Higher-order time-varying allpass filters for signal decorrelation in stereophonic acoustic echo cancellation
A new technique is presented for decorrelating the input signals in stereophonic systems by means of time-varying allpass filters. The controllable and almost linear phase response of higher-order allpass filters is exploited in this context and a particular type of time variation is used to vary the parameters of such filters. Simulation results are presented based on real stereophonic signals and supported by subjective listening tests.