SPECTRAL NOISE COMPENSATION FOR ECHO CANCELLATION

摘要

An echo canceller (10) includes an analysis filter bank (24) for dividing a send-input signal (SI) and a receive-input signal (RI) into subband send-input signals (SC1-SC16) and subband receive signals (RC1-RC16). Each of the subband receive signals (RC1-RC16) is convolved with an impulse response function pertaining the echo path coupling the receive signal to the send-input signal within each subband, yielding estimated echo signals (EC1-EC16), which are then each subtracted from the corresponding subband send-input signal, to produce error signals (ER1-ER16). Residual echo components within the error signals are attenuated by a variable attenuator (36a-p), and a choice component is injected into each attenuated error signal to compensate for attenuation of background noise incidental to the variable attenuation of the error signals.