System and method for 2-channel and 3-channel acoustic echo cancellation

• US 8,259,926 B1
• Filed: 12/21/2007
• Issued: 09/04/2012
• Est. Priority Date: 02/23/2007
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Audience Corporation
• Inventors: Avendano, Carlos, Solbach, Ludger
• Primary Examiner(s): Jamal, Alexander
• Application Number:
  US12/004,899
• Time in Patent Office: 1,719 Days
• Field of Search: 379/406.02, 379/406.03
• US Class Current: 379/406.02
• CPC Class Codes: H04M 9/082 using echo cancellers echo cancellers per se H04B3/23

Abstract

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.

Claims

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

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

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.