An adaptive delay filter with varibale gains and variable taps

Abstract

In this paper we extend our work on a new type of adaptive filter called an adaptive delay filter. This filter structure includes variable delay taps in addition to the variable gains. The adaptive delay filter is especially applicable to system modelling problems in which the system to be modelled has a sparse impulse response. Using the standard adaptive filter could require very large filters, while an adaptive delay filter could model the sparse impulse response with very few elements in the filter since the delay taps spread out to adapt to the unknown system. Our previous work presented an algorithm for adapting the delay taps while keeping the gains constant. We now present results of combining an algorithm for adapting the delay taps with an algorithm for adapting the gains. An analysis of the corresponding mean squared error surface is included, along with simulation results of the adaptive delay filter's performance in modelling both the delay taps and the gains of an unknown sparse system.