An efficient post-processing filter for multi-channel acoustic echo cancellation system

Abstract

The acoustic echo usually cannot be totally removed by the adaptive filter due to the insufficient filter taps, nonlinearity of the echo path transfer function, and the background noise. A post-processing filter, which aims to suppress the residual echo, thus plays an important role in the acoustic echo cancellation system. In this paper, an efficient post filter is proposed based on the coherence between the error signal and the echo estimation of the adaptive filter. The proposed method can be seamlessly combined with the multi-delay frequency-domain adaptive filter. Furthermore, it can be easily extended to multi-channel processing. The instrumental evaluation and listening test both demonstrate the superiority of the proposed method.