Adaptive array cancellation of multipath interference

The steady-state performance of a narrowband adaptive array processor using a single auxiliary tapped delay line is analyzed for a simple two-path interference scenario, and computer solutions are presented for various combinations of signal and multipath parameters. It is shown that auxiliary delay taps are required for effective cancellation of multipath interference, even for fractional bandwidth-delay products. Good cancellation is generally achieved provided that (a) the delay line taps are spaced somewhat closer than the Nyquist sampling rate, and (b) the total length of the delay line considerably exceeds the longest multipath delay, depending on multipath component strengths. A simple impulse response model is also developed to provide an understanding of the behavior of cancellation performance and how it relates to the various parameters involved.