Phase skew compensation at a coherent optical receiver

摘要

It is disclosed a coherent optical receiver configured to receive a modulated optical signal and to generate an in-phase component and a quadrature component. The optical coherent receiver comprises a phase skew compensator in turn comprising a first digital circuit and a second digital circuit retroactively connected between an output and a control input of the first digital circuit. The first digital circuit provides a compensated in-phase component as a sum of the in-phase component multiplied by a first gain and the quadrature component multiplied by a second gain, and a compensated quadrature component as a sum of the in-phase component multiplied by a third gain and the quadrature component multiplied by a fourth gain. The second digital circuit computes the first, second, third and fourth gain as functions of an estimated cross-correlation between the compensated in-phase component and the compensated quadrature component.