针对偏振复用相干光通信系统链路中存在的高速偏振态旋转造成的信道损伤、相干接收机的动态均衡算法模块在实际系统中存在的反馈延迟导致的偏振态追踪性能不足的问题,提出一种基于互补斯托克斯向量的偏振态旋转的追踪和预测算法。所提算法将测得的琼斯空间中的偏振旋转矩阵和其逆矩阵变换到斯托克斯空间,并计算得到一对互补向量,并对斯托克斯空间中的互补向量的运动轨迹进行追踪和预测,以实现链路偏振态旋转的补偿。仿真结果表明,在均衡反馈延迟为5帧时,通过对互补向量进行循迹,预测的琼斯矩阵的平方误差可比原始方案降低10%。通过采用所提算法,系统的偏振旋转速度容限从1.3 MHz提升至1.5 MHz。

The high-speed polarization state rotation associated with the polarization multiplexing coherent optical communication system link causes channel damage. Further, the feedback delay associated with the dynamic equalization algorithm module of the coherent receiver in the actual system results in insufficient polarization state tracking performance. In this study, a tracking and prediction algorithm for polarization state rotation is proposed based on complementary Stokes vectors to resolve the aforementioned problems. The proposed algorithm initially transforms the measured polarization rotation matrix of the Jones space and its inverse matrix into the Stokes space, obtains a pair of complementary vectors, and tracks and predicts the motion trajectories of the complementary vectors in Stokes space. Finally, the compensation of the polarization state rotation of the link is realized. The simulation results show that the squared error of the predicted Jones matrix can be reduced by 10% compared with that in the original scheme by tracking the complementary vector when the equalization feedback delay is 5 frames. Furthermore, the polarization rotation speed tolerance of the system increases from 1.3 MHz to 1.5 MHz when using the proposed algorithm.