文章对两种双频率波段的光纤无线通信(Radio-Over-Fiber，ROF)系统模型进行了仿真分析。首先基于文献实验，实现了使用一个马赫-曾德调制器直接调制双频率波段的ROF系统模型，然后改为使用两个马赫-曾德调制器分别调制两个波段的系统模型。结果表明，在误码率BER=10-9，光纤长度为55 km的情况下，对于40 GHz频段，改进后的系统比改进前的系统性能提高5 dBm；从敏感度曲线上也可以看出，改进后的系统性能更稳定。

In this paper, two kinds of double-frequency Radio over Fiber (RoF) system models are simulated. On the basis of experiments, a RoF system model, whose double-frequency waveband is directly modulated by a Mach-Zehnder modulator, is realized. Then, it is improved into a system model, whose two wavebands are modulated with two Mach-Zehnder modulators respectively. The results show that when BER=10-9 and the fiber length is 55 km, the improved system is 5 dBm better at the 40 GHz frequency band and more stable in terms of sensitivity than the former.