中文摘要：

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。

英文摘要：

In coherent optical orthogonal frequency division multiplexing（CO-OFDM）system,the variance of the phase noise becomes larger when line-width of the laser increases,which can introduce more inter-carrier interference（ICI）in frequency domain and severely degrade the performance of the system.In addition,CO-OFDM system becomes more sensitive to phase noise when the modulation format order is increased.In order to decrease the influence of the phase noise in systems which employs the larger line-width laser and the higher order modulation,a novel three-stage phase noise compensation algorithm based on Kalman filtering is proposed.The novel algorithm is divided into three stages：coarse phase noise compensation in time domain,residuary common phase error（CPE）suppression in frequency domain and fine phase noise compensation in time domain.The mathematical model of the algorithm is given out.Mentor-Carol simulations are researched on the models.The simulation analysis shows that the proposed algorithm,compared with several phase noise suppression algorithms,has the lower bit error rate（BER）at a large laser line-width and can improve the system′s tolerance of the laser line-width.