Patent ID: 8891980

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 matched filter decimator configured to implement an interpolation function that provides decimation on samples taken at substantially two+ε times the symbol rate; 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; and a phase recovery module configured to track and correct phase for the frequency corrected series of data samples.