I have a small question on FFT based adaptive beamforming based on Spectral Matrix Inversion technique.
I have estimated the Spectral Matrix (Sxx) from my data by dividing it into blocks and averaging them for each bin, to get sufficient rank on the matrix.
Now my question is :
To produce the MVDR weighting vector (8x1 vector in my case since I have 8 microphones) for each bin, I multiply the inverse of Sxx for each bin (say bin#1) with the steering vector 'a' given by exp(i*2*pi*D*omega), where D is the set of time delays(8x1 vector) pointing towards look direction(say +10°). Here what should be 'omega'? Isit equal to the first frequency bin of data from first channel and so on for all the bins? please clarify.