In my master thesis I am trying to implement a beamformer.
I've already done the delay-sum part 1 year ago. I have been told:
in FIR filtering we can do
FFT --> null the unwanted frequency bin --> IFFT .
We can to the same in beamformers. If we know the interference DOA (like 0 in angle 25 and 1 in everywhere else between -90 to 90) output we can ---> IFFT and use the weights in aparture elements.
Whatever I tried it didn't work. Than I begin to read books , surprisingly couldn't find the method that my advisor told me. Instead I found out methods like MVDR, LCMV. Now I am tring to use matlab method lcmvweights to get correct weights for each element and apply in my delay-sum beamformer. Even I succeed to use this method I am curious if narrowband-beamformers could be used in complex signals like speech?