This article studies the air-to-ground ultra-wideband channel through propagation measurements between 3.1 to 4.8 GHz using unmanned-aerial-vehicles (UAVs). Different line-of-sight (LOS) and obstructed-LOS scenarios and two antenna orientations were used in the experiments. Multipath channel statistics for different propagation scenarios were obtained, and the Saleh–Valenzuela model was found to provide a good fit for the statistical channel model. An analytical path loss model based on antenna gains in the elevation plane is provided for unobstructed UAV hovering and moving (in a circular path) propagation scenarios.

中文翻译：

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开放区域中的超宽带空对地传播信道特性

本文使用无人机 (UAV) 通过 3.1 至 4.8 GHz 之间的传播测量来研究空对地超宽带信道。实验中使用了不同的视线 (LOS) 和障碍物 LOS 场景以及两种天线方向。获得了不同传播场景的多径信道统计数据，发现 Saleh-Valenzuela 模型可以很好地拟合统计信道模型。为无障碍无人机悬停和移动（在圆形路径中）传播场景提供了基于仰角平面天线增益的分析路径损耗模型。