WARP-AEC: A stereo acoustic echo canceller based on W-Adaptive filters for Rapid Projection

It is difficult for stereo acoustic echo cancellers to converge toward real stereo echo path characteristics in the case of strong cross-channel correlation in right and left channel signals. To overcome this problem, we propose the WARP (W-Adaptive filters for Rapid Projection) method, which uses a monaural adaptive filter in parallel with a stereo adaptive filter. In this method, stereo echo path estimation is realized by projecting from two monaural estimated echo path characteristics at a far-end talker change. Stereo echo path estimation error, which is gradually decreased in conventional methods, is quickly improved at a far-end talker change by adopting the WARP method. This method has been evaluated by using 5 talker position's stereo signals with/without 10% level drift in right and left channels. The results showed that there was a 15-20dB improvement in estimation error at a far-end talker change compared with estimation errors in conventional methods, such as MC-NLMS and Affine projection method with p=3 in the case of WGN, and that there were more than 10 dB echo path estimation error improvement and 20-30 dB residual echo level improvement in the case of voice source.