Patent ID: 7672445
Filing Date: 2010-03-02
Classification: H04M

Abstract:
1. An echo cancellation system comprising: an echo canceller unit operative to receive a reference signal and a near-end signal, derive an echo estimate signal based on the reference and near-end signals, cancel a portion of echo in the near-end signal based on the echo estimate signal, and provide the echo estimate signal and a first intermediate signal having residual echo not canceled by the echo canceller unit; a detection unit operative to detect for large nonlinear echo based on the echo estimate signal and to provide a detection signal indicating whether large nonlinear echo is detected; and an echo suppression unit operative to suppress large nonlinear echo in the first intermediate signal in accordance with the detection signal and to provide a second intermediate signal containing at least a portion of the first intermediate signal and having at least a portion of the large nonlinear echo suppressed, wherein the echo suppression unit derives a variable gain based on the detection signal and suppresses the large nonlinear echo in the first intermediate signal based on the variable gain.