A new robust adaptation mode controller based on a normalized cross-correlation with multiple symmetric leaky blocking matrices for adaptive microphone arrays

This paper proposes an adaptation mode controller (AMC) based on a normalized cross-correlation with multiple symmetric leaky blocking matrices (SLBMs) for adaptive microphone arrays. Robust and wideband estimation of a signal-to-interference ratio (SIR) is performed by the use of multiple pairs of SLBMs. The SIR estimate is compared to theoretical thresholds to evaluate target-interference proportion for controlling filter-coefficient adaptation in the adaptive path of the beamformer. A design method for SLBMs is developed with an example. Evaluations with recorded signals show that the proposed AMC achieves better discrimination between speech-dominant and interference-dominant sections, resulting in desirable control of coefficient adaptation in the microphone array. The better output signal of the microphone array, due to its good control, provides a speech recognition rate by as much as 11% higher than the conventional AMC.