在相干光纤通信系统中, 恒模算法(CMA)是一种最为常见的抑制偏振模色散(PMD)的算法。为了进一步降低接收机数字信号处理(DSP)后的误比特率(BER), 提出了一种基于提升光纤通信系统传输速率的CMA改进措施。采用将靠近星座图坐标轴的若干个散点推向邻近区间的方法进行优化, 计算并比较了传统CMA和改进CMA的BER, 设计了相关仿真实验。仿真分析结果表明: 改进CMA使补偿的传输速率提升3.46%(BER=0)；若对BER的要求为2×10-4, 则传输速率还可再提升1.33%。

In coherent optical fiber communication system, constant modulus algorithm(CMA) is one of the most common algorithm to suppress polarization mode dispersion(PMD). In order to further reduce the bit error rate(BER) after digital signal processing(DSP) of the receiver, a CMA improvement measure based on improving the transmission rate of optical fiber communication system is proposed. The BER of the traditional CMA and the improved CMA are calculated and compared, and the relevant simulation experiments are designed. The simulation results show that the improved CMA improve the compensated transmission rateby 3.46%(BER=0). If the BER requirement is 2×10-4, the transmission ratecan be further improve by 1.33%.