The processes of determining a measure of quality representing the performance of a filter in a device for echo cancellation and echo cancellation adaptive filter adaptive dual

摘要

In a dual filter echo cancellation method, a new quality measure provides the basis for a new filter selection and transfer method. The quality measure represents the performance of a filter in the adaptive echo canceller. According to the method, a correlation measure between an echo containing signal and an echo estimation signal produced by the filter is estimated. A power measure of a residual signal, formed by the difference between the echo estimation signal and the echo containing signal, is estimated. The quality measure is calculated by dividing the estimated correlation measure by the estimated power measure. An adaptive filter and a programmable filter are used in the echo cancellation and the quality measures for both are calculated and compared. The best of the two filters, as determined by the quality measure, is used for modeling the echo path, and its filter coefficients are copied to the other filter.