Nonlinear acoustic echo cancellation using adaptive orthogonalized power filters

In acoustic echo cancellation as, e.g., for mobile communication receivers, loudspeakers and their amplifiers cause significant nonlinear distortion in the echo path, resulting in a degradation of the performance of linear echo cancelers. In order to cope with this type of nonlinear echo path, we discuss an orthogonalized version of power filter that can be considered as a parallelized realization of the cascade of a memoryless polynomial followed by a linear filter. As, in the echo cancellation context, the statistics of the speech input are non-stationary and not known in advance, the orthogonalization follows the signal statistics. The performance of the resulting novel nonlinear structure is evaluated by experiments using real hardware.