Filter bank design for delayless subband adaptive filtering structures with subband weight transformation

Subband adaptive filters have been proposed to avoid the drawbacks of slow convergence and high computational complexity associated with time domain adaptive filters. Subband processing introduces transmission delays and signal degradations due to aliasing effects. In order to overcome the delays, delayless adaptive filtering has been introduced where the adaptive algorithm is working in subbands while the signal filtering is performed in fullband. A design method for filter banks with any oversampling factor is utilized, where the total filter bank group delay may be specified, and where the aliasing and magnitude/phase distortions are minimized. This paper investigates the performance of the filter banks in delayless adaptive filtering applied in an acoustic echo cancellation scenario for telephony conferencing.