Patent ID: 9613634
Date: 2017-04-04
CPC Classifications: G10K,G10L,H04M

Claim:
1. A method for cancelling or reducing acoustic echoes in speech or audio signal enhancement processing, the method comprising: using a received reference signal (a received Rx signal) to excite an adaptive filter wherein the output of the adaptive filter forms a replica signal of acoustic echo if the adaptive filter is performed in time domain, or the output of the adaptive filter forms replica frequency domain coefficients of acoustic echo if the adaptive filter is performed in frequency domain; controlling an adaptation step size for updating the coefficients of the adaptive filter by using both open-loop parameters and closed-loop parameters, wherein the adaptation step size reflects a new percentage amount added into the updated coefficients of the adaptive filter during each updating step, one of the most important open-loop parameters is an energy ratio between an energy of a returned echo signal in an input microphone signal (an input Tx signal) and an energy of the received reference signal, and one of the most important closed-loop parameters is a normalized correlation or a square of the normalized correlation between the input microphone signal and the replica signal of acoustic echo if in the time domain or between the frequency domain coefficients of the input microphone signal and the replica frequency domain coefficients of acoustic echo if in the frequency domain; subtracting the replica signal or frequency domain coefficients of acoustic echo from the microphone input signal in the time domain or the frequency domain to suppress the acoustic echo in the microphone input signal.