《假定重构滤波器是带宽为的理想低通滤波器具有带通增.doc》由会员分享，可在线阅读，更多相关《假定重构滤波器是带宽为的理想低通滤波器具有带通增.doc（2页珍藏版）》请在金锄头文库上搜索。
1、使用每秒10个采样的频率，对信号进行采样，画出原始信号的傅立叶变换X(f) 和理想采样信号的傅立叶变换。假定重构滤波器是带宽为的理想低通滤波器，具有带通增益，画出重构滤波器的输出t=0:0.001:2;x=5*cos(6*pi*t)+3*sin(8*pi*t);figure(1);subplot(2,1,1);plot(t,x);xlabel(t);ylabel(x(t);title(原始信号);dt=0.1;wm=2*pi*10;n=length(t);k=0:n-1;w=k*wm/n;x1=x*exp(-j*t*w)*dt;subplot(2,1,2);plot(w/(2*pi),abs(
2、x1);xlabel(f(Hz);ylabel(X(f);title(原始信号频谱);fs=10;ts=1/fs;n1=0:ts:20;xa=5*cos(6*pi*n1*ts)+3*sin(8*pi*n1*ts);figure(2);subplot(2,1,1);stem(n1,xa);xlabel(t);ylabel(x_a(t);title(时域抽样信号);x=5*cos(6*pi*n1)+3*sin(8*pi*n1);wm=2*pi*10;n=length(t);k=0:n-1;w=k*wm/n;x2=x*exp(-j*n1*w)*ts;subplot(2,1,2);plot(w/(2*
3、pi),abs(x2)xlabel(f(Hz);ylabel(X_a(f);title(抽样信号频谱);t=0:0.001:2;x3=5*cos(6*pi*t)+3*sin(8*pi*t);figure(3);subplot(4,1,1);plot(t,x3);xlabel(t);ylabel(x(t);title(原始信号);fs=10;ts=1/fs; n4=0:3/ts; t1=0:ts:2;x4=5*cos(6*pi*n4/fs)+3*sin(8*pi*n4/fs); T_N=ones(length(n4),1)*t1-n4*ts*ones(1,length(t1); xa=x4*si
4、nc(fs*pi*T_N); subplot(4,1,2),plot(t1,xa);axis(min(t1) max(t1) 1.1*min(xa) max(xa);xlabel(t);ylabel(x_a(t);title(时域卷积原时域信号(fs=10);fs1=25;ts=1/fs1; n4=0:3/ts; t1=0:ts:2;x5=5*cos(6*pi*n4/fs1)+3*sin(8*pi*n4/fs1); T_N=ones(length(n4),1)*t1-n4*ts*ones(1,length(t1); xa1=x5*sinc(fs1*pi*T_N); subplot(4,1,3)
5、,plot(t1,xa1);axis(min(t1) max(t1) 1.1*min(xa1) max(xa1);xlabel(t);ylabel(x_a(t);title(时域卷积原时域信号(fs=25)fs2=50;ts=1/fs2; n4=0:3/ts; t1=0:ts:2;x6=5*cos(6*pi*n4/fs2)+3*sin(8*pi*n4/fs2); T_N=ones(length(n4),1)*t1-n4*ts*ones(1,length(t1); xa2=x6*sinc(fs*pi*T_N); subplot(4,1,4),plot(t1,xa2);axis(min(t1) max(t1) 1.1*min(xa2) max(xa2);xlabel(t);ylabel(x_a(t);title(时域卷积原时域信号(fs=50);
