发表机构
LiFi Research and Development Centre, Department of Engineering, Cambridge University; European Space Agency（剑桥大学工程与LiFi研发中心; 欧洲空间局）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文针对光学星间链路提出解析信道模型，揭示中断概率由较弱终端主导而遍历容量取决于双端综合稳定性，为波束参数设计提供指南。
AI 中文摘要
光学星间链路（OISL）是大容量空间网络和下一代卫星星座的关键使能技术。然而，其极强的方向性使得链路可靠性对平台引起的指向抖动高度敏感，抖动会导致发射和接收波束之间的随机失准。本文针对两端存在独立指向误差的点对点OISL，开发了一个易处理的闭式统计信道模型。对发射远场方向图和接收耦合效率采用了精确的高斯主瓣近似。这将基于衍射的信道响应转化为信道增益分布、中断概率和遍历容量的闭式表达式。解析结果通过蒙特卡洛模拟验证，并用于研究终端稳定性、波束发散角和链路余量对OISL性能的影响。结果表明，中断概率由指向稳定性较弱的终端主导，而仅改善较强终端带来的额外收益极小。相反，遍历容量损失取决于两个终端的综合稳定性，揭示了可靠性与吞吐量指标之间的根本区别。所提出的框架为在不同平台不稳定性水平下选择波束参数以及指定指向和跟踪要求提供了实用的设计指南。
英文摘要
Optical inter-satellite links (OISLs) are key enablers for high-capacity space networks and next-generation satellite constellations. However, their extreme directionality makes link reliability highly sensitive to platform-induced pointing jitter, which causes random misalignment between the transmitter and receiver beams. In this paper, we develop a tractable closed-form statistical channel model for point-to-point OISLs subject to independent pointing errors at both terminals. Accurate Gaussian main-lobe approximations are applied to the transmitter far-field pattern and receiver coupling efficiency. This transforms the diffraction-based channel response into closed-form expressions for the channel-gain distribution, outage probability, and ergodic capacity. The analytical results are validated through Monte Carlo simulations and used to study the impact of terminal stability, beam divergence, and link margin on OISL performance. The results show that outage probability is governed by the weaker terminal in terms of pointing stability, while improving only the stronger terminal provides minimal additional benefit. In contrast, the ergodic-capacity penalty depends on the combined stability of both terminals, revealing a fundamental distinction between reliability and throughput metrics. The proposed framework provides practical design guidelines for selecting beam parameters and specifying pointing and tracking requirements under varying levels of platform instability.
