对于偏分复用相干光正交频分复用(PDM-CO-OFDM)通信系统,提出了两种盲相位估计算法,一种基于判决引导(DD)的方案,另一种基于判决引导和判决反馈相结合(DD+DF)的方案。随后在112Gb/s的PDM-COOFDM系统中对算法进行了仿真验证,并与传统的导频辅助(PA)算法进行比较,结果表明DD算法在无需导频开销的情况下,可实现良好的相位估计性能,但对激光器线宽的容忍度较差,DD+DF算法对DD算法的相位估计性能及激光器线宽容忍度都有较高的提升,且其相位恢复结果明显优于采用五路导频的PA算法。 For PDM-CO-OFDM communication systems, two blind phase estimation algorithms are proposed, one based on decision-directed (DD) scheme and the other based on decision-directed Decision feedback combined with (DD + DF) scheme. Then, the algorithm is validated in a 112Gb / s PDM-COOFDM system and compared with the traditional pilot-assisted (PA) algorithm. The results show that the DD algorithm can achieve good phase without pilot overhead However, the tolerance to laser linewidth is poor. The DD + DF algorithm has higher performance on phase estimation and laser linewidth tolerance of DD algorithm, and its phase recovery result is obviously better than that of the five-lead Frequency of the PA algorithm.