APPARATUS FOR CANCELING DETECTION DELAY OF END POINT OF DOUBLE-TALK INTERVAL IN DOUBLE-TALK DETECTOR FOR ACOUSTIC ECHO CANCEL, AND METHOD THEREFOR

摘要

PURPOSE: An apparatus for canceling the detection delay of an end point of a double-talk interval and a method therefor are provided to efficiently cancel an echo although an impulse response of an echo path is changed in a point in which a double-talk is ended by detecting the double-talk interval, periodically estimating a power of a signal, and reducing the detection delay of the end point of the double-talk interval. CONSTITUTION: An echo signal estimating unit(21) estimates an echo signal from a reference input signal and a previous residual error signal through an adaptive filtering. A residual error signal generating unit(22) subtracts the estimated echo signal from an expected signal and generates a residual error signal. A power and correlation degree estimation calculating unit(23) estimates and calculates a power of the expected signal, a power of the residual error signal, and a correlation degree between the expected signal and the residual error signal using a forgetting index from the residual error signal and the expected signal generated in the residual error signal generating unit(22). A cross correlation coefficient calculating unit(24) calculates a cross correlation coefficient between the expected signal and the residual error signal using the power of the expected signal, the power of the residual error signal, and the correlation degree calculated in the power and correlation degree estimation calculating unit(23). A cross correlation coefficient comparing unit(25) compares the cross correlation coefficient calculated in the cross correlation coefficient calculating unit(24) with a predetermined threshold value and outputs confirmation information about a double talk interval. An adaptive filter coefficient updating unit(26) updates a coefficient by the adaptive filtering on the basis of confirmation information of a single-talk interval output from the cross correlation coefficient comparing unit(25). A power estimating unit(27) estimates a power on the basis of the double-talk interval output from the cross correlation coefficient comparing unit(25).