为了满足小卫星平台中尺寸、质量、功耗等约束并探索中短距离星间链路下射频(RF)通信和激光通信的替代解决方案,研究了多卫星网络中采用可见光通信(VLC)的中短距离星间通信的可行性。利用卫星工具软件(STK)构建了双星伴飞构型,定量分析了太阳及恒星引入的背景光噪声,从而构建了中短距离星间VLC链路模型。为了提高链路容量和可靠性,进一步构建了基于星间链路的单输入多输出VLC(SIMO-VLC)系统,通过数值仿真评估了不同分集合并算法对于链路性能的影响。仿真结果表明:大部分时段中太阳辐射引入的杂散光功率在10 μW以下,相比于地面场景引入的背景光功率降低了75%。当在20 km内实现传输速率为112.5 Mbit/s、误码率为1×10 -6的数据传输,系统所需的发射光功率至少为4.55 W。相比单输入单输出(SISO)系统,采用基于单输入多输出(SIMO)的分集检测方案可以获得更好的性能,且所需发射功率和通信距离能够随着接收支路的增加得以有效改善,可为基于VLC的星间链路设计及扩展室外应用场景提供参考。

To meet constraints on size, weight, and power consumption in small satellite platforms and explore alternative solutions for radio frequency and laser-based communication in medium- and short-distance inter-satellite links, this study explores the feasibility of visible-light communication (VLC) based medium- and short-distance inter-satellite communication in multi-satellite networks. Using the satellite tool kit (STK), the binary star formation flying configuration is constructed, background-light noise introduced by the sun and stars is quantitatively analyzed, and a medium- and short-range inter-satellite VLC link model is constructed. Then, to improve the link capacity and reliability, the VLC link is further developed into a single-input multi-output VLC (SIMO-VLC) system. The influences of different diversity merging algorithms on the link’s performance are evaluated by numerical simulation. Simulation results show that the stray light power introduced by solar radiation is below 10 μW throughout most of the time period, and the background light power introduced from the ground is reduced by 75%. In order to achieve a data transmission rate of 112.5 Mbit/s and a bit error rate of 1×10 ^-6 within 20 km, the light power required by the system is at least 4.55 W. Compared with the single-input single-output system, the SIMO-based diversity detection scheme can achieve better performance, and the required transmission power and communication distance are effectively improved with the increase of the receiving branch, which can provide a reference for the design of VLC-based inter-satellite links and extending their outdoor application scenarios.