【発明の名称】改良型非線形エコー経路検出を有するデュアルHアーキテクチャを利用するエコーキャンセラ

Japanese Patent JP2001523925

A

An echo canceller circuit for use in an echo canceller system is set forth that provides sensitive non-linear echo path response detection. The echo canceller circuit comprises a first digital filter having non-adaptive tap coefficients to simulate an echo response occurring during a call. A second digital filter having adaptive tap coefficients to simulate an echo response occurring during the call is also used. The adaptive tap coefficients of the second digital filter are updated over the duration of the call. A coefficient transfer controller is disposed in the echo canceller circuit to transfer the adaptive tap coefficients of the second digital filter to replace the tap coefficients of the first digital filter when a set of one or more transfer conditions is met. A non-linear echo path response detector is provided. The non-linear echo path detector is responsive to one or more parameters of the first and second digital filters to detect a non-linear echo path condition. In accordance with one embodiment of the present invention, the non-linear echo path detector is responsive to a transfer density value corresponding to a number of transfers executed by the coefficient transfer controller. In accordance with a further embodiment of the present invention, the non-linear echo path detector is responsive to a coefficient time dispersion characteristic of the second digital filter for detecting a non-linear echo path condition.

Rubber Tewks, Kenneth Pee.

JP2000521639A

November 27, 2001

November 13, 1998

Click for automatic bibliography generation  

Tellabs Operations, Incorporated

H03H21/00; H04B3/23; H04M1/58; H04M9/08; (IPC1-7): H04B3/23; H03H21/00; H04M1/58; H04M9/08

Takashi Ishida (4 others)

Previous Patent: 改良型係数転送を有するデュアルＨアーキテクチャを利用するエコーキャ�...

Next Patent: 改良型ダブルトーク検出を有するデュアルＨアーキテクチャを利用するエ�...