Non-linear acoustic echo cancellation using online loudspeaker linearization

This paper presents an approach to non-linear acoustic echo cancellation (AEC).We first present the model of a loudspeaker enclosure microphone system which is divided into two blocks: a non-linear, power filter model for the down-link path (loudspeaker and amplifiers) and a linear model for the acoustic channel and up-link path. Using this model we propose an approach that uses loudspeaker linearization and linear AEC to improve performance of an otherwise classical approach to linear AEC. The novel contribution in this paper relates to a new on-line linearization pre-processing algorithm that adapts to long-term variations in the loudspeaker characteristics. This feature contrasts with fixed pre-processor aglorithms which have been reported previously.