A trajectory optimization method for UAV cascade relay broadcast communication system

无人机级联中继广播通信系统航迹优化方法

Tianjin Key Lab for Advanced Signal Processing, Civil Aviation University of China, Tianjin 300300, China

Received: 7 July 2022

Abstract

An unmanned aerial vehicle's(UAV) trajectory optimization is an important way to improve the performance of its relay communication system. The trajectory optimization method for the UAV cascade relay broadcast communication system that uses the decoding and forwarding protocols is studied. Firstly, the expressions of the signal-to-noise ratio of the UAV and the user are given. Then, a joint trajectory optimization method and a distributed trajectory optimization method for cascaded UAVs based on the minimized maximum user interruption probability are proposed. The transmission performance of the system link that uses the two trajectory optimization methods is studied; the mathematical expressions of the relay communication system's traverse capacity and the outage probability of a single user are given. Finally, the influence of the relay communication system's characteristic parameters on the optimal trajectory of the cascade relay UAV and its performance are verified with computer simulations. The simulation results show that the performance of the two trajectory optimization methods is basically the same, thus verifying the effectiveness of the trajectory optimization criterion.

摘要

无人机航迹优化是提高无人机中继通信系统性能的重要方式之一。针对无人机级联中继广播通信系统, 研究其在译码转发协议下的航迹优化方法。分析给出了无人机和用户的信噪比表达式, 在此基础上提出了基于最大用户中断概率最小化准则的级联无人机航迹联合优化方法和分步优化方法, 研究了2种航迹优化方法下系统链路的传输性能, 给出了系统遍历容量和单个用户中断概率的数学表达式。通过计算机仿真分析验证了系统特征参数对级联中继无人机最优航迹和系统性能的影响。仿真结果表明: 所提2种航迹优化方法性能基本一致, 验证了航迹优化准则的有效性。