Unmanned aerial vehicles (UAVs) are attracting increasing attention for applications such as video streaming, surveillance, and delivery using reliable line-of-sight (LOS) links. Nevertheless, due to the large radio-frequency (RF) transmission footprint from a UAV transmitted to ground nodes, UAV communications may significantly deteriorate the performance of cochannel ground communication links. With the lack of a dedicated spectrum, researchers need to design efficient spectrum-sharing policies for UAV communications to enhance spectral efficiency (SE) and control interference-to-ground communications. One technique for spectrum sharing is spatial spectrum sensing (SSS), which enables devices to sense spatial spectrum opportunities and reuse them aggressively and efficiently by controlling the SSS radius. The goal of this article is to introduce the fundamentals, challenges, and applications of SSS for UAV spectrum access and discuss open research problems for realizing UAV spectrum sharing, including dynamic spectrum access for swarm UAV networks, artificial intelligence (AI)-enabled UAV spectrum access, blockchain-based UAV spectrum access, multichannel access for UAVs, and the integration of UAVs into cellular networks.

中文翻译：

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无人机通信频谱共享：空间频谱感知和开放问题

无人机 (UAV) 在视频流、监视和使用可靠视距 (LOS) 链路的交付等应用中越来越受到关注。然而，由于从无人机传输到地面节点的射频 (RF) 传输足迹较大，无人机通信可能会显着降低同信道地面通信链路的性能。由于缺乏专用频谱，研究人员需要为无人机通信设计有效的频谱共享策略，以提高频谱效率 (SE) 并控制对地通信的干扰。一种频谱共享技术是空间频谱感知 (SSS)，它使设备能够感知空间频谱机会并通过控制 SSS 半径积极有效地重用它们。