In order the system and the mannered null adaptation filter in order to evade the error convergence which originates in the existence of tone at the time of

摘要

PROBLEM TO BE SOLVED: To provide a system and method for avoiding a false convergence caused by a presence of tones in a time-domain echo cancellation process.;SOLUTION: The system avoids the false convergence in an echo canceller, having an adaptation step size controlled to allow a set of filter tap values to converge and having an adaptive filter to estimate a channel response over a whole operation frequency range. The system comprises a means for determining a spectral content of the set of filter tap values and a means for controlling the adaptation step size of the adaptive filter in response to the spectral content of the set of filter tap values. A means for controlling the adaptation step size comprises a means for reducing the adaptation step size if the spectral content indicates a condition which may cause the false convergence and a means for increasing the adaptation step size subsequent to reduce the adaptation step size.;COPYRIGHT: (C)2005,JPO&NCIPI