Can anyone help with cross correlation error in Simulink? I am sorry if I say any thing silly. I have a vector x below and trying to implement correlation with itself (lets say x2) in Simulink, but getting error. I am getting all zeros in result of my output vector. Kindly can some one please help me out in it. Thanks in advance.

ts=1*10^-9;
t=0*10^-9:ts:150*10^-9;
fc=1*10^6;
yi=154*10^-9:ts:2000*10^-9;
y=yi*0;
xi=2*sin(2*pi*fc*t);
x=[xi y];
x2=x;
z=xcorr(x2,x);
The edited code in your question should not result in an all-zero vector. Of course, since x contains many zeros, the autocorrelation also has many zeros, but it's non-zero in its center portion (i.e., around index $2000$).

Also note that you don't need to define a second identical vector to compute the autocorrelation. You can use the command z = xcorr(x);