Research On Ultra-reliable Low-latency Communication Based On Drone-assisted Networ

With the popularization of the fifth-generation(5G)mobile communication technology,it has promoted the transition of Internet of Things(IoT)applications from traditional machine type communication to critical mission communication.However,such applications transmit shorter block length,which place stricter requirements on the reliability and delay of communication,making traditional wireless communication technologies difficult to apply.The Ultra-Reliable and Low-Latency Communication(uRLLC)technology adopts finite block length transmission,which provides an effective solution to the above challenges.In addition,wireless communication technology based on Unmanned Aerial Vehicles(UAVs)has advantages such as three-dimensional space height controllability,on-demand deployment,high network flexibility,and ease of establishing air-to-ground line-of-sight channels,and has been considered as a communicationassisted technology with huge application potential.When UAV-assisted communication technology is combined with uRLLC technology,more significant system advantages can be achieved.UAV-assisted communication technology can not only improve the flexibility of the uRLLC network and expand the network coverage,but the uRLLC technology,in turn,can promote the UAV-assisted communication network to be more precise and efficient.Therefore,how to promote the efficient combination of these two communication technologies is a major research hotspot.Considering the current application needs and technological development trends,this article mainly focuses on the following two aspects for research.(1)Research on the uRLLC communication mechanism based on UAV scheduling algorithm and Non-Orthogonal Multiple Access(NOMA)technology.Firstly,using the UAV as an airborne communication relay,a line-of-sight channel is established between the base station and the users to form a uRLLC network consisting of the base station,UAV,and users.The purpose is to minimize the overall error rate of the wireless communication process through UAV scheduling and Successive Interference Cancellation(SIC)technology to improve the system’s reliability.Secondly,based on improving reliability,the optimal solution for UAV resource allocation in the downlink is proposed,and the global optimal solution for power control and block length allocation is discussed.Finally,under the same power and block length conditions,the system performance of the proposed communication scheme is verified through simulation.(2)This study focuses on the joint optimization mechanism of power control,resource allocation,and UAV deployment location in a multi-UAV-assisted uRLLC network.In the case where the base station is not available or difficult to deploy,a communication network that utilizes UAV base stations to serve IoT devices is proposed.The goal is to reduce the average uplink transmit power of IoT devices through joint optimization of device scheduling,resource allocation,and UAV deployment location.This optimization is a non-convex problem and cannot be solved by conventional convex optimization methods.To obtain the optimal solution to the original problem,an efficient iterative algorithm is proposed by Block Coordinate Descent(BCD)method and Lagrange Dual Decomposition(LDD)technique.The feasibility and effectiveness of the proposed algorithm are verified through simulation.