Method and apparatus for analyzing a return signal and adaptive echo canceller using the same

摘要

The method involves inputting a signal (Sd) to an FIR linear prediction filter (21) to produce a direct return signal (e) of minimal energy. The return signal is input to an FIR filter (24) with the same coefficients as the linear filter to produce a second signal (g). The amount of energy contained in the first and second signals is calculated (T,E). If the return signal contains components other than echo components the sum is compared to a detection threshold. An adaptive filter can be applied to the input signal to reduce the echo response.