Patent ID: 6859531
Filing Date: 2005-02-22
Classification: H04M

Abstract:
1. An acoustic echo cancellation system comprising: an adaptive filter to create an echo estimate and an error term that includes a residual echo; a residual echo estimator to independently calculate estimates of a real portion and an imaginary portion of a discrete Fourier transform (DFT) of the residual echo, wherein the residual echo estimator includes: a first input node to receive a composite signal comprising near-end speech, noise, and an echo of far-end speech; a second input node to receive the echo estimate; and a third input node to receive a difference between the echo estimate and the composite signal; and wherein the residual echo estimator is configured to calculate the real and imaginary portions of the DFT of the residual echo using an average of the composite signal and a previous output sample as an estimate of the near-end speech and the noise when both the near-end speech and the far-end speech are active.