Research On WPCN Network Deployment Optimization Strategy Based On UAV-Enabled Relaying

In recent years,UAV(Unmanned Aerial Vehicle,UAV)technology is continu-ously improving,and the research system of Wireless Powered Communication Net-works(WPCN)is also constantly improving.The existing WPCN technology can solve the energy shortage problem of remote users,avoid frequent battery replace-ment operations,and can also reduce labor costs,and is particularly important in cer-tain scenarios where manual operations cannot be performed.Drone-assisted com-munication technology can solve the problem of poor communication links,and be-cause the UAV has good maneuverability,it can be adapted to various complex de-ployment scenarios.In the lack of communication resources and various emergency disaster relief fields,it is necessary to quickly build a communication foundation,of which stable working energy and effective information transmission are the prerequi-site guarantees for carrying out the work.Therefore,how to use drones to quickly build an auxiliary communication system based on WPCN has become a hot research topic.The main research problem of this thesis is the UAV-assisted relay communica-tion system based on WPCN,and for different application scenarios,two UAV de-signs are proposed,one is a dual UAV design,the other is a single UAV design design.In the case of sufficient resources,you can choose the dual drone design to work.Since the channel link of the UAV relay communication is limited by the distance between the UAV and the destination node,the UAV must be as close as possible to the destination node in the work,so as to ensure the user's service quality.The ad-vantage of the dual drone design is that it can give full play to the mobile characteris-tics of the drone,one of which is used for energy transmission and the other is used for relay communication.Advantage,and provide better QoS for target users.The single drone design uses only one drone,which can be quickly deployed in the work,with low cost,and low requirements for the communication spectrum resources of the drone.In the design scenario of this thesis,the drone is used to help forward the information of multiple source nodes(the source node is low power and there is no power supply)to the destination node when the communication channel is severely blocked.In order to support information transmission,the UAV is used to provide wireless energy transfer(Wireless Energy Transfer,WET)and information forwarding(Wireless In-fortmation Transfer,WIT)services to the source node.The goal of system optimiza-tion is to maximize the throughput of the drone.In the design of communication sys-tems that use drones as auxiliary relays in wireless energy-carrying communication networks,this thesis is divided into two models:dual drones and single drones.Based on the above,the main research contents and innovations of this article are summa-rized as follows:(1)Optimization strategy of dual UAV wireless energy-assisted auxiliary relay communication transmission:In the case of sufficient cost and resources,consider introducing two UAVs.When the user location of each source node is clear and the power consumption of the UAV is not considered,the UAV is used as a relay com-munication transmission platform to forward the information sent by each source node to the destination node.One of the unmanned aerial vehicles serves as a WET UAV,serving ground source nodes to transmit energy to ensure its normal operation;the other unmanned aerial vehicle serves as a WIT UAV,assisting the ground source nodes to forward the required information to the destination node.Through the con-tinuous convex approximation(SCA)algorithm and an iterative algorithm,the goal of maximizing the throughput of the drone is to use alternating optimization to solve the problems of optimal power allocation,user scheduling and optimal flight trajec-tory of the drone.Reduce the network cost while ensuring the minimum communica-tion requirements of the source node.The advantage of introducing two drones is that they can maximize the mobile advantages of drones to ensure the quality of service(QoS)of users.(2)Optimized transmission strategy of single UAV wireless energy-assisted relay communication:the optimization of UAV throughput is also taken as the optimization goal.On the one hand,due to the relevance of UAV information reception and trans-mission,the system is constrained by the causality of information;on the other hand,due to the correlation of energy collection and energy consumption,the source node is subject to the so-called fair causality constraint;in addition,Considering the access delay problem of all ground nodes,the system proposes two scenarios of delay toler-ance and delay sensitivity.However,the resulting problem is non-convex and it is difficult to obtain its optimal solution.In order to solve this problem,a continuous convex approximation method is applied,and a suboptimal solution can be achieved.Finally,the simulation results verify that the algorithm is reliable.And proposed a benchmark program,compared with the benchmark program,the optimization per-formance of the proposed algorithm is more effective.The use of integrated drones can reduce the cost of relays and increase the utilization rate of drones.