无人机辅助的非正交多址反向散射通信系统能效优化算法

Energy Efficiency Optimization Algorithm for UAV-assisted NOMA-based Backscatter Communication Systems

无人机、NOMA和反向散射通信相结合,是物联网低功耗需求的有效解决方案。本文通过优化无人机发射功率、反向散射系数和飞行轨迹达到系统能效最优,首先设定发射功率最优值;其次基于反射系数子问题推导出反射系数闭式解,然后推导无人机最低飞行能耗速度,并采用二次变化算法求解简化的飞行轨迹子问题;最后设计基于系统吞吐量最优的无人机轨迹优化方案来对比,表明本文所设计方案较有优势且具有良好的算法收敛性。

The combination of drones,NOMA,and backscatter communication is an effective solution to the low power consumption requirements of the Internet of Things.This article achieves the optimal system energy efficiency through the transmission power,backscatter coefficient,and flight trajectory of drones.Firstly,the optimal value of transmission power is set;Secondly,based on the reflection coefficient subproblem,a closed form solution for the reflection coefficient is derived.For the drone flight trajectory subproblem,the minimum flight energy consumption speed of the drone is first derived.Based on this speed,the flight trajectory subproblem is simplified,and then the quadratic variation algorithm is used to solve the simplified flight trajectory subproblem;Finally,a drone trajectory optimization scheme based on the optimal system throughput was designed for comparative,indicating that the proposed scheme has advantages and good algorithm convergence.