An echo canceller comprising a first wavelet decomposition block for decomposing a reference signal into a plurality of reference wavelet packets ; a second wavelet decomposition block for decomposing an echo signal into a plurality of echo signal packets; an adaptive filter bank for receiving and filtering the refe rence wavelet packets and in response generating a plurality of filtered output pa ckets replicating the echo signal packets; a plurality of subtracters for receivin g and subtracting respective ones of the filtered output packets from the echo sig nal packets and in response generating and applying a plurality of error signals to the adaptive filter bank for modifying the transfer function of the adaptive filter bank; and a wavelet reconstruction block for receiving and reconstructing the error sign als to form a residual signal from which the echo signal has been cancelled. Optimu m wavelet filters for the best echo cancellation are provided, as are two wave let echo cancellation structures.
SUB-BAND ECHO CANCELLER USING OPTIMUM WAVELET PACKETS AND CROSS-BAND CANCELLATION