提出了一种基于偏振分集的相干光正交频分复用(OFDM)链路。然而相干检测对相位噪声比较敏感，偏振分集接收过程又会产生额外的乘性相位噪声，因此基于偏振分集相干光OFDM系统，提出了基于数字信号处理的相位噪声消除方案。在100 km单模光纤中，以8 Gbit/s的传输速率零误码传输16进制正交振幅调制OFDM信号，经相干检测之后，基于数字信号处理，对相干光OFDM信号完成了相位噪声消除，并对相位噪声消除后的信号星座图进行了实验结果分析。另外，还将经过相位噪声消除后的偏振分集相干光OFDM链路与其他相干光OFDM链路方案进行了性能对比，从而验证了此方案的优越性。

The coherent optical orthogonal frequency division multiplexing (OFDM) system based on polarization diversity is proposed. However, the coherent detection is very sensitive to phase noise and the polarization diversity reception can produce additional multiplicative phase noise. Therefore, a phase noise cancellation scheme based on digital signal processor with coherent optical OFDM system is proposed. Error-free transmission of an 8 Gbit/s 16 quadrature amplitude modulation OFDM signal over a 100 km single mode fiber is experimentally demonstrated. After the coherent detection, the phase noise through digital signal processing is cancelled, and the experimental constellation diagrams of the signals after phase noise cancellation is analyzed. In addition, the coherent optical OFDM link based on polarization diversity after phase noise cancelling is compared with other coherent optical OFDM link as the advantage of this scheme is verified.