Routing Design Of Mobile HAP And Joint Scheduling Of Power Supply And Information Transmission In WPCN

In recent years,with the development of wireless energy transmission technology,WPCN(Wireless Powered Communication Network)has become a research hotspot at home and abroad [1].Compared with traditional energy-constrained wireless sensor networks,the WPCN eliminates the need for network nodes to frequently recharge or replace batteries,which can provide higher network throughput,longer network lifetime,and lower network operating costs.However,WPCN still has the following problems:(1)Because the Wireless Energy Transfer(WET)and the Wireless Information Transmission(WIT)in the network are all sensitive to distance information,the "double near-far distance effect" and performance unfairness will be caused between network nodes in different locations.Therefore,it is necessary to design the charging strategy of the charging equipment and the mobile circuit;(2)In the WPCN,The HAP(Hybrid Access Point)performs WET and WIT on the Wireless Device(WD)in the same frequency band by Time Division Multiplexing(WMT).How to schedule the time slot of WET and WIT has important influence on the WPCN performance.Therefore,joint scheduling and overall optimization are needed to reduce interference and improve Network throughput and utilization efficiency.In view of the above problems,many scholars have done a lot of research in the fixed HAP scenario.In this paper,we mainly study how to overcome the unfairness of network performance and how to schedule and optimize WET and WIT to improve the throughput of the network when HAP can be moved.The main work of this article is as follows:(1)HAP can move to the target ends and charge them in turn according to the residual energy state of each network node.In this scenario,this paper comprehensively considers the energy consumption rate fluctuations and geographical distribution information of each network node,and proposes a density-based nested TSP(Travelling Salesman Problem,Traveling Salesman Problem)path optimization algorithm,and provides a solution to each node.The Optimal Path of HAP Move under Energy Constraints The simulation results show that compared with the existing path optimization algorithms,the proposed algorithm reduces the total network charge delay by at least 10%.(2)Under the premise of HAP energy transmission along the optimized mobile route,a novel fixed slot-based FSCF(Fixed Slot based Competition Free)method is proposed to optimize HAP and WET and WIT between various network nodes.Through simulation and verification,compared with the existing distributed scheduling method,the FSCF method can increase the network throughput by up to about 20%.Compared with the fixed HAP,the mobile HAP can flexibly operate according to the energy state of the network nodes and the transmission data requirements,so that it can better meet the needs of the network.The design of optimized HAP mobile route and joint optimization of energy transmission and information transmission are of great significance for improving the performance of WPCN network.