Robust microphone array processor incorporating headshadow effects

An approach for beamforming in the presence of coherent signals is developed. The correlation between a desired signal and an interferer is broken down by virtual dithering of a beamspace array. The technique can be applied to arbitrary array geometries. Simulation results are presented for narrowband signals for two array geometries: a linear equispaced array and a semicircular array which incorporates the effects of acoustic headshadow. The linear equispace array results allow comparison of this method to spatial smoothing, while the headshadow array results demonstrate the usefulness of the approach for an array which is quite dissimilar to the uniform linear array