Patent ID: 8774644

Claim:
A method comprising the steps of: receiving an optical signal; generating, from a plurality of outputs of a Fourier transform circuit, frequency domain data in response to time domain data associated with the optical signal; determining a first parameter based on components of the frequency domain data supplied from selected ones of the plurality of outputs of the Fourier transform circuit, said first parameter being indicative of a phase difference between selected ones of the plurality of components; filtering the first parameter to compensate for an estimated value of chromatic dispersion; determining a second parameter indicative of a clock phase of the optical signal based on said first parameter; using the second parameter to synchronize a receiver clock with the clock phase of the optical signal; and calculating an average value of the first parameter over a predetermined time period, wherein the time domain data has an associated baud frequency, and selected ones of the plurality of outputs of the Fourier transform circuit are associated with components of the frequency domain data that are spectrally spaced from one another by the baud frequency.