Abstract

This article addresses the problem of secure communication in an unmanned aerial vehicle (UAV)-aided wireless communication system in which a source sends confidential messages to a destination via an untrusted UAV mounted with a miniaturized energy-harvesting transceiver. The UAV can overhear the source’s confidential messages. To create a positive secrecy rate, the destination sends jamming signals during the communication. We aim to maximize the achievable secrecy rate for two scenarios: security-on-demand UAV (SoD-UAV), where the UAV can modify its trajectory and power-splitting (PS) ratio to serve the secure communication, and non-security-on-demand UAV (nSoD-UAV), where the UAV only forwards the source’s messages. For the nSoD-UAV, we optimize the transmit powers at the source and the destination for a given UAV’s trajectory and given PS ratios. For the SoD-UAV, the UAV’s trajectory, the PS ratios and the transmit powers are jointly optimized. Due to the non-convex optimization problems, we use successive convex optimization and block coordinate descent methods to find efficient approximate solutions. Numerical results verify that the achievable secrecy rate is significantly improved using the proposed algorithms.

中文翻译：

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具有无线信息和功率传输的不受信任的无人机辅助协作通信的保密容量最大化

摘要

本文解决了无人飞行器（UAV）辅助的无线通信系统中的安全通信问题，在该系统中，源通过安装了小型能量收集收发器的不受信任的UAV将机密消息发送到目的地。无人机可以窃听消息来源的机密消息。为了创建正的保密速率，目标在通信期间发送干扰信号。我们的目标是在两种情况下最大化可达到的保密率：按需安全型无人机（SoD-UAV），其中无人机可以修改其轨迹和功率分配（PS）比率以服务于安全通信；以及非安全性。按需UAV（nSoD-UAV），其中UAV仅转发源消息。对于nSoD-UAV，我们针对给定的无人机轨迹和给定的PS比优化了源和目标处的发射功率。对于SoD-UAV，联合优化了无人机的轨迹，PS比和发射功率。由于存在非凸优化问题，我们使用连续凸优化和块坐标下降方法来找到有效的近似解。数值结果证明，所提出的算法可以显着提高保密率。