The integration of unmanned aerial vehicle (UAV) networks and device-to-device (D2D) communications is expected to provide ubiquitous connectivity and high-speed rates for sensitive information transmission in future wireless networks. However, the traditional cryptography and physical layer security techniques still cannot prevent adversaries from knowing the existence of information transmission such that they further launch attacks on transmitters and receivers. Covert communication can offer an even stronger level of security via hiding the information transmission process of wireless networks. In this article, we first integrate D2D communications into UAV networks, and then investigate the fundamental issues of mode selection and cooperative jamming for covert communication in such networks, aiming to provide a powerful security solution to support widespread securi-ty-sensitive applications of such networks. To this end, we propose two promising D2D underlaid UAV network architectures, whereby each UAV acts as either a flying BS or an aerial UE. Then, we propose a covert communication strategy by combining mode selection and cooperative jamming, where mode selection allows each user equipment to adaptively switch between half-du-plex and full-duplex communication modes, and cooperative jamming means that idle D2D pairs inject interference to confuse adversaries. The goal of the proposed strategy is to enhance covert capacity performance (i.e., the maximum channel rate) while maintaining a high detection error probability at adversaries in the promising network architectures. Numerical results are presented to evaluate our strategy of mode selection and cooperative jamming, and to illustrate performance gains in terms of covert capacity and detection error probability in these two network architectures. Finally, a vision is discussed for our future research in D2D underlaid UAV networks.

中文翻译：

---

D2D 底层无人机网络中隐蔽通信的模式选择和协作干扰


无人机（UAV）网络和设备到设备（D2D）通信的集成预计将为未来无线网络中的敏感信息传输提供无处不在的连接和高速速率。然而，传统的密码学和物理层安全技术仍然无法阻止对手获知信息传输的存在，从而进一步对发射器和接收器发起攻击。隐蔽通信可以通过隐藏无线网络的信息传输过程来提供更强的安全级别。在本文中，我们首先将D2D通信集成到无人机网络中，然后研究此类网络中隐蔽通信的模式选择和协作干扰的基本问题，旨在提供强大的安全解决方案来支持此类网络的广泛安全敏感应用。网络。为此，我们提出了两种有前途的 D2D 底层无人机网络架构，其中每个无人机既可以充当飞行 BS，也可以充当空中 UE。然后，我们提出了一种结合模式选择和协作干扰的隐蔽通信策略，其中模式选择允许每个用户设备自适应地在半双工和全双工通信模式之间切换，而协作干扰意味着空闲的D2D对向系统注入干扰。迷惑对手。所提出策略的目标是增强隐蔽容量性能（即最大信道速率），同时在有前途的网络架构中保持对手的高检测错误概率。 给出的数值结果是为了评估我们的模式选择和协作干扰策略，并说明这两种网络架构中隐蔽容量和检测错误概率方面的性能增益。最后，讨论了我们未来 D2D 底层无人机网络研究的愿景。