Adaptive array processing: Time vs. frequency domain

The approach to adaptive array procesing typically has taken one of two paths - time domain (wide band) or frequency domain (narrow band). In the former, the entire frequency range of interest is processed as a whole with a multichannel tapped delay line adaptive filter providing frequency selectivity. In the latter, the desired passband is broken into independent contiguous pieces each of which is processed independently via two quadrature weights per channel. This paper investigates the tradeoffs in each approach and the conditions under which they are equivalent.