Patent ID: 7508931
Filing Date: 2009-03-24
Classification: H04B

Abstract:
1. A method of detecting an echo path chance in an echo canceller having an adaptive filter, comprising: a) initializing an Echo Path Change Counter; b) monitoring signal and performance information from said echo canceller indicative of one of either echo canceller convergence or divergence; c) decrementing said Echo Path Change Counter based on an indication of echo canceller convergence; d) incrementing said Echo Path Change Counter in response to an indication of echo canceller divergence; and e) indicating said echo Path change in the event said Echo Path Change Counter exceeds a predetermined threshold wherein said monitoring of said signal and performance information includes determining whether ERLE is greater than a minimum expected ERLE value (Expected ERLE) and input signal energies (Rin and Sin) are greater than their respective noise levels, in which case an indication of strong convergence is provided whereupon said Echo Path Change Counter is decremented using a fast decrement.