Patent ID: 7747169

Claim:
An apparatus, comprising: an optical receiver configured to recover data from a PSK modulated optical carrier, the optical receiver comprising: an optical detector configured to produce a sequence of vectors having first and second digital components, each first component being indicative of a complex value of a first polarization component of the modulated optical carrier at a corresponding sampling time, and each second component being indicative of a complex value of a different second polarization component of the modulated optical carrier at the sampling time; and a digital processor connected to receive the vectors and being configured to perform a rotation on each received vector individually in a manner that compensates for polarization rotations produced by transmitting the modulated optical carrier from an optical transmitter thereof to the optical receiver; and wherein the digital processor is configured to iteratively update each angle of the rotation by an amount proportional to a difference between magnitudes of the components of a vector produced by an earlier one of the rotations.