An assessment of linear adaptive filter performance with nonlinear distortions

Acoustic echo cancellers are generally based on the assumption of a linear echo path between the transducers. However the small loudspeakers that are commonly used in todays terminals can introduce nonlinear distortions that reduce the performance of echo cancellation. In order to evaluate the degradation in performance, this paper assesses the behaviour of five linear echo cancellers in the presence of nonlinearities and presents the first thorough comparison of their robustness. Even if the performance of all the echo cancellers degrades as expected, some algorithms are shown to be more robust than others: fast converging algorithms and block signal processing are more perturbed in nonlinear environments.