4.m

离散序列的仿真

% s[n]
n=0:499;
A=1;
phase=0;
arg=0.1*pi*n-phase;
x=A*sin(arg);
n1=0:499;
clf;
subplot(3,1,1);
stem(n,x);
title('x');
xlabel('n');
ylabel('x');
h=random('unif',0,2,1,500);
a=mean(h);
y=h-a;
subplot(3,1,2);
stem(n,y);
title('y');
xlabel('n');
ylabel('y');
z=x+y;
subplot(3,1,3);
stem(n1,z);
title('z');
xlabel('n');
ylabel('z');
axis([0 499 -40 40]);

    n=0:499;
f=0.1;
phase=0;
A=1;
arg=f*pi*n-phase;
x=A*sin(arg);
rpx=xcorr(x);
clf;
n1=-499:499
stem(n1,rxx);
axis([-499 499 -240 240]);
grid;
title('rpx');
xlabel('x');
ylabel('t');

   n=0:499;
A=1;
phase=0;
arg=0.1*pi*n-phase;
a=sin(arg);
h=random('unif',0,2,1,500);
c=mean(h);
b=h-c;
x=a+b;
y=[1 zeros(1,19)];
yt=y'*ones(1,25);
yt=(yt(:))';
z=xcorr(x,yt);
n1=-499:499;
clf;
stem(n1,z);
axis([-500 500 -30 30]);
title('rxy');
xlabel('n');
ylabel('y');