ISSN : 1796-2048
Volume : 2    Issue : 2    Date : April 2007

Sub-band Implementation of Adaptive Nonlinear Filter for Adaptive Nonlinear Echo Cancellation
Dayong Zhou, Yunhua Wang, Victor DeBrunner, and Linda DeBrunner
Page(s): 77-82
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The adaptive Volterra filter has been successfully applied in nonlinear acoustic echo cancellation
(AEC) systems and nonlinear line echo cancellation systems, but its applications are limited by its
required computational complexity and slow convergence rate, especially for systems with long
memory length. In this paper, we first apply a more general nonlinear filter, the function expansion
nonlinear filter, in the acoustic echo cancellation - the Volterra filter can be regarded as special case
of the function expansion nonlinear filter. Then by leveraging to a multi-channel configuration of the
function expansion nonlinear filter and the sampling theory for nonlinear systems, we extend linear
sub-band delay-less adaptive filter techniques to develop an efficient sub-band implementation of
the adaptive function expansion nonlinear filter. The developed sub-band configuration of the
adaptive nonlinear filter can greatly improve the convergence rate and reduce the computational
complexity of nonlinear echo cancellers, which is shown by analyses and simulations.

Index Terms
Adaptive nonlinear filter, Adaptive Echo Cancellation, Sub-band implementation.