Patent ID: 7457347

Claim:
A receiver comprising: an equalizer configured to perform equalization on a sample data stream and generate filter tap values based on the equalization; a frequency error estimator coupled to the equalizer, the frequency error estimator configured to generate an estimated frequency error signal based on at least one of the filter tap values; a controller coupled to the frequency error estimator, the controller configured to adjust the gain of the estimated frequency error signal; an oscillator coupled to the controller, the oscillator configured to generate a rotating phasor signal based on the estimated frequency error signal; and a first multiplier coupled to the oscillator and the equalizer, the first multiplier configured to multiply the rotating phasor signal with the sample data stream to correct the frequency of the sample data stream, wherein the frequency error estimator comprises: a tap extraction unit for extracting an appropriate tap value from the filter tap values generated by the equalizer and outputting the extracted tap value; a delay unit coupled to the tap extraction unit for delaying the extracted tap value; a conjugate generator coupled to the tap extraction unit and the delay unit for generating a conjugate of the extracted tap value; a second multiplier coupled to the delay unit and the conjugate generator for multiplying 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 second multiplier for measuring the phase difference between the conjugate extracted tap value and the delayed extracted tap value; a first filter for averaging the measured phase difference, whereby the averaged phase difference is output from the frequency error estimator as the estimated frequency error signal; and a comparator circuit coupled to the second multiplier and the first filter for selectively sending a hold signal to the first filter based on a value of a threshold signal, wherein the hold signal causes the first filter to pause.