A stereo echo canceler with correct echo-path identification based on an input-sliding technique

A new stereo echo canceler with correct echo-path identification based on an input-sliding technique is proposed. A time-varying filter located in one of the two channels periodically delays the input signal. By this input sliding, the correct echo-path identification is achieved. Aliasing components and audible clicks by input-sliding are made inaudible by selecting appropriate parameter values for the time-varying filter. Simulations with the NLMS algorithm and a white Gaussian signal confirm the correct echo-path identification. The subjective quality of the input signal with slides is 4.38 based on the ITU-R five-grade impairment scale. Experimental results based on an implementation by 32-bit floating-point digital signal processors show that ERLE is not degraded by talker changes in the remote room. The mean opinion score is as much as 0.55-point higher than the conventional stereo echo canceler for different round-trip delays.