Research On The Resource Allocation Of SWIPT-enabled UAV Communication System

The popularization and application of the internet of things(Io T)technology has prompted the explosive growth of Io T devices,which has led to the higher requirements for the traditional wireless communication network.On the one hand,due to the limited battery life of the Io T devices,it is necessary to improve the endurance of Io T system while ensuring the quality of service(Qo S)for the Io T devices.On the other hand,with the massive access of the Io T devices,the problem of energy consumption will become serious.Therefore,it is urgent to enhance the energy efficiency(EE)of the internet of things communication system.Simultaneous wireless information and power transfer(SWIPT)technology,which can realize the simultaneous transmission of wireless information and energy,is able to extend battery life of Io T devices.However,when Io T devices are deployed in remote areas or disaster areas,it is inefficient to establish communication links with traditional base stations(BSs)due to long-distance transmission.Owning to the advantages of great maneuverability,wide coverage,and high flexibility,unmanned aerial vehicle(UAV)can quickly serve the Io T devices which are difficult to be covered by traditional BSs.Furthermore,UAV communication can be used to complement the traditional SWIPT system while providing services for Io T devices with great channel conditions.Therefore,the combination of UAV communication and SWIPT technology has great application prospect.In this work,we first study the resource allocation algorithm of UAV-assisted SWIPT system,and study the energy efficiency(EE)optimization problem of device-to-device(D2D)communications underlaying UAV-assisted SWIPT system based on the above system.The main work content and research results are summarized as follows:1.The joint resource allocation problem of multi-UAV-assisted SWIPT system has been researched.Firstly,we build an Io T communication system where the UAVs transmit information and energy simultaneously to the Io T devices.On this basis,an optimization problem that aims to maximize the minimum average transmission rate of the Io T devices is proposed.Since the optimization problem involves multiple coupled variables and 0-1 integer variables,the proposed optimization problem is a mixed integer non-convex optimization problem,which is difficult to be solved in a limited polynomial time.Thus,we propose the joint resource allocation algorithm based on the successive convex approximation(SCA)technique.Finally,the simulation results prove the convergence and effectiveness of the proposed algorithm,and verify that the UAV-assisted SWIPT system has advantages in improving the transmission rate of the Io T system.2.The D2 D communications underlaying UAV-assisted SWIPT system based on the above research has been studied to maximize the EE of the system.In order to further improve spectrum utilization efficiency and channel gain,we apply the beamforming and non-orthogonal multiple access(NOMA)communication technology to improve transmission performance.Firstly,we build an D2 D underlaying UAV system where an UAV equipped antenna array to transmit information and energy to the Io T devices.On this basis,we aim to maximize the EE of the system while satisfying the constraints of transmission rate and transmission power budget.However,the proposed problem is non-convex involving joint optimization of the UAV location,beam pattern,power control and time scheduling,which is difficult to tackle directly.In order to solve this problem,we develop the joint UAV location and resource allocation algorithm based on the SCA and multi-objective evolutionary technique.The simulation results verify that significant EE gain can be obtained by our proposed algorithm as compared to the benchmark schemes,and it is proved that the combination of beamforming,NOMA and D2 D communication technology has certain advantages over traditional solutions in improving EE.