A Channel Shortening Approach for Nonlinear Acoustic Echo Cancellation

Acoustic echo cancellers (AECs) are critical for enhancing audio quality in many telecommunication systems. The problem is challenging because the long room impulse response slows the convergence rate and increases the computational complexity of the AEC designs. Nonlinearity in the power amplifier or the loudspeaker further exacerbates the problem. In this paper, we propose a novel AEC algorithm when the loudspeaker-enclosure-microphone system is described by a Hammerstein model. We show that by introducing a shortening filter, the length of the "effective" acoustic echo path is reduced considerably. An adaptive algorithm is developed for the proposed nonlinear AEC structure; its effectiveness is illustrated by computer simulations.