An Oversampled Subband Adaptive Filter Without Cross Adaptive Filters

Recently a new real-valued oversampled filter bank has been proposed which reduces the "inband" alias. The filterbank consists of at least three channels which are subsampled by different subsampling ratios. In this paper we investigate into the applicability of this filterbank for adaptive subband filtering and compare the setup with existing subband and fullband techniques. 1. INTRODUCTION One of the main problems in acoustic echo cancelation is the long duration of the impulse response of the echo path which can require adaptive filters with up to several thousand taps to give a good echo reduction. Adaptive filters of such high orders are difficult to implement due to their computational complexity and furthermore they exhibit slow convergence and a high minimum mean squared error which is emphasized by the colored and time varying nature of the input signal in this type of application. One approach to solve these problems is to use subband architectures in conjunction with adapt..