A combined FDAF/WSAF algorithm for stereophonic acoustic echo cancellation

Adaptive acoustic echo cancellation in stereophonic teleconferencing is a very demanding application. The characteristics are: a very large number of coefficients, non-stationary input (speech), (slowly) time-varying systems to be identified, plus the specific property that both stereo signals are intrinsically very correlated. Basic versions of stochastic gradient algorithms have difficulties in meeting these requirements. We show that, in a multichannel framework, only a combination of techniques can result in an algorithm which convergence is governed by a quasi-diagonal matrix. Simulations with data recorded in a conference room demonstrate the improvement in convergence of our algorithm compared to the LMS.