论文信息 - Echo Canceler with Two Echo Path Models

Echo Canceler with Two Echo Path Models

An adaptive echo canceler with two echo path models is proposed to overcome the false adaptation problem for double-talking. The echo canceler possesses two separate echo path models (EPMs), one (background EPM) for adaptively identifying echo path transfer characteristics and the other (foreground EPM) for synthesizing an echo replica to cancel out echo. The parameter values of the foreground EPM are refreshed by those of the background EPM, according to a transfer control logic, when the logic determines that the background EPM is giving a better approximation of echo path transfer characteristics than the foreground EPM. Completely digital hardware implementation is described. Using the hardware, it is shown that virtually complete double-talking protection is actually realizable by the new method.

[1] A. Sato,et al. Echo-suppressor design for space communication , 1966 .

[2] G. K. Helder,et al. Transmission delay and echo suppression , 1970, IEEE Spectrum.

[3] M. M. Sondhi,et al. An adaptive echo canceller , 1967 .

[4] M. Onufry,et al. Performance of a digital adaptive echo canceller in a simulated satellite circuit environment , 1972 .

[5] K. Nagata,et al. A Blockless Echo Suppressor , 1969 .

[6] G. G. Stokes. "J." , 1890, The New Yale Book of Quotations.

[7] J. R. Rosenberger,et al. Performance of an adaptive echo canceller operating in a noisy, linear, time-invariant environment , 1971 .

[8] G. K. Helder,et al. Customer evaluation of telephone circuits with delay , 1966 .

[9] L. S. Moye,et al. Subjective evaluation of unsuppressed echo in simulated long-delay telephone communications , 1971 .

[10] J. Nagumo,et al. A learning method for system identification , 1967, IEEE Transactions on Automatic Control.

[11] H. R. Rudin,et al. Application of automatic transversal filters to the problem of echo suppression , 1966 .

[12] G. K. Helder,et al. Echo suppressor design in telephone communications , 1963 .

[13] M. Sondhi,et al. A self-adaptive echo canceller , 1966 .

[14] M. Sondhi. Theory and Computer Simulation of a Self‐Adapting Echo Canceler , 1966 .