

答案:

對

Underfinite-precisionarithmetic,anygivenrealizationofadigitalfilterbehavesidenticallytoanyotherequivalentstructure.（）

答案:

錯

ForthecascadestructureofaIIRsystem,whichoneisnotitsadvantageinthefollowingoptions?（）

答案:

Errorswillnotaccumulatestepbystep

InthecascadedorparallelstructuresofIIRfilters,thefirst-ordersectionandsecond-ordersectionaregenerallyusedassubsystems,whichareimplementedin（）.

答案:

directform

ThesystemfunctionofFIRDFcanalsobeconsideredasanIIRDFwhosedenominatorpolynomialis1,andthefeedbackcoefficientsindirectformareequaltozero.（）

答案:

對

Owingtosymmetryproperties,thefiltercanberealizedbylinearphasestructurethatcontainsmultipliersonlyaboutahalfoftheorderofthefilter.（）

答案:

對

ForFIRdigitalfilters,thesignalflowgraphoflinearphaseformisindependentoftheevenoroddlengthNofimpulseresponseh(n).（）

答案:

錯

第七章測試

AwidelyusedapproachtoIIRfilterdesignisbasedontheconversionofaprototypeanalogtransferfunctiontoadigitaltransferfunction.（）

答案:

對

DigitalfiltersareveryimportantpartofDSP,whichhastwouses:signalseparationandsignalrestoration.（）

答案:

對

Forapracticaldigitalfilter,themagnituderesponseinthepassbandandinthestopbandareofnoanyacceptabletolerances.（）

答案:

錯

Themagnitudefrequencycharacteristiccurveofadigitalfilterisshowninthebelowfigure,indicatingthatthefiltertypeis（）.

答案:

high-passfilter

Fordigitalfilterdesign,normalizedbandedgefrequenciesneedtobecomputedfromspecificationsinHzusingtheformula.（）

答案:

對

AsforthepropertiesoftheButterworthlow-passfiller,whicharecorrectforthefollowingstatements？（）

答案:

Asthefilterorderincreases,thecharacteristicsbecomesharper.;Themagnituderesponseisamonotonicallydecreasing.;TheDCgainofthefilterisunityforanyorder;The3-dBbandwidthisunrelatedtothefilterorder.

ThemagnitudefrequencyresponseofChebyshevfiltersisofequiripplecharacteristicsinboththepassbandandstopband.（）

答案:

錯

BylookinguptheknowntableaccordingtotheorderN,wecanobtainthenormalizedtransferfunctionHa(p),whichisindependentto3dBcutofffrequencyΩc.（）

答案:

對

AsfortheimpulseinvariancetransformationofIIRdigitalfilter,theanalogfrequenciesanddigitalfrequenciesarerelatedbylinearrelationship.（）

答案:

對

Thealiasingdistortionisunavoidableintheimpulseinvariancetransformation.（）

答案:

對

AsforthebilineartransformationofIIRdigitalfilter,itisamany-to-onemappingrelationshipfroms-planetoz-plane.（）

答案:

錯

AsforthebilineartransformationofIIRdigitalfilter,transformtransferfunctionHa(s)ofanalogfilterintotransferfunctionH(z)ofdigitalfilterbytheformula（）.

答案:

第八章測試

AsforFIRdigitalfilterdesign,thestabilityisnotadesignissueasthetransferfunctionisapolynomialinz-1andisthusalwaysguaranteedstable.（）

答案:

對

Forthefollowingoptions，whicharenotthedesignmethodforFIRdigitalfilters？（）

答案:

impulseinvarianttransformation;bilineartransformation

AsforType2Linear-PhaseFIRFilter,thefilterisnotsuitablefordesigningahigh-passandband-stopfilterowingtotheidentityequation.（）

答案:

對

AsforType3Linear-PhaseFIRFilter,isantisymmetric,i.e.,andisnotnecessarilyequaltozero.（）

答案:

錯

AsforconstraintsonzerolocationsforLinear-PhaseFIRFilter,whicharecorrectforthefollowingstatements?（）

答案:

Zerosmustbeonecomplex-conjugatepairofzerosstandingontheunitcircle,whenzerosdonotlieonreal-axis,anddoeslieontheunitcircle.;Zerosmustbetworealzeros