Echo cancellation method and echo canceller implementing such a process

Abstract From the Canadian patent

A reception signal (x(n)) is input to an echo generator system (1). An observation signal (z(n)) is gathered from the system. The reception signal is filtered to produce an echo prediction signal (y(n)). The echo prediction signal is subtracted from the observation signal to produce an error signal (e(n)). The observation signal (z(n)) is decomposed into M spectral components relating to different frequencies of the spectrum. M corresponding spectral components of the echo prediction signal (y(n)) are obtained. M quantities each having a, value with progressive variation representative of a degree of similitude between, respectively one of the M, spectral components of the observation …