参考的信号课设.doc

正弦信号%绘制连续时间信号的时域波形t=0:0.001:0.2;y=cos(2*pi*10*t);subplot(211);plot(t,y);xlabel(t 单位:s,Fontsize,8);title(连续时间信号f(t) cos(20*pi*t);%绘制抽样后的时域信号subplot(212);plot(t,y,b:);hold on;t2=cos(2*pi*10*t2);stem(t2,y2,filled);xlabel(t 单位:s,Fontsize,8);title(抽样信号 fs(t);hold off;图形周期矩形脉冲信号%绘制周期方波信号t=0:0.01:100;y=square(t);subplot(311);plot(t,y);axis(0,10,-3,3);title(周期方波信号);%绘制抽样后的方波信号subplot(312);plot(t,y,b:);hold on;t2=0:1/100:0.01;y2=square(t2);stem(t2,y2);axis(0,10,-3,3);title(抽样信号 fs(t);hold off;图形f1=3,2,1,1,1,2;k1=-3:2;f2=0:5;k2=-1:4;f1=3,2,1,1,1,2;k1=-3:2;f2=0:5;k2=-1:4;k=min(min(k1),min(k2):max(max(max(k1),max(k2);s1=zeros(1,length(k);s2=s1;i1=find(k=min(k1)&(k=min(k2)&(k=max(k2)=1)s2(i2)=f2N=64;n=0:1:N-1;x=randn(1,n);k=0:1:N-1;y=x*(exp(-j*pi/N).(n*k);subplot(3,1,1);stem(n,x,filled);title();subplot(3,1,2);stem(k,abs(y);title();subplot(3,1,3);stem(k,angle(y);title();混叠%绘制连续时间信号的时域波形t=0:0.001:40;y=cos(2/3*pi*t);subplot(121);plot(t,y);axis(0 6 -1.1 1.1)xlabel(t 单位:s,Fontsize,8);title(连续时间信号f(t);line(0 6,0 0,color,0 0 0);%绘制频谱 N=300;W=2*pi*10;k=-N:N;w=-k*W/N;Y=0.01*y*exp(-j*t*w);Y=abs(Y);subplot(122);plot(w/pi,Y);axis(-2.5,2.5,0,pi*7+0.2);title(连续信号频谱);xlabel(omega 单位:pi);%采样display(please input the value of sample period);Ts=input(Ts=);%绘制采样后时域信号subplot(121);plot(t,y,b:);hold on;t2=0:Ts:40;y2=cos(2/3*pi*t2);stem(t2,y2);axis(0 6 -1.1 1.1);xlabel(t 单位:s,Fontsize,8);title(fs(t);hold off;%绘制采样后时域信号频谱Y2=Ts*y2*exp (-j*t2*w);Y2=1/Ts*abs(Y2);subplot(122);plot(w/pi,Y,b:);xlabel(omega 单位:pi);title(采样后频谱);hold on;plot(w/pi,Y2,r);axis(-2.5,2.5,0,pi10);hold off; 整数倍抽取 t=0:0.00021:1;x=cos(2*pi*30*t);y=decimate(x,4);subplot(121);stem(x(1:120),axis(0 120 -2 2);title(元信号);subplot(122);stem(y(1:30);title(后信号); 泄露n1=input(n1=);n2=input(n2=);n3=n1:n2;k1=length(n3);x1=zeros(1,k);x1(1,-n1+1)=1;subplot(511)x2=ones(1,k1);x2(1,1:n2)=0;subplot(512);stem(n3,x2,filled);title(窗函数);N=20;n=-5:1:N-1;x=sin(n*pi/8)*x2;k=-5:1:N-1;y=x*(exp(-j*2*pi/N).(n*k);subplot(5,1,3);stem(n,x,filled);title();subplot(5,1,4);stem(k,abs(y);title();subplot(5,1,5);stem(k,angle(y);title();a=0:20;b=zeros(1,5),ones(1,8),zeros(1,8);stem(a,b);title( );N=20;n=0:1:N-1;x=sin(n*pi/8)*b;k=0:1:N-1;y=x*(exp(-j*2*pi/N).(n*k);subplot(3,1,1);stem(n,x,filled);title();subplot(3,1,2);stem(k,abs(y);title();subplot(3,1,3);stem(k,angle(y);title();N=20;n=0:1:N-1;b=zeros(1,5),ones(1,8),zeros(1,7);subplot(4,1,1);stem(b);title( );x=sin(n*pi/8)*b;k=0:1:N-1;y=x*(exp(-j*2*pi/N).(n*k);subplot(4,1,2);stem(n,x,filled);title();subplot(4,1,3);stem(k,abs(y);title();subplot(4,1,4);stem(k,angle(y);title();均值离散%正弦 n=-20:20;x=sin(pi/6*n+pi/12);stem(n,x,filled);title();%均值 a=mean(x);ezplot(a);hold on;%方差 b=std(x);%标准差c=b2;连续t=0:0.001:0.2;y=cos(2*pi*10*t);subplot(111);plot(t,y);xlabel(t 单位:s,Font