在偏振复用(PDM)高速光通信系统的相干检测中，需要实现信号偏振态和载波相位的快速跟踪。将扩展卡尔曼滤波器用在偏振复用16进制正交振幅调制(PDM-16QAM)光调制信号相干接收机中，成功实现了偏振态和载波相位的快速精确跟踪。在单信道112 Gb/s PDM-16QAM传输系统中，数值仿真发现，扩展卡尔曼滤波器所能跟踪的最大偏振态旋转速率可达级联多模算法的100倍，而且具有很好的收敛精度，其收敛速度和精度可以通过调优参量控制。使用扩展卡尔曼滤波器跟踪100 kHz线宽18 Mrad/s偏振态旋转信号时，10-3误码率(BER)对应的接收机灵敏度代价仅为0.2 dB。研究了应用于长距离传输光通信系统的扩展卡尔曼相干接收的性能。

In the coherent receiver of polarization division multiplexing (PDM) optical communication system, the modules of polarization demultiplexing and carrier phase recovery are required. Extended Kalman filter is used into polarization division multiplexing-16 quadrature amplitude modulation (PDM-16QAM) coherent receiver to achieve polarization and phase tracking quickly and accurately. In the single channel 112 Gb/s PDM-16QAM optical communication system, the simulation results show that the maximum polarization rotation rate of extended Kalman filter tracking is nearly 100 times faster than that of Cascade multimode algorithm. Meanwhile, Kalman filter also has a high accuracy, and the convergence speed and accuracy can be controlled by adjusting the tuning parameters.Specifically, only 0.2 dB sensitivity penalty at the bit error rate (BER) limit of 10-3 is induced when extended Kalman filter is applied on the signal with 100 kHz line width and 18 Mrad/s polarization rotation. A long-haul transmission simulation is raised to test the performance of extended Kalman filter.