摘要 |
An echo canceler uses an adaptive filter to remove an echo of a far-end input signal from a near-end input signal. Filter coefficients are calculated and updated while the far-end signal is active. While the far-end signal is silent, substitute filter coefficients are similarly calculated to be swapped in as initial values for the filter coefficients when the far-end signal changes from silent to active. The substitute filter coefficients are generated from a simulated far-end signal and a simulated near-end signal obtained by combining corresponding samples in different intervals of the far-end and near-end input signals. To facilitate convergence of the substitute filter coefficients, use of the simulated far-end and near-end signals is disabled when the corresponding samples cancel out. |