实验一(系统响应及系统稳定性)

FFTIIRFIRIIR10.1:1.1232.MATLABfilterMATLABconv[19]nn31filterconv2)1(9.0)1(05.0)(05.0)(nynxnxny)()(81nRnx)()(2nunxa))()(81nRnx)()(2nunxb)3)()(101nRnh)3()2(5.2)1(5.2)()(2nnnnnhh1(n)h2(n))()(81nRnx4)2()()2(9801.0)1(8237.1)(00nxbnxbnynyny49.100/10b0.4rada))(nub))4.0sin()014.0sin()(nnnx4(1)?251234510.1.2%1closeall;clearall%======1filteru(n)======A=[1,-0.9];B=[0.05,0.05];%BAx1n=[11111111zeros(1,50)];%x1(n)=R8(n)x2n=ones(1,128);%x2(n)=u(n)hn=impz(B,A,58);%h(n)subplot(2,2,1);y='h(n)';tstem(hn,y);%tstemtitle('(a)h(n)');boxony1n=filter(B,A,x1n);%x1(n)y1(n)subplot(2,2,2);y='y1(n)';tstem(y1n,y);title('(b)R8(n)y1(n)');boxony2n=filter(B,A,x2n);%x2(n)y2(n)subplot(2,2,4);y='y2(n)';tstem(y2n,y);title('(c)u(n)y2(n)');boxon%===2conv============================x1n=[11111111];%x1(n)=R8(n)h1n=[ones(1,10)zeros(1,10)];h2n=[12.52.51zeros(1,10)];y21n=conv(h1n,x1n);y22n=conv(h2n,x1n);figure(2)subplot(2,2,1);y='h1(n)';tstem(h1n,y);%tstemtitle('(d)h1(n)');boxonsubplot(2,2,2);y='y21(n)';tstem(y21n,y);title('(e)h1(n)R8(n)y21(n)');boxonsubplot(2,2,3);y='h2(n)';tstem(h2n,y);%tstemtitle('(f)h2(n)');boxonsubplot(2,2,4);y='y22(n)';tstem(y22n,y);title('(g)h2(n)R8(n)y22(n)');boxon%=========3========================un=ones(1,256);%u(n)n=0:255;xsin=sin(0.014*n)+sin(0.4*n);%A=[1,-1.8237,0.9801];B=[1/100.49,0,-1/100.49];%BAy31n=filter(B,A,un);%u(n)y31(n)y32n=filter(B,A,xsin);%u(n)y31(n)figure(3)subplot(2,1,1);y='y31(n)';tstem(y31n,y);title('(h)u(n)y31(n)');boxonsubplot(2,1,2);y='y32(n)';tstem(y32n,y);title('(i)y32(n)');boxonfunctiontstem(xn,yn)%%xn:yn:n=0:length(xn)-1;stem(n,xn,'.');boxonxlabel('n');ylabel(yn);axis([0,n(end),min(xn),1.2*max(xn)])10.1.310.1.12)()(81nRnx)()(2nunx(a)(b)(c)3h1(n)h2(n))()(81nRnx(e)(g)4)(nu)4.0sin()014.0sin()(nnnx(h)(i)(h))(nu(i))4.0sin()014.0sin()(nnnxsin(0.4)n0.4rad020400.020.040.060.080.1nh(n)(a)h(n)020400.20.40.6ny1(n)(b)R8(n)y1(n)0501000.20.40.60.81ny2(n)(c)u(n)y2(n)05101500.51nh1(n)(d)h1(n)0102002468ny21(n)(e)h1(n)R8(n)y21(n)05100123nh2(n)(f)h2(n)0510152002468ny22(n)(g)h2(n)R8(n)y22(n)050100150200250-0.04-0.0200.020.04ny31(n)(h)u(n)y31(n)050100150200250-0.500.51ny32(n)(i)y32(n)10.1.110.1.4(1)h(n)2110.1.1(a)(b)(c)()n)()(81nRnx)()(2nunx