Multichannel filtering for optimum noise reduction in microphone arrays

Introduces an optimization criterion for the design of microphone arrays, and derives an optimum filter based on this criterion. The algorithm computes two separate correlation matrices for the signal: one for when only background noise is present, and one for when both noise and signal are present. A filter is then computed based on these matrices, optimizing the proposed weighted mean-square error criterion. A block-recursive version of the algorithm is presented, using LMS-like adaptation of the multichannel filters, with a computational complexity under 40 MIPS for a typical application with four microphones. Simulation results with typical office noise show improvements of up to 20 dB in signal-to-noise ratio, even in low-noise environments