Research On Energy Efficiency Optimization Of UAV Assisted Backscatter Communication System

Backscattering technology,with its advantages of low power consumption,low complexity and low cost,is considered to be one of the core technologies of the future Internet of Things.However,the backscattering technology is affected by short communication distance,dual Near–far problem problems,etc.Unmanned aerial vehicle assisted communication technology is considered to have enormous application potential in future wireless communication scenarios due to its advantages such as high mobility and high probability line-of-sight channels.This article studies a drone assisted backscatter communication system,using a rotating wing drone equipped with a carrier transmitter and signal receiver to collect data from the backscatter device(BD).BD collects energy from the carrier signal and transmits data to the drone by reflecting the incident carrier signal.The limited energy of the drone battery is a key factor in the design of the system.Therefore,this article mainly focuses on the energy efficiency of unmanned aerial vehicle assisted backscatter communication systems.Research on resource allocation and trajectory optimization of unmanned aerial vehicle assisted backscatter communication systems in user mobile scenarios.Aiming at the problem of energy efficiency optimization in user mobile UAV assisted backscatter communication system,the objective function of maximum energy efficiency is established by optimizing BD scheduling,UAV transmission power and UAV trajectory,and an optimization algorithm based on Dinkelbach algorithm,Block coordinate descent algorithm and Successive convex approximation technology is proposed.The Dinkelbach algorithm transforms the original nonlinear fractional optimization problem into an equivalent integer optimization problem;The block Coordinate descent decomposes the equivalent integer optimization problem into three subproblems to deal with the coupling between variables;The successive convex approximation technology is used to approximate the non convex subproblems of trajectory optimization.The experimental results show that the proposed scheme can effectively improve energy efficiency compared to the hovering scheme of unmanned aerial vehicles and the separation scheme of carrier transmitters.Research on the optimal energy efficiency of unmanned aerial vehicle assisted backscatter communication systems in non orthogonal multiple access(NOMA)communication scenarios.For the optimization of system energy efficiency in NOMA communication scenarios,the optimal value of transmission power is first set based on the relationship between system energy efficiency and drone transmission power.Secondly,derive a closed form solution for the reflection coefficient based on the reflection coefficient subproblem.Then,the optimal flight speed is derived using the drone flight energy consumption model,and the optimal trajectory and reflection coefficient optimization problems are solved using alternating optimization.The experimental results show that compared to the NOMA communication scenario and rate optimization scheme,the proposed scheme can effectively improve energy efficiency.