Performance comparison of adaptive subband structures applied to acoustic echo cancelling

Subband adaptive filtering has been recently studied by a large number of researchers. Subband structures with non-critical sampling of the subband signals have been frequently employed in order to avoid aliasing effects. Recently, new subband structures with critical sampling have been developed in which the aliasing between adjacent subbands is completely cancelled. In this paper, the convergence behavior and the computational complexity of oversampled and critically sampled subband structures are compared for the acoustic echo cancelling application. A theoretical convergence analysis is presented, from which the convergence rates can be estimated.