在相干光正交频分复用系统(CO-OFDM)中,相位噪声的方差随着激光器线宽的增加而增加,从而在频域引入更大载波间干扰,对系统的性能造成极大的影响,同时调制方案阶数的增加会使系统对相位噪声更加敏感。针对激光器线宽较大和采用高阶调制的系统,提出了一种基于卡尔曼滤波的三阶相位噪声补偿算法。算法的3个阶段为时域相位噪声粗补偿、频域残余CPE消除和时域相位噪声精补偿,并给出了算法3个阶段的数学模型。所提出算法与现有的其它几种算法进行了仿真对比分析表明,在激光器线宽较大时,所提出算法具有更低的误码率(BER),能较大幅度的提高CO-OFDM系统对激光器线宽的容忍度。 In Coherent Optical Orthogonal Frequency Division Multiplexing (CO-OFDM) systems, the variance of phase noise increases as the laser linewidth increases, leading to greater intercarrier interference in the frequency domain, which can significantly increase the performance of the system Influence, at the same time the increase of the modulation scheme order makes the system more sensitive to the phase noise. Aiming at the system with high laser linewidth and high order modulation, a third-order phase noise compensation algorithm based on Kalman filter is proposed. The three phases of the algorithm are the coarse phase noise compensation, the residual CPE elimination in the frequency domain and the phase noise compensation in the time domain. The mathematical model of the algorithm is given in three stages. The simulation results show that the proposed algorithm has a lower bit error rate (BER) when the laser linewidth is larger, and can greatly improve the CO-OFDM system Tolerance of laser line width.