[SOLVED] How to Spectrum Estimate using Welch with Overlap?

[asustant]

Hi all. I'm doing some spectrum estimation. Here are codes, I used Welch method (without using pwelch func.) with no overlap. Now I want to do it with %50 overlap to see the difference, which parts should I change for this purpose?

 Fs = 8000; 
 x  = y1;         %80x1 matrix
 Nx = length(x);

 w = hann(Nx);
 xw = x.*w; 

 nfft = Nx; 
 X = fft(xw,nfft);
 mx = abs(X).^2; 

 mx = mx/(w'*w); 
 NumUniquePts = nfft/2+1; 
 mx = mx(1:NumUniquePts);
 mx(2:end-1) = mx(2:end-1)*2;

 Pxx1 = mx/Fs;