A residual echo suppression technique for systems with nonlinear acoustic echo paths

Linear acoustic echo cancellers are widely employed to enhance the quality of telecommunication systems. However, low-cost audio components may generate significant nonlinear distortions in the acoustic echo path, which degrades the performance of adaptive linear acoustic echo cancellers (AECs), thus motivating the nonlinear AEC research. In this paper, we propose to use a postfilter to further attenuate the nonlinear residual echo following a linear AEC. The postfilter design is based on the power spectral density (PSD) of the nonlinear residual echo. By modeling the nonlinearity in the system using a basis expansion form, the PSD estimate becomes independent of the length of the room impulse response. The performance of the proposed algorithm is illustrated by computer simulations.