实验四线性时不变离散时间系统的频域分析.doc

Name:ChenyifanSection:LaboratoryExercise4LINEAR,TIME-INVARIANTDISCRETE-TIMESYSTEMS:FREQUENCY- TransferFunctionAnalysisAnswers: puteandplotthemagnitudeandphasespectraofamovingaveragefilterofEq.()for0w2pisshownbelow: <-file(s)andpaste.>w=0:pi/511:2*pi;M=input('M=');num=ones(1,M)/M;h=freqz(num,1,w);subplot(2,1,1);plot(w/pi,abs(h));grid;title('H(e^{j\omega})幅度谱');xlabel('\omega/\pi');ylabel('振幅');subplot(2,1,2);plot(w/pi,angle(h));grid;title('相位谱H(e^{j\omega})');xlabel('\omega/\pi');ylabel('以弧度为单位的相位'); ThisprogramwasrunforthefollowingthreedifferentvaluesofMandtheplotsofthecorrespondingfrequencyresponsesareshownbelow:<InsertMATLABfigure(s)(s)andpaste.> Thetypesofsymmetriesexhibitedbythemagnitudeandphasespectraaredueto- ThetypeoffilterrepresentedbythemovingaveragefilterisM=3-M=10;M=20; -Bythegraph,youcanseethatitrepresentsalow- TheplotofthefrequencyresponseofthecausalLTIdiscrete-:<InsertMATLABfigure(s)(s)andpaste.>w=0:pi/511:pi;num=[-];den=[1-];h=freqz(num,den,w);subplot(2,1,1);plot(w/pi,abs(h));grid;title('H(e^{j\omega})幅度谱');xlabel('\omega/\pi');ylabel('振幅');subplot(2,1,2);plot(w/pi,angle(h));grid;title('相位谱H(e^{j\omega})');xlabel('\omega/\pi');ylabel('以弧度为单位的相位'); Thetypeoffilterrepresentedbythistransferfunctionis- TheplotofthefrequencyresponseofthecausalLTIdiscrete-:<InsertMATLABfigure(s)(s)andpaste.>w=0:pi/511:pi;num=[-];den=[-]h=freqz(num,den,w);subplot(2,1,1);plot(w/pi,abs(h));grid;title('H(e^{j\omega})幅度谱');xlabel('\omega/\pi');ylabel('振幅');subplot(2,1,2);plot(w/pi,angle(h));grid;title('相位谱H(e^{j\omega})'