Patent ID: 6185299
Filing Date: 2001-02-06
Classification: H04M

Abstract:
A method for adaptive echo cancellation in a voice communication system comprising the steps of:transmitting a reference signal x over the system from a transmitting device;removing any echo signal from a primary signal d received by said transmitting device, said echo signal being sent back by said voice communication system in answer to said reference signal x, using an adaptive filter having a plurality of coefficients the value of which at each time n being computed from the value of the same coefficient at time n-1 modified by a normalization factor depending upon the energy of said reference signal d in that said normalization factor is the maximum value between a first value representing the energy of said reference signal at time n and a second value depending on a value of said normalization factor previously stored during a preceding predetermined interval time multiplied by an attenuation factor less than 1.