DGD Tolerant Fast RSOP Tracking Scheme based on Multi-symbol Extended Kalman Filter in 16QAM Coherent Optical systems

This paper proposes a scheme of tracking fast rotation of the state of polarization (RSOP), which uses multi symbols to update the parameters of extended Kalman filter (EKF) and thus significantly improves differential group delay (DGD) tolerance. Simulation results of polarization division multiplexing 16-ary quadrature amplitude modulation (PDM16QAM) systems indicate that the proposed scheme has better DGD tolerance capability than the symbol-by-symbol traditional EKF algorithm, and it increases the maximum tolerance of DGD from 6ps to 14ps with the 9Mrad/s RSOP.