Fast echo canceller training based on circular convolution technique

Abstract

For full-duplex high-speed data communication over the two-wire telephone line, sufficient suppression of the echo is required, which may require a long training time. Fast training can be achieved by initializing the coefficients of the echo canceller with an estimate of the impulse response of the echo path. We propose a fast initialization method for the echo canceller by employing a circular convolution technique. The proposed method enables the use of real-valued training signals instead of complex-valued ones, resulting in significant reduction of the initialization time as well as of the implementation complexity. Finally, the performance of the proposed method is analyzed and verified by experiments.