Device and method for stereo noise cancellation

1. A noise cancellation method, comprising:

updating a first far-end channel filter according to a first variance yielded based on an input signal and a first far-end signal included in the input signal;

providing a first output signal obtained by removing a first far-end noise signal from the input signal through the first far-end channel filter;

updating a second far-end channel filter according to a second variance yielded based on the first output signal and a second far-end signal included in the input signal; and

providing a second output signal obtained by removing a second far-end noise signal from the first output signal through the second far-end channel filter, wherein updating the first far-end channel filter includes estimating the first variance based on the input signal and the first far-end signal and creating a first cross-correlation vector and a first autocorrelation matrix based on the first variance.

2. The noise cancellation method of claim 1 , wherein an initial value of the first variance is obtained by cross correlation between the input signal and the first far-end signal and autocorrelation of the first far-end signal.

3. The noise cancellation method of claim 1 , wherein the first cross-correlation vector and the first autocorrelation matrix are updated according to the first variance.

4. The noise cancellation method of claim 1 , wherein the first far-end channel filter is updated according to the first cross-correlation vector and the first autocorrelation matrix.

5. The noise cancellation method of claim 1 , further comprising:

initializing the first variance; and

initializing the second variance.

6. The noise cancellation method of claim 5 , wherein the first far-end channel filter is updated according to a first cross-correlation vector and a first autocorrelation matrix obtained based on the first variance.

7. A noise cancellation method, comprising:

updating a first far-end channel filter according to a first variance yielded based on an input signal and a first far-end signal included in the input signal;

providing a first output signal obtained by removing a first far-end noise signal from the input signal through the first far-end channel filter;

updating a second far-end channel filter according to a second variance yielded based on the first output signal and a second far-end signal included in the input signal; and

providing a second output signal obtained by removing a second far-end noise signal from the first output signal through the second far-end channel filter, wherein updating the second far-end channel filter includes estimating the second variance based on the first output signal and the second far-end signal and creating a cross-correlation vector and an autocorrelation matrix based on the second variance.

8. The noise cancellation method of claim 7 , wherein an initial value of the second variance is obtained by cross correlation between the output signal and the second far-end signal and autocorrelation of the second far-end signal.

9. The noise cancellation method of claim 7 , wherein the second cross-correlation vector and the second autocorrelation matrix are updated according to the second variance.

10. The noise cancellation method of claim 9 , wherein the second far-end channel filter is updated according to the second cross-correlation vector and the second autocorrelation matrix.

11. A noise cancellation method, comprising:

providing a first estimated output signal based on a first prior far-end channel filter corresponding to a prior frame, an input signal, and a first far-end signal;

updating a first current far-end channel filter corresponding to a current frame according to the first estimated output signal and the first prior far-end channel filter;

providing a first output signal obtained by removing a first far-end noise signal from the input signal using the first current far-end channel filter;

providing a second estimated output signal based on a second prior far-end channel filter corresponding to the prior frame, the first output signal, and a second far-end signal;

updating the second current far-end channel filter corresponding to the current frame according to the second estimated output signal and the second prior far-end channel filter; and

providing a second output signal obtained by removing a second far-end noise signal from the first output signal using the second current far-end channel filter, wherein updating the first current far-end channel filter includes estimating a first variance based on the first estimated output signal and creating a first inverse autocorrelation matrix based on the first variance.

12. The noise cancellation method of claim 11 , wherein the first variance is determined by the first estimated output signal provided based on the first prior far-end channel filter.

13. The noise cancellation method of claim 12 , wherein the first variance is determined by the product of a first weight and the square of the absolute value of the first estimated output signal.

14. The noise cancellation method of claim 13 , wherein the first current far-end channel filter converges to a constant value.

15. The noise cancellation method of claim 11 , wherein updating the second current far-end channel filter includes estimating a second variance based on the second estimated output signal and creating a second inverse autocorrelation matrix based on the second variance.

16. The noise cancellation method of claim 15 , wherein the second variance is determined by the second estimated output signal provided based on the second prior far-end channel filter.

17. The noise cancellation method of claim 16 , wherein the second variance is determined by the product of a second weight and the square of the absolute value of the second estimated output signal.