ECHO CANCELER AND ECHO PATH ESTIMATING METHOD

摘要

An echo canceler which can perform the training of echo path estimation without causing any hindrance to calls. The echo canceler is equipped with a pseudo-noise generating section which generates specific training signals (pseudo-noise) which is forcedly supplied to a transmission line for transmitting the voice of a far-end talker. When the transmission level of the far-end talker is very low or when no voice is transmitted, a certain correlation is established between the pseudo-noise and the signal of the transmission line. Based on such a correlation, coefficients for generating a pseudo-echo are calculated. Therefore, the training of echo path estimation is performed based on the pseudo-noise without using the voice of the far-end talker, and an adequate pseudo-echo is produced. <IMAGE>