Unmanned aerial vehicles (UAVs) have steadily gained attention to overcome the harsh propagation loss and blockage issue of millimeter-wave communication. However, UAV communication systems suffer from energy consumption, which limits the flying time of UAVs. In this paper, we propose several UAV energy consumption minimization techniques through the aid of multiple intelligent reflecting surfaces (IRSs). In specific, we introduce a tractable model to effectively capture the characteristics of multiple IRSs and multiple user equipments (UEs). Then, we derive a closed form expression for the UE achievable rate, resulting in tractable optimization problems. Accordingly, we effectively solve the optimization problems by adopting the successive convex approximation technique. To compensate for the high complexity of the optimization problems, we propose a low complexity algorithm that has marginal performance loss. In the numerical results, we show that the proposed algorithms can save UAV energy consumption significantly compared to the benchmark with no IRSs, justifying that exploiting the IRSs is indeed favorable to UAV energy consumption minimization.
翻译:无人驾驶航空飞行器(UAVs)稳步获得关注,以克服严重传播损失和隔热的毫米波通信问题。然而,无人驾驶航空飞行器通信系统受到能源消耗的影响,这限制了UAV的飞行时间。在本文中,我们提出若干无人驾驶航空飞行器的能源消耗最小化技术,借助多个智能反射表面(IRS),具体地说,我们引入了一种可移植模型,以有效捕捉多种IRS和多用户设备(UES)的特性。然后,我们为UE可实现的速率找到一种封闭式表达方式,从而导致可移植的优化问题。因此,我们通过采用相继的 convex近似技术,有效地解决优化问题。为弥补优化问题的高度复杂性,我们提出了一种低复杂性算法,其性能略有损失。在数字结果中,我们表明拟议的算法可以大大节省UAVE能源消耗量,而没有IRSs的基准则证明利用IRs确实有利于UAV能源消耗最小化。