基于FBOC调制的高精度光纤双向时频比对方法

High precision fiber bidirectional time-frequency comparison method based on FBOC modulation

为了提高光纤双向时频传递系统的传递精度,解决系统码相位测量不确定度过大的问题,提出了一种基于灵活二进制偏移载波(FBOC)调制方式的光纤双向时频比对方法,利用FBOC调制信号的良好自相关特性,降低码相位测量不确定度,在100km室内光纤中完成了实验验证,时间传递稳定度达到3.37ps/s,频率传递稳定度达到4.74×10^(-16)/40000s;仿真了FBOC调制信号的码相位测量不确定度,其值约为3.5ps,远小于传统二进制相移键控调制信号的码相位测量不确定度。

In order to improve the precision of two-way time and frequency transfer system via optical fiber, to solve the problem that system code phase measurement uncertainty is too large, in this paper, the two-way time and frequency comparison method via optical fiber based on flexible binary offset carrier(FBOC) modulation is developed. By taking the advantage of the good self-correlation features of FBOC modulation signal, the code phase measurement uncertainty is reduced. The experiment in 100km spooled optical fiber is completed. Time transfer stability is 3.37ps/s and frequency transfer stability is 4.74×10-16/40000s. The code phase measurement uncertainty of FBOC modulated signal is simulated, and the value is 3.5ps, which is much smaller than that of traditional binary phase shift keying modulated signal.