Hybrid echo canceller controllers
Hybrid echo canceller controllers are described herein. By way of example, a system for controlling an echo canceller can include a signal indicator and an echo canceller controller. The signal indicator can be configured to indicate periods of near-end signal and to indicate periods of echo only with echo-path change in the corrupted signal based at least in part on cross-correlation between two signals associated with the echo canceller. The echo canceller controller can be configured to control the echo canceller according to indications from the signal indicator.
1. A system for controlling an echo canceller configured to remove echo from a corrupted signal, comprising:
a signal indicator configured to indicate periods of near-end signal and to indicate periods of echo only with echo-path change in the corrupted signal based at least in part on a cross-correlation between two signals associated with the echo canceller; and
an echo canceller controller configured to control the echo canceller according to indications from the signal indicator, wherein the signal indicator comprises one or more signal discriminators configured to determine a relative influence of the near-end signal compared to the echo in the corrupted signal, wherein
the echo canceller controller is configured to control the echo canceller according to indications from the signal indicator by preventing at least one of the echo canceller's one or more adaptive filters from adapting when the signal indicator indicates a period of near-end signal in the corrupted signal;
the signal indicator is further configured to indicate periods of no near-end signal and no echo and periods of echo only without echo-path change in the corrupted signal;
the echo canceller controller is configured to control the echo canceller according to the indications from the signal indicator by preventing at least one of the echo canceller's one or more adaptive filters from adapting when the signal indicator indicates a period of no near-end signal and no echo in the corrupted signal and by allowing at least one of the echo canceller's one or more adaptive filters to adapt when the signal indicator indicates a period of echo only without echo-path change or a period of echo only with echo-path change in the corrupted signal;
the signal indicator comprises one or more cross-correlators configured to cross-correlate the corrupted signal with the echo canceller's error signal, and one or more detectors configured to facilitate indicating periods of no echo and no near-end signal in the corrupted signal; and
the one or more cross-correlators are implemented at a frequency bin level and the one or more signal discriminators comprise one signal discriminator configured at the frame level and the one or more detectors comprise one detector configured at the frame level.
2. The system of claim 1 , wherein the echo canceller controller is configured to control the echo canceller according to the indications from the signal indicator by accelerating adaptation of at least one of the echo canceller's adaptive filters when the signal indicator indicates a period of echo only with echo-path change in the corrupted signal.
3. The system of claim 1 , wherein the echo canceller controller is configured to control the echo canceller according to the indications from the signal indicator by switching to another echo canceller algorithm when the signal indicator indicates a period of echo only with echo-path change in the corrupted signal.
4. The system of claim 1 , wherein the one or more signal discriminators and the one or more detectors are implemented by real time recurrent learning networks.
5. The system of claim 1 , wherein the cross-correlation is between the corrupted signal and the echo canceller's error signal.
6. The system of claim 1 , wherein the signal indicator comprises at least two cross-correlators that are configured to cross-correlate at least one different signal associated with the echo canceller.
7. The system of claim 6 , wherein the signal indicator is implemented in the frequency domain.
8. The system of claim 1 , wherein the echo canceller controller comprises an overall decision statistic.
9. A system for controlling an echo canceller configured to remove echo from a corrupted signal, comprising:
a signal indicator configured to indicate periods of near-end signal and to indicate periods of echo only with echo-path change in the corrupted signal based at least in part on a cross-correlation between two signals associated with the echo canceller, the signal indicator further configured to indicate periods of no near-end signal and no echo and periods of echo only without echo-path change in the corrupted signal, wherein the signal indicator comprises:
one or more signal discriminators configured to determine a relative influence of the near-end signal compared to the echo in the corrupted signal;
one or more detectors configured to facilitate indicating periods of no echo and no near-end signal in the corrupted signal;
one or more cross-correlators configured to cross-correlate the corrupted signal with the echo canceller's error signal, wherein the one or more signal discriminators and the one or more detectors are implemented by real time recurrent learning networks; and
an echo canceller controller configured to control the echo canceller according to indications from the signal indicator by
preventing at least one of the echo canceller's one or more adaptive filters from adapting when the signal indicator indicates a period of near-end signal in the corrupted signal;
preventing at least one of the echo canceller's one or more adaptive filters from adapting when the signal indicator indicates a period of no near-end signal and no echo in the corrupted signal; and
allowing at least one of the echo canceller's one or more adaptive filters to adapt when the signal indicator indicates a period of echo only without echo-path change or a period of echo only with echo-path change in the corrupted signal.
10. The system of claim 9 , wherein the echo canceller controller is further configured to control the echo canceller according to the indications from the signal indicator by accelerating adaptation of at least one of the echo canceller's adaptive filters when the signal indicator indicates a period of echo only with echo-path change in the corrupted signal.
11. The system of claim 9 , wherein the echo canceller controller is further configured to control the echo canceller according to the indications from the signal indicator by switching to another echo canceller algorithm when the signal indicator indicates a period of echo only with echo-path change in the corrupted signal.
12. The system of claim 9 , wherein the one or more cross-correlators is implemented at a frequency bin level and the one or more signal discriminators comprise one signal discriminator configured at the frame level and the one or more detectors comprise one detector configured at the frame level.
13. The system of claim 9 , wherein the cross-correlation is between the corrupted signal and the echo canceller's error signal.
14. The system of claim 9 , wherein the signal indicator comprises at least two cross-correlators that are configured to cross-correlate at least one different signal associated with the echo canceller.
15. The system of claim 14 , wherein the signal indicator is implemented in the frequency domain.
16. The system of claim 9 , wherein the echo canceller controller comprises an overall decision statistic.
17. A system for controlling an echo canceller configured to remove echo from a corrupted signal, comprising:
a signal indicator configured to indicate periods of near-end signal and to indicate periods of echo only with echo-path change in the corrupted signal based at least in part on a cross-correlation between two signals associated with the echo canceller, the signal indicator further configured to indicate periods of no near-end signal and no echo and periods of echo only without echo-path change in the corrupted signal, the signal indicator comprising:
one or more signal discriminators configured to determine a relative influence of the near-end signal compared to the echo in the corrupted signal, the one or more signal discriminators comprising one signal discriminator configured at the frame level;
one or more detectors configured to facilitate indicating periods of no echo and no near-end signal in the corrupted signal, the one or more detectors comprising one detector configured at the frame level; and
one or more cross-correlators configured to cross-correlate the corrupted signal with the echo canceller's error signal, the one or more cross-correlators being implemented at a frequency bin level, wherein the one or more signal discriminators and the one or more detectors being implemented by real time recurrent learning networks; and
an echo canceller controller configured to control the echo canceller according to indications from the signal indicator by
preventing at least one of the echo canceller's one or more adaptive filters from adapting when the signal indicator indicates a period of near-end signal in the corrupted signal;
preventing at least one of the echo canceller's one or more adaptive filters from adapting when the signal indicator indicates a period of no near-end signal and no echo in the corrupted signal; and
allowing at least one of the echo canceller's one or more adaptive filters to adapt when the signal indicator indicates a period of echo only without echo-path change or a period of echo only with echo-path change in the corrupted signal.