Non-linear acoustic echo cancellation using empirical mode decomposition

The increasing popularity of miniature devices and loudspeakers has fuelled research in non-linear acoustic echo cancellation (NAEC). This paper reports a novel approach to NAEC based on empirical mode decomposition (EMD), a recently developed technique in non-linear and non-stationary signal analysis. EMD decomposes any signal into a finite number of time varying sub-band signals termed intrinsic mode functions (IMFs). The new approach to NAEC presented here incorporates this multi-resolution analysis with conventional power filtering to estimate non-linear echo in each IMF. Comparative experiments with a competitive baseline approach to NAEC based on pure power filtering show that the new EMD approach achieves greater non-linear echo reduction and faster convergence.