Method and apparatus for blind time skew compensation for coherent optical receivers

摘要

In some embodiments, an apparatus includes a coherent optical receiver that can receive during a first time period a set of in-phase signals and a set of quadrature signals having a skew from the set of in-phase signals. The coherent receiver can blindly determine a delay between the set of in-phase signals and the set of quadrature signals based on the set of in-phase signals and the set of quadrature signals. The delay includes an intersymbol portion and an intrasymbol portion. The coherent optical receiver can apply the delay at a second time after the first time period such that a skew after the second time is less than the skew at the first time period.

主权项

1. An apparatus, comprising:
a coherent optical receiver configured to receive during a first time period a plurality of in-phase signals and a plurality of quadrature signals having a skew from the plurality of in-phase signals, the plurality of the in-phase signals and the plurality of quadrature signals being associated with a local oscillator signal having a wavelength different from a wavelength of an optical carrier signal associated with a transmitter, the coherent optical receiver configured to sweep a plurality of index delays associated with at least one of the plurality of in-phase signals or the plurality of quadrature signals to calculate a plurality of error signals associated with a difference between the wavelength of the local oscillator signal associated with the coherent optical receiver and the wavelength of the optical carrier signal associated with the transmitter such that a delay between the plurality of in-phase signals and the plurality of quadrature signals is blindly determined, the delay having an intersymbol portion and an intrasymbol portion, the coherent optical receiver configured to apply the delay at a second time after the first time period such that a skew after the second time is less than the skew at the first time period.