ECHO CANCELLING METHOD, ECHO CANCELLING DEVICE AND PROGRAM

摘要

PROBLEM TO BE SOLVED: To provide an echo cancelling device exhibiting a high-level echo cancellation performance even if a clipping distortion occurs on the sound collection side.

SOLUTION: A clipping restoration part makes a clipped sample of a digital collection signal sample pass through a low-pass filter of which the value being zero ("0") at a position corresponding to the sample, the low-pass filter whose pass-band is a half of Nyquist frequency of an AD converter, to thereby generate a restored sample; and a sound collection-side frequency domain conversion part converts a restored signal sample into a frequency domain restored signal sample of a frequency domain. A difference signal generation part generates a difference signal produced by subtracting a pseudo echo signal from the frequency domain restored signal sample; and a receiving-side frequency domain conversion part converts a received signal input to a receiving end and reproduced by a speaker into a frequency domain reception signal of the frequency domain. An adaptive filter part receives, as input, the difference signal and the frequency domain reception signal and generates a pseudo echo signal therefrom. A temporal domain conversion part converts the difference signal into a signal of a temporal domain to output it to a transmission terminal.

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