Performance analysis of adaptive filter structures based on subband decomposition

Abstract

The properties of adaptive finite impulse response (FIR) filters in subbands are investigated, where the input signal is first decomposed in subband signals which are then modified at a lower rate by shorter adaptive filters. Two structures, with different coefficient adaptations, are studied. Expressions for the errors introduced by the nonideal characteristics of the filter banks are found, and a method for the optimal design of the analysis and synthesis banks for the adaptive filtering context is presented. The effect of the non-ideal filter bank characteristics in the adaptation speed of the multirate structures is investigated. The results of computer simulations considering an acoustic echo canceller application are presented.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>