Patent ID: 8111788

Claim:
A baseband frequency correction (BFC) apparatus comprising: an equalizer configured to perform equalization on a sample data stream and to generate filter tap values based on the equalization; and a frequency error estimator configured to generate an estimated frequency error signal based on at least one of the filter tap values, the frequency error estimator comprising: a tap extraction unit configured to extract an appropriate tap value from the filter tap values generated by the equalizer and to output the extracted tap value; a delay unit coupled to the tap extraction unit configured to delay the extracted tap value; a conjugate generator coupled to the tap extraction unit and the delay unit configured to generate a conjugate of the extracted tap value; a first multiplier coupled to the delay unit and the conjugate generator configured to multiply the conjugate of the extracted tap value with the delayed extracted tap value to generate a phase difference signal which represents the phase difference between the conjugate extracted tap value and the delayed extracted tap value; an arctangent unit coupled to the output of the first multiplier configured to measure the phase difference between the conjugate extracted tap value and the delayed extracted tap value; and a first filter configured to average the measured phase difference, whereby the averaged phase difference is output from the frequency error estimator as the estimated frequency error signal.