Carrier frequency offset compensation apparatus and associated method

1. A carrier frequency offset compensation method, applied to a communication system, comprising:

mixing, filtering and interpolating an input signal according to a mixing parameter, a first filtering parameter and a first interpolation parameter, respectively, to generate a processed result;

calculating a carrier frequency offset estimation value of the input signal according to the processed result;

adjusting the mixing parameter according to the carrier frequency offset estimation value; and

mixing, filtering and interpolating the input signal according to the adjusted mixing parameter, a second filtering parameter and a second interpolation parameter;

wherein, the first interpolation parameter is associated with a cut-off frequency corresponding to the first filtering parameter.

2. The carrier frequency offset compensation method according to claim 1 , wherein the first filtering parameter differs from the second filtering parameter.

3. The carrier frequency offset compensation method according to claim 2 , wherein a bandwidth corresponding to the first filtering parameter is greater than a bandwidth corresponding to the second filtering parameter.

4. The carrier frequency offset compensation method according to claim 2 , wherein a bandwidth of the second filtering parameter is associated with a symbol rate of the input signal.

5. The carrier frequency offset compensation method according to claim 1 , wherein the second interpolation parameter is associated with a symbol rate of the input signal.

6. The carrier frequency offset compensation method according to claim 1 , wherein the first filtering parameter comprises a signal bandwidth factor and a carrier frequency offset estimation factor.

7. The carrier frequency offset compensation method according to claim 6 , wherein the second filtering parameter does not comprise the carrier frequency offset estimation factor.

8. The carrier frequency offset compensation method according to claim 6 , wherein the first filtering parameter further comprises a roll-off effect estimation factor.

9. A carrier frequency offset compensation method, applied to a communication system, comprising:

mixing, filtering and interpolating an input signal according to a mixing parameter, a first filtering parameter and a first interpolation parameter, respectively, to generate a processed result;

calculating a carrier frequency offset estimation value of the input signal according to the processed result;

adjusting the mixing parameter according to the carrier frequency offset estimation value; and

mixing, filtering and interpolating the input signal according to the adjusted mixing parameter, a second filtering parameter and a second interpolation parameter;

wherein, a bandwidth corresponding to the first filtering parameter is greater than a bandwidth corresponding to the second filtering parameter.

10. A carrier frequency offset compensation apparatus, applied to a communication system, comprising:

a mixer, configured to mix an input signal to generate a frequency shifted signal;

a filter, configured to filter the frequency shifted signal to generate a filtered signal;

an interpolator, configured to interpolate the filtered signal to generate an output signal;

a carrier frequency offset estimator, configured to generate a carrier frequency offset estimation value according to the output signal; and

a controller, when estimating the carrier frequency offset estimation value, configured to control the filter and the interpolator to operate according to a first filtering parameter and a first interpolation parameter, respectively; and, after having estimated the carrier frequency offset estimation value, to adjust a mixing parameter of the mixer according to the carrier frequency offset estimation value, and to control the filter and the interpolator to operate according to a second filtering parameter and a second interpolation parameter, respectively;

wherein, the first interpolation parameter is associated with a cut-off frequency corresponding to the first filtering parameter.

11. The carrier frequency offset compensation apparatus according to claim 10 , wherein the first filtering parameter differs from the second filtering parameter.

12. The carrier frequency offset compensation apparatus according to claim 11 , wherein a bandwidth corresponding to the first filtering parameter is greater than a bandwidth corresponding to the second filtering parameter.

13. The carrier frequency offset compensation apparatus according to claim 11 , wherein a bandwidth of the second filtering parameter is associated with a symbol rate of the input signal.

14. The carrier frequency offset compensation apparatus according to claim 10 , wherein the second interpolation parameter is associated with a symbol rate of the input signal.

15. The carrier frequency offset compensation apparatus according to claim 10 , wherein the first filtering parameter comprises a signal bandwidth factor and a carrier frequency offset estimation factor.

16. The carrier frequency offset compensation apparatus according to claim 15 , wherein the second filtering parameter does not comprise the carrier frequency offset estimation factor.

17. The carrier frequency offset compensation apparatus according to claim 15 , wherein the first filtering parameter further comprises a roll-off effect estimation factor.