In this letter, we introduce accurate approximation expressions for composite fading channel model and outage probability of multiple-input multiple-output (MIMO) free space optical (FSO) link between two unmanned aerial vehicles (UAVs) in hovering state. In our derivations, we consider the effects of weather attenuation, random fluctuations in UAVs’ positions and orientations, and atmospheric turbulence. Our proposed model is unified with respect to turbulence effect, which means it is valid for different atmospheric turbulence models. We show the accuracy of the proposed model through comparisons with Monte Carlo simulations under different channel conditions.

中文翻译：

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存在大气湍流和指向误差的空中 MIMO FSO 链路的复合衰落模型

在这封信中，我们介绍了两架无人机 (UAV) 悬停状态下多输入多输出 (MIMO) 自由空间光学 (FSO) 链路的复合衰落信道模型和中断概率的精确近似表达式。在我们的推导中，我们考虑了天气衰减、无人机位置和方向的随机波动以及大气湍流的影响。我们提出的模型在湍流效应方面是统一的，这意味着它适用于不同的大气湍流模型。我们通过与不同信道条件下的蒙特卡罗模拟进行比较，展示了所提出模型的准确性。