Problem 2: Repeat Problem 1 but using the indirect method and the Wiener-Khinchine Theorem. Use the MATLAB function "xcorr.m" with the 'unbiased' option, e.g., x=spec(1,:); % Get first row of signal matrix rxx=xcorr(x,'unbiased'); Also window the resulting autocorrelation which will have length 1023 by taking the approximate center: rxx=rxx(512-256 : 512+256); Answer the question as to why a window should be used. Next, apply the W-K Theorem: Sxx=fftshift(fft(rxx)); Finally since rxx is not quite symmetric(off by one sample), one needs to find the complex modulus to fold imaginary power to real-valued: Sxx=abs(Sxx)