对于偏分复用的正交相移键控(PM-QPSK)相干接收系统,提出了一种修正的基于高阶统计矩的光信噪比(OSNR)监测方案,讨论了不同占空比调制格式的修正结果以及该修正结果对剩余色散(CD)和偏振模色散(PMD)的容忍度。搭建了112Gb/s PM-QPSK系统仿真平台,对8dB~26dB范围内的光信噪比进行了测量,结果表明提出的修正方案对不同码型的监测误差均小于0.5dB。并且当OSNR为14dB时,在0.5dB的监测误差范围内,对CD的容忍度约为2800ps/nm,对一阶PMD的容忍度约为65ps。因此,这种修正方案可用于PM-QPSK相干接收系统中带内实时OSNR监测,且计算复杂度小、不需要额外的监测设备。 For PM-QPSK coherent receiving system, a modified OSNR monitoring scheme based on high-order statistical moments is proposed. Different duty cycle modulation The results of the correction of the format, and the tolerance of the results of the correction for residual dispersion (CD) and polarization mode dispersion (PMD). The 112Gb / s PM-QPSK system simulation platform is built and the optical signal-to-noise ratio in the range of 8dB ~ 26dB is measured. The results show that the proposed correction scheme has less than 0.5dB error for different patterns. And when the OSNR is 14dB, the tolerance to CD is about 2800ps / nm and the tolerance to first-order PMD is about 65ps within the monitoring error of 0.5dB. Therefore, this correction scheme can be used for in-band real-time OSNR in-band monitoring in PM-QPSK coherent receiving systems with low computational complexity and no additional monitoring equipment.