Unmanned aerial vehicles (UAVs) and Terahertz (THz) technology are envisioned to play paramount roles in next-generation wireless communications. In this paper, we present a novel secure UAV-assisted mobile relaying system operating at THz bands for data acquisition from multiple ground user equipments (UEs) towards a destination. We assume that the UAV-mounted relay may act, besides providing relaying services, as a potential eavesdropper called the untrusted UAV-relay (UUR). To safeguard end-to-end communications, we present a secure two-phase transmission strategy with cooperative jamming. Then, we devise an optimization framework in terms of a new measure $-$ secrecy energy efficiency (SEE), defined as the ratio of achievable average secrecy rate to average system power consumption, which enables us to obtain the best possible security level while taking UUR's inherent flight power limitation into account. For the sake of quality of service fairness amongst all the UEs, we aim to maximize the minimum SEE (MSEE) performance via the joint design of key system parameters, including UUR's trajectory and velocity, communication scheduling, and network power allocation. Since the formulated problem is a mixed-integer nonconvex optimization and computationally intractable, we decouple it into four subproblems and propose alternative algorithms to solve it efficiently via greedy/sequential block successive convex approximation and non-linear fractional programming techniques. Numerical results demonstrate significant MSEE performance improvement of our designs compared to other known benchmarks.
翻译:无人驾驶航空飞行器(UAVs)和Terahertz(THz)技术预计将在下一代无线通信中发挥最重要的作用。 在本文中,我们提出了一个在Thz波段运行的新型安全的UAV辅助移动中继系统,用于从多个地面用户设备(UES)获取数据,从多个地面用户设备(UES)到目的地。我们假设,UAV挂载的中继器除了提供中继服务之外,还可以作为潜在的窃听器发挥作用,称为无人信任的UAV-Relay(UUR)。为了保障终端到终端通信的公平性能。我们的目标是通过联合设计关键系统参数(包括UPRO-NUEE)的两阶段安全传输战略,通过合作干扰,我们设计了一个以美元为单位的保密节能能效的新措施(SEEE),其定义为可实现的平均保密率率相对于平均系统电耗能消耗量的比例,这使我们能够在考虑UUR固有的飞行能力限制的情况下获得最佳的安保水平。为了服务质量,我们的目标是通过所有UEUEV-S-SUEE(MSE)最低性改进基准,通过联合配置解决方案的解决方案的解决方案参数,包括UPROl-rleval rol lial lial lial oral comal oral oral commal commal commal commal lectional lectional ladingal ladingal ladingal ladingal ladings) ladings)。