Method for hardware reduction in echo canceller and near-end crosstalk canceller
The present invention provides a method for hardware reduction in the echo canceller and the near-end crosstalk canceller. The method applies an N (N is a positive integer) times divide frequency sampling operation onto the input data list of the echo canceller first (and the near-end crosstalk canceller). Then, it applies an N times multiply frequency sampling operation onto the output data list of the echo canceller (and the near-end crosstalk canceller) to generate a multiplied frequency data list. Afterwards, a low pass filter operation is applied to the multiplied frequency data list to generate a low pass data list to eliminate the echo signal (and the near-end crosstalk signal). The present invention reduces the number of the taps in the echo canceller and the near-end crosstalk canceller by using the digital signal process technique. Therefore, the area of the whole communication IC occupied by the echo canceller and the near-end crosstalk canceller can be reduced.
1. A method for hardware reduction in an echo canceller, comprising:
applying an N (N is a positive integer) times divide frequency sampling operation onto an input data list of the echo canceller, and the frequency-divided input data list is then transmitted to the echo canceller for performing an echo signal cancellation operation on the frequency-divided input data list;
applying an N times multiply frequency sampling operation onto an output data list of the echo canceller to generate a multiplied frequency data list; and
applying a low pass filter operation with a low pass filter onto the multiplied frequency data list to generate a low pass data list, wherein a cutoff frequency of the low pass filter is 1/(2N) times of the sampling frequency of the input data list.
2. The method of claim 1 , wherein a sampling frequency of the N times divide frequency sampling operation is adjustable.
3. The method of claim 1 , wherein a sampling frequency of the N times multiply frequency sampling operation is adjustable.
4. The method of claim 1 , wherein the low pass data list is used to eliminate a far-end echo signal.
5. The method of claim 1 , wherein the method is used in a receiver inside a transceiver.
6. The method of claim 1 , wherein the echo canceller adopts a finite impulse response filter.
7. A method for hardware reduction in a near-end crosstalk canceller, comprising:
applying an N (N is a positive integer) times divide frequency sampling operation onto an input data list of the near-end crosstalk canceller;
applying an N times multiply frequency sampling operation onto an output data list of the near-end crosstalk canceller to generate a multiplied frequency data list; and
applying a low pass filter operation with a low pass filter onto the multiplied frequency data list to generate a low pass data list, wherein a cutoff frequency of the low pass filter is 1/(2N) times of the sampling frequency of the input data list.
8. The method of claim 7 , wherein a sampling frequency of the N times divide frequency sampling operation is adjustable.
9. The method of claim 7 , wherein a sampling frequency of the N times multiply frequency sampling operation is adjustable.
10. The method of claim 7 , wherein the low pass data list is used to eliminate a near-end crosstalk signal.
11. The method of claim 7 , wherein the method is used in a receiver inside a transceiver.
12. The method of claim 7 , wherein the near-end crosstalk canceller adopts a finite impulse response filter.