山东大学信号与系统-2013年试卷B

2011-2012学年学期题号一二三四五六七八九十总分总分人得分一、PART1CHOOSINGTHEBESTANSWER(30points)(ArrangetheanswersforallquestionsintothefollowingTable.)Questionnumber12345678910AnswerTheinput/outputrelationshipofthecontinuous-timesystemisgivenby.Thesystemis________.Hasmemory,linearandtime-invariantsystemHasmemory,linearandtime-varyingsystemHasmemory,nonlinearandtime-invariantsystemInthefollowingsignals,whichoneisperiodic?B.C.Givenalineartime-invariantcausalsystemwithnoinitialenergy,theunitpulseresponseish[n],ifinputsignalx[n],thezerostateresponsey[n]is________.二、※※※※※※※※※※※※※※※※※※※※※※※※※※※Theperiodicsignalhas,thenon-periodicsignalhas.Continuousamplitudespectrum,ContinuousamplitudespectrumContinuousamplitudespectrum,LineamplitudespectrumLineamplitudespectrum,ContinuousamplitudespectrumAstablelineartime-invariant(LTI)continuous-timesystem,theunitimpulseresponseish(t)=(2e-t+e-2t)u(t).Thenpolesofthesystemare______.p1=0,p2=-1,p3=-2p1=0,p2=-1p1=-1,p2=-2Thesignalsx(t)andy(t)areshowninthefollowingfigure,SupposethattheFourierTransformofx(t)is,thenis_______.Theinput/outputrelationshipofthecontinuous-timeLTIsystemis.ThesystemtransferfunctionH(s)is______.山东大学信号与系统课程试卷学院专业班级学号姓名……密…………封…………线…………………第1页共6页

2011-2012学年学期AfeedbackconnectionsystemisshowninfollowingFigure,thesystemtransferfunctionH(s)is________.Givenalineartime-invariantstablesystem,theformofzeroinputresponseisdeterminedby______.thesystemtheinitialconditionsthesystemandtheinitialconditionsThemagnitudefunctionoftheidealfilterisgivenby,theidealfilteris_________.anidealhigh-passfilteranidealband-stopfilteranideallow-passfilterPART2ANSWERTHEFOLLOWINGQUESTIONS(40points)题号12345678总分数分数Givenalineartime-invariantcontinuous-timesystemwithnoinitialconditions.Theinputx(t)andoutputy(t)areshownbelowasthefollowingfigurea)andb).Plotthey(t)withinputx(t-3)and(1/2)x(t).Forthefollowinglineartime-invariantcontinuous-timesystems,determineifthesystemisstable,marginallystableorunstable.山东大学信号与系统课程试卷学院专业级学号姓名……密…………封…………线…………………第2页共6页2010-20112010-2011学年1学期Alineartimeinvariantcontinuous-timesystemrespondstothefollowinginputswiththecorrespondingoutputs:if,thenandif,then,findforForthefollowingdifferenceequations,computey[n]forn=1,2,3,whenx[n]=u[n]andy[-1]=2.5.Supposethatandtheobjectiveistofindtheoutputresultingfromthesinusoidalinput.Anideallinear-phaselowpassfilterh(t)hasfrequencyresponsefunctiona.Computetheimpulseresponseh(t)ofthefilter.b.Computetheresponsey(t)whentheinputx(t)=sin5t.山东大学信号与系统课程试卷学院专业级学号姓名……密…………封…………线…………………第3页共6页2011-2012学年学期Supposethattheinputisappliedtoacausallineartime-invariantcontinuous-timesystemandthattheresultingoutputresponseis.Determinethetransferfunctionforthesystem.Alineartime-invariantcontinuous-timesystemhastransferfunction.Theinputisappliedtothesystemforwithzeroinitialconditions.Theresultingsteady-stateresponseis,compute,andPART3COMPUTEANDANSWERTHEFOLLOWINGQUESTIONS(30points)题号12345总分数分数Givenasystem,thedifferentialequationis.Theinputsignal，initialconditionsare,.Computetheimpulseresponseh(t),thezeroinputresponsey1(t)，zerostateresponsey2(t)andthecompleteresponsey(t).山东大学信号与系统课程试卷学院专业级学号姓名……密…………封…………线…………………第4页共6页

2011-2012学年1学期computethetransferfunctionforthefollowingsystemConsiderthefollowingsamplingandreconstructionconfiguration:Theoutputy(t)oftheidealreconstructioncanbefoundbysendingthesampledsignalthroughanideallowpassfilterwiththefrequencyresponsefunctionLetandT=0.01sec.Draw,where,determiningifaliasingoccurs.Determinetheexpressionfory(t).山东大学信号与系统课程试卷学院专业级学号姓名……密…………封…………线…………………第5页共6页

2011-2012学年学期4.Alineartime-invariantcontinuous-timesystemhastransferfunctionComputethesteady-stateandtransientresponsesresultingfromtheinputwithnoinitialenergyatt=0.(Thelaplacetransformpair)5.Acircuitisshownbelow,compu