On the optimal solutions of beamformer assisted acoustic echo cancellers

Acoustic echo cancellation constitutes a major challenge for full-duplex communication and human-machine speech interaction. Beamforming is a well-known technique for suppression of local interferers, including acoustic echoes. Those techniques can be combined to jointly achieve better echo cancellation at an additional computational cost. Experimental results available in the literature show significant increase in echo cancellation performance when assisted by a beamformer. Different implementation schemes have been proposed. Performance comparisons of these solutions have been mostly experimental, which limits the generalization of the results. This work compares the optimal solutions provided by the original cascaded BF-AEC structure and by the alternative scheme that jointly optimizes the beamformer and the acoustic echo canceler coefficients.