Method and system for improved tolerance to linear and nonlinear impairments

A method, comprising:

• generating, by a processing system including a processor, an error estimate based on information from a carrier phase recovery system that digitally recovers a carrier phase associated with a signal of a first polarization;
• deriving, by the processing system, a first filter coefficient based on the error estimate and estimated symbols of the signal, wherein the first filter coefficient is a complex value;
• deriving, by the processing system, a second filter coefficient based on the error estimate and estimated symbols of another signal of a second polarization orthogonal to the first polarization, wherein the second filter coefficient is a complex value;
• and
• using, by the processing system, the first filter coefficient and the second filter coefficient to at least partially compensate for impairments relating to the signal.

A circuit configured to:

• generate a first error estimate based on first information from a carrier phase recovery system relating to a first signal of a first polarization, and a second error estimate based on second information from the carrier phase recovery system relating to a second signal of a second polarization orthogonal to the first polarization;
• derive a first filter coefficient based on the first error estimate, estimated symbols of the first signal, the second error estimate, and estimated symbols of the second signal, wherein the first filter coefficient is a complex value;
• derive a second filter coefficient based on the first error estimate, the estimated symbols of the first signal, the second error estimate, and the estimated symbols of the second signal, wherein the second filter coefficient is a complex value;
• and
• use the first filter coefficient and the second filter coefficient to at least partially compensate for impairments relating to the first signal and the second signal.