Frequency selective step-size control for acoustic echo cancellation

A new algorithm to control the step-size of a frequency domain echo cancellation system is presented. The step-size is controlled via the estimate of the coherence between the microphone signal and the output of the echo cancellation filter. The use of coherence allows an independent step-size control for each frequency bin. Additive local noise correlated with the echo signal and thus corrupting the adaption is monitored by the coherence and the step-size for the adaption is set correspondingly. The algorithm allows better convergence than conventional algorithms due to its frequency selectivity and does not require any a-priori knowledge.