Echo canceller to take advantage of dual H architecture with an improved nonlinear echo path detection

摘要

Is shown to (25) echo canceller circuit that is used to provide (57) [summary] high sensitivity non-linear echo path response detection (300), in the echo canceller system. Echo canceller circuit (25) includes a first digital filter with a non-adaptive tap coefficients to simulate the echo response that occurs during a call (35). It is used the second digital filter with adaptive tap coefficients to simulate the echo response that occurs during a call also (30). Adaptive tap coefficients of the second digital filter is updated throughout the duration of the call. Transfer the adaptive tap coefficients of the second digital filter when the coefficient transfer controller is disposed echo canceller circuit (25), a set of transfer conditions more are met whether one, tap coefficients of the first digital filter I want to replace. Linear echo path response detector (300) is provided. Nonlinear echo path detector detects the non-linear path conditions in response to a parameter of whether one or more of the second digital filter and a first. According to one embodiment of the present invention, the non-linear echo path detector (300) is responsive to the transition density value corresponding to the number of transfer which is executed coefficient transfer control device (65). According to yet another embodiment of the present invention, in order to detect a non-linear path conditions, non-linear echo path detector (300) is responsive to a coefficient times the dispersion characteristics of the second digital filter.