A gradient-controlled improved proportionate multi-delay filter

As an attractive alternative to time domain solutions, the frequency domain multi-delay filter has gained attention in acoustic echo cancellation (AEC) because of its efficient implementation. This paper proposes a new gradient-controlled improved proportionate multi-delay filter (GC-IPMDF) for AEC. It uses the magnitude of a time-averaging gradient estimate as the step size distribution vector instead of the magnitude of the current coefficients estimate that is used in the existing improved proportionate multi-delay filter (IPMDF). Simulation results demonstrate that it can speed up the convergence process while maintaining the same steady-state error performance as compared with the previously proposed approach.