Patent ID: 6865270

Claim:
A high gain, fast convergence far end echo cancellation system for reducing far end echo in an echo path, comprising: an adaptation processor for generating substantially real time filter coefficients; a primary static filter for storing an original set of filter coefficients and for generating a primary echo correcting signal; a secondary static filter for temporarily storing a recent set of adaptation constants; a high gain adapted filter for storing a real time set of filter coefficients and generating a real time echo correcting signal; first comparison means for generating a first error signal indicative of a degree of echo cancellation resulting from summation of the primary echo correcting signal and a far end echo containing signal; second comparison means for generating a second error signal indicative of a degree of echo cancellation resulting from summation of the real time echo correcting signal and the far end echo signal; and, transfer control logic means, cooperatively interconnected with the primary static, secondary static and adapted filters, and with the first and second comparison means, for comparing the error signals over a preselected time interval and for replacing the original filter coefficients with the recent filter coefficients and the recent filter coefficients with the real time filter coefficients only if the error signals are converging, whereby the system substantially ignores temporally transient and large amplitude near end noise in the echo path.