Post date: Jun 08, 2015 4:48:33 PM
A common assumption in array signal processing is the narrow-band assumption on the source signal [1]. If
is narrow-band, its Fourier transform for , where is small. Thus a delay in
results in a negligible phase shift to at every . Namely,
or
This assumption can be used to make the complex representation of the delayed source signal simple. If
then
[1] http://web.media.mit.edu/~aggelos/papers/roykailath89.pdf