Carrier frequency offset compensation apparatus and associated method

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.

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.