System and method for 2-channel and 3-channel acoustic echo cancellation
View Patent ↗Systems and methods for providing acoustic echo cancellation are provided. Primary and secondary acoustic signals are received by a communication device. The acoustic signals may include loudspeaker leakage. A null coefficient is then adaptively determined for each subband of the secondary acoustic signal. The null coefficient is applied to the secondary acoustic signal to generate a coefficient-modified signal. The coefficient-modified signal is subtracted from the primary acoustic signal to generate a masked acoustic signal with reduced or no echo. The masked acoustic signal may be output.
1. A method for providing acoustic echo cancellation, comprising:
receiving a primary and secondary acoustic signal at a communication device;
adaptively determining a null coefficient for each subband of the secondary acoustic signal;
applying the null coefficient for each subband of the secondary acoustic signal to a respective subband of the secondary acoustic signal to generate a coefficient-modified signal;
subtracting the coefficient-modified signal from the primary acoustic signal to generate a masked acoustic signal; and
outputting the masked acoustic signal.
2. The method of claim 1 further comprising converting the masked acoustic signal into time domain for outputting.
3. The method of claim 1 further comprising applying a noise suppression mask to the primary acoustic signal.
4. The method of claim 3 wherein adaptively determining the null coefficient is represented by
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5. The method of claim 1 wherein adaptively determining the null coefficient comprises applying at least one adaptation constraint.
6. The method of claim 5 wherein the at least one adaptation constraint comprises a frequency range constraint.
7. The method of claim 5 wherein the at least one adaptation constraint comprises a far-end signal energy constraint.
8. The method of claim 1 further comprising calibrating the communication device.
9. The method of claim 1 further comprising determining a far-end energy signal.
10. The method of claim 9 further comprising delaying the far-end energy signal.
11. The method of claim 1 further comprising providing a switch, the switch allowing selective implementation of the acoustic echo cancellation in a noise suppression system.
12. A system for providing acoustic echo cancellation in a communication device, comprising:
an acoustic sensor configured to receive a primary acoustic signal and a secondary acoustic signal;
a null module configured to adaptively determine a null coefficient for each subband of the secondary acoustic signal and apply the null coefficient for each subband of the secondary acoustic signal to a respective subband of the secondary acoustic signal to generate a coefficient-modified signal; and
an adder configured to subtract the coefficient-modified signal from the primary acoustic signal to generate a masked acoustic signal.
13. The system of claim 12 further comprising a frequency synthesis module configured to convert the masked acoustic signal into time domain for outputting.
14. The system of claim 12 further comprising a noise suppression system configured to reduce near-end noise from the primary acoustic signal.
15. The system of claim 12 , wherein the null module configured to adaptively determine the null coefficient comprises the null module configured to adaptively determine the null coefficient represented by
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16. The system of claim 12 wherein the null module is further configured to calibrate the communication device.
17. The system of claim 12 further comprising a weighted energy module configured to determine a far-end energy signal.
18. The system of claim 17 further comprising a delay module configured to delay the far-end energy signal.
19. The system of claim 17 further comprising a switch configured to allow selective implementation of the acoustic echo cancellation in a noise suppression system.
20. A non-transitory machine readable medium having embodied thereon a program, the program providing instructions for a method for acoustic echo cancellation, the method comprising:
receiving a primary and secondary acoustic signal at a communication device;
adaptively determining a null coefficient for each subband of the secondary acoustic signal;
applying the null coefficient for each subband of the secondary acoustic signal to a respective subband of the secondary acoustic signal to generate a coefficient-modified signal;
subtracting the coefficient-modified signal from the primary acoustic signal to generate a masked acoustic signal; and
outputting the masked acoustic signal.