Least squares frequency invariant beamforming robust against microphone mismatches

The frequency invariant beamforming for microphone arrays is of great interest in practice for distortionless acoustic signal acquisition. Several design approaches for frequency invariant beamformers (FIBs) have been proposed in the literature. However, most of these approaches assume the ideal microphone characteristics, whose performance deteriorates greatly in the presence of microphone mismatches. To deal with this problem, a robust FIB design approach using least squares criterion is proposed in this paper, which takes the microphone statistical characteristics into consideration. Design examples are shown to demonstrate the effectiveness of the proposed design approach.