Patent ID: 6999582
Filing Date: 2006-02-14
Classification: H04M

Abstract:
1. A method of suppressing echo signals generated in a communication path comprising the steps of: monitoring signals supplied to said communication path to generate an envelope of the power level of said monitored signals using an infinite impulse response filter, said IIR lowpass filter generating said envelope by solving the equation: where alpha is a parameter of said IIR filter, Y is the power level of the current monitored signal, Y 0 is the power level of a previous monitored signal and AbsY and AbsY 0 are the absolute values of the power levels Y and Y 0 respectively; calculating an echo signal level by solving the equation: where A is the minimum attenuation of echo signals in said communication path, said echo signal level being used to select a mask in the form of a string of n-bits, at least the most significant bits having a zero value; and masking digitized signals received from said communication path with said selected mask.