Low complexity network echo cancellation system using GSFAP algorithm

In packet-switching digital transmission system, many adaptive echo cancellation algorithms can not be achieved real-time. A low complexity network echo canceller structure is proposed using Gauss-seidle fast affine projection algorithm. An algorithm delay estimator is presented to reduce the adaptive filter order and a nonlinear processor employed to eliminate the residual echo level. Finally, the proposed structure is realized in digital telephone system. Test was made using CSS signal and real speech signal. Test results showed that the improved NEC structure reduced computational complexity effectively and its properties were in line with ITTJ-TG. 168 standards. It is an effective network echo cancellation system.