Design of Optimum Sparse Array for Robust MVDR Beamforming Against DOA Mismatch

The adaptive beamforming performance using a given number of antennas can be improved by configuring an optimum sparse array. Existing sparse array designing methods for adaptive beamforming assume prior knowledge of exact source directions-of-arrival (DOAs), which may not be applicable in navigation or other sensing situations. The sensitivity of sparse array configurations against uncertainty of source signal DOAs is examined. We seek the optimum sparse array that is robust to the source angular bias, enabling the output signal-to-noise ratio or signal-to-interference-plus-noise ratio to be minimally degraded. Numerical examples are presented to validate the effectiveness of the configured robust sparse arrays in the presence of arbitrary DOA uncertainties.