Patent ID: 7783032

Claim:
A method of processing subband signals for cancelling an undesired effect on a signal, the method comprising steps of: analysing a primary signal and a reference signal in a time domain each through an oversampled filterbank to produce frequency domain primary signals and frequency domain reference signals in a plurality of subbands, where the primary signal is a desired signal affected by an undesired signal, and the reference signal corresponds to the undesired signal; processing the frequency domain primary signal and the frequency domain reference signal using an adaptive filter in the processing in each subband, comprising: filtering at the adaptive filter the frequency domain reference signal in each subband; adding the filtered frequency domain reference signal and the frequency domain primary signal in each subband to output a subband signal in each subband; and operating on the frequency domain primary signal and the frequency domain reference signal in each subband to improve the convergence of the adaptive filter in each subband; and synthesizing the subband signals with an oversampled synthesis filterbank to output a time domain signal in which the subband processing has cancelled the effect of the undesired signal, the operating step including, in each subband: whitening the frequency domain primary signal; whitening the frequency domain reference signal; and adjusting coefficients of the adaptive filter based on the whitened frequency domain primary signal and the whitened frequency domain reference signal.