Patent ID: 8532504

Claim:
An optical coherent receiver comprising: a chromatic dispersion filter that compensates for chromatic dispersion in two polarizations of a received optical signal, the received optical signal comprising a sequence of known data, the sequence of known data beginning, when transmitted, with a pure tone segment comprising substantially a single first frequency; a frequency domain adaptive equalizer that receives output from the chromatic dispersion filter and configured to compensate for impairments in a channel carrying the received optical signal; and, an adaptive equalizer initialization system, coupled to the chromatic dispersion filter and the adaptive equalizer, the initialization system comprising a sequence start detector configured to receive the received optical signal and perform a frequency domain analysis to determine spectral characteristics of the sequence of known data, the spectral characteristics comprising a peak at a second frequency, the peak corresponding to the pure tone segment of the sequence of known data; wherein the initialization system: estimates frequency offset from a difference between the first frequency and the second frequency; estimates chromatic dispersion from the spectral characteristics of the sequence of known data; and loads chromatic dispersion taps into the chromatic dispersion filter based on the estimated frequency offset and estimated chromatic dispersion.