Clock Recovery and Rx/Tx IQ skew Compensation Based on Polarization Transforming and Interpolation for Long-haul Coherent Receivers

For Nyquist coherent optical transmission systems with high symbol rate and high order modulation format, clock error and Rx/Tx IQ skew can seriously degrade system performance. In this paper, a clock recovery and Rx/Tx IQ skew compensation scheme based on polarization transforming and interpolation is proposed, which can eliminate the impact of singularity. Besides, the scheme has lower complexity compared with TD 4×2 MIMO equalizer scheme.