Cross-correlation based echo canceller controllers
AssigneeMicrosoft Corporation
InventorsAsif Iqbal Mohammad, Jack W. Stokes, III, Steven L. Grant
Life of this patent
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Abstract
Cross-correlation based echo canceller controllers are described herein. By way of example, a system for controlling an echo canceller having one or more adaptive filters can include one or more adaptive filter controllers each corresponding to one of the one or more adaptive filters and each configured to halt adaptation of its corresponding adaptive filter according to the cross-correlation of its corresponding corrupted signal and its corresponding error signal of its corresponding adaptive filter.
Claims18
A system comprising:
- an echo canceller having one or more adaptive filters, each of the one or more adaptive filters configured to receive a corrupted signal and to produce an error signal;
- one or more adaptive filter controllers stored in memory, each corresponding to one of the one or more adaptive filters and each configured to halt adaptation of its corresponding adaptive filter according to a cross-correlation of its corresponding corrupted signal and its corresponding error signal of its corresponding adaptive filter,
- the one or more adaptive filter controllers are configured to employ a decision statistic to halt adaptation of their corresponding adaptive filters, the decision statistic being based in part on a ratio of an estimate of a time domain cross-correlation coefficient between the corrupted signal and the error signal and an estimate of a time domain variance of the corrupted signal.
Computer-executable instructions for performing a method of controlling one or more adaptive filters of an echo canceller, the computer-executable instructions stored on one or more computer-readable media, the method comprising:
- receiving a corrupted signal;
- receiving one or more cancellation errors from the one or more adaptive filters of the echo canceller;
- computing one or more decision statistics based in part on a ratio of an estimate of a time domain cross-correlation of the corrupted signal and the one or more cancellation errors and an estimate of a time domain variance of the corrupted signal;
- comparing the one or more decision statistic to their threshold values;
- and
- controlling the one or more adaptive filters based on the comparison of the one or more decision statistics to their threshold values.
A system for facilitating communication, comprising:
- means for cancelling an echo in a corrupted signal, the means for cancelling the echo comprising one or more adaptive filters stored in memory;
- and
- means for stopping the one or more adaptive filters from adapting based in part on a ratio of an estimate of a time domain cross-correlation of the corrupted signal with a residual signal produced by the means for cancelling the echo and an estimate of a time domain variance of the corrupted signal.
Dependencies are inferred from the claim text.