Stable downlink frequency transmission from arbitrary injection point with endless and quick phase error correction.
Stable downlink frequency transmission from arbitrary injection point with endless and quick phase error correction.
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DOI：
10.1364/oe.403849
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发表时间：
2020-10
期刊：
影响因子：
3.8
通讯作者：
Zhongze Jiang;Feifei Yin;Qizhuang Cen;Yitang Dai;Kun Xu
中科院分区：
文献类型：
--
作者：
Zhongze Jiang;Feifei Yin;Qizhuang Cen;Yitang Dai;Kun Xu
提出并论证了一种稳定频率的下行链路传输方案，该方案将频率信号从任意注入点沿着光纤无线电（RoF）环路链路传送回中心站。任意远程点处的频率信号同时在顺时针和逆时针方向上注入RoF环路链路。借助往返辅助频率信号，真实的获得光纤环路引起的相位变化。相位误差可以通过一系列混频（即，上变频和下变频）。在实验中，一个1.21 GHz的频率信号在一个任意的远程点是下行链路传输到中心站在一个45公里的光纤环路链路。结果表明，在0.1 s、1 s和104 s时，重叠Allan偏差（ADEV）分别为1.04×10-12、1.3×10-13和1.1×10-15。相位误差校正完全在中心站进行，从而使远程站点的配置简单而稳健。没有集成有源调节部分，全无源补偿实现了无限的相位误差校正范围，以及对光纤延迟变化的快速响应。
A stable frequency downlink transmission scheme, which delivers the frequency signal back to the central station from an arbitrary injection point along a radio-over-fiber (RoF) loop link, is proposed and demonstrated. The frequency signal at the arbitrary remote point is injected into the RoF loop link in both clockwise and counter-clockwise directions, simultaneously. The phase variation induced by the fiber loop link is obtained in real time with the help of a round-trip assistant frequency signal. The phase error can be exactly cancelled by a series of frequency mixing (i.e., up-conversion and down-conversion) among the signals. In the experiment, a 1.21-GHz frequency signal at an arbitrary remote point is downlink transferred to the central station in a 45-km fiber loop link. The result shows the overlapping Allan deviation (ADEV) of 1.04×10-12 at 0.1 s, 1.3×10-13 at 1 s and 1.1×10-15 at 104 s, respectively. The phase error correction operates entirely at the central station, leaving a simple and robust configuration of the remote site. No active adjusting part is integrated, and the all-passive compensation achieves an endless phase error correction range, as well as quick response to fiber delay changes.