An Improved structure of Acoustic Echo Cancellation Using Blind Source Separation

Abstract

An acoustic echo canceller (AEC) is often used to eliminate acoustic echoes generated in a hands-free communication system. AEC approximates the echo path using an adaptive filter and eliminates the acoustic echo by subtracting the echo replica generated using the filter from the observed signal. However, conventional adaptive algorithms for updating filters fail to estimate during double talk periods when both acoustic echo and near-end speech are observed. In recent years, it was shown that blind source separation (BSS) can be used for echo cancellation during double talk period. However, the convergence speed is slower than the convergence speed of the conventional method. In our previous research we proposed combining conventional AEC and BSS, where BSS was used as preprocessor of adaptive filter to perform echo cancellation. Since there is room for improvement in the echo cancellation performance in previous research, in this paper we propose a new approach using BSS alternative output as AEC input. Simulation results show that the proposed system is effective for echo path estimation when echo path fluctuation occurs during double talk period.