Patent ID: 8693897

Claim:
A digital demodulator device for received optical signals, the digital demodulator comprising: a quadrature error filter module configured to: receive a digitized version of an optical signal; and remove quadrature errors to generate a corrected series of data samples; a frequency offset removal module configured to perform frequency rotation on the corrected series of data samples to generate a frequency corrected series of data samples; a chromatic dispersion compensation module configured to remove, from the frequency corrected series of data samples, chromatic dispersion from horizontal and vertical polarization channels; a polarization mode dispersion (PMD)/polarization dependent loss (PDL) compensation module configured to compensate the frequency corrected series of data samples for interference caused by PMD and PDL; a phase recovery module configured to track and correct phase for the frequency corrected series of data samples; and a symbol timing acquisition and tracking module configured to perform symbol timing acquisition and tracking of the optical signal after the PMD/PDL compensation module compensates for interference caused by PMD and PDL and before carrier phase recovery of the optical signal.