A practical adaptive blind multichannel estimation algorithm with application to acoustic impulse responses

We propose a noise robust adaptive blind multichannel identification algorithm for acoustic impulse responses. It has been known that the normalised multichannel frequency domain least-mean-square (NMCFLMS) algorithm misconverges under low signal-to-noise ratio. The coefficients of NMCFLMS converge initially toward the true impulse response after which they then misconverge. The extended NMCFLMS (ext-NMCFLMS) algorithm which has been proposed to mitigate this misconvergence problem assumes the knowledge of magnitude and time-differences-of-arrival (TDOA) of the direct paths for the acoustic impulse responses. In this work, we show how the TDOA can be obtained. More importantly, we present a novel approach to estimate the magnitude of the direct path component under practical conditions. We then show how these estimates can be incorporated to the proposed ext-NMCFLMS with direct path estimation algorithm. We analyze how errors in these estimates affect the performance of the proposed algorithm.