Resource Optimization And Performance Analysis Of UAV Relay Communication System

Mobile networks have higher and higher requirements for latency,transmission rate,bandwidth and connection density.Connecting to the Internet has also become one of the important requirements for smart devices.With the development and popularization of smart devices and artificial intelligence,there are more and more devices that need to be connected to wireless networks.Moreover,the scope of application is becoming wider,and the application scenarios are becoming more complex.Resources are becoming tight to meet such a large number of terminals,and it is difficult to meet new application scenarios for traditional wireless communication.UAVs are suitable for using in new mobile networks,and can supplement existing communication networks in some special scenarios because of the deployment of UAVs is flexible.At the same time,an important application direction of UAV-assisted communication is emergency rescue.Therefore,this paper first analyzes the performance of the UAV relay communication system from the perspective of outage probability,and then combines the Ultra-Reliable and Low-Latency(URLLC)with UAV relay communication and studies the resource optimization problem of the UAV relay communication system to improve the performance.Finally,the application of UAV relay is demonstrated.The above three parts specifically include:(1)As for the performance analysis of the UAV relay communication system,the difference of the channel conditions between the air-ground and the ground-ground system is considered,and the probability that the large-scale fading is line-of-sight(Lo S)fading is calculated according to the elevation angle of the direct link.The probability density function of the small-scale fading is also considered.The density function is used to study the influence of the outage threshold,UAV position,altitude,relay transmission power and other factors on the outage probability of UAV relay system,which the UAV relay works in the state of amplifyand-forward and decode-and-forward.(2)As for the resource optimization problem of the UAV relay communication system,the joint optimization of time,bandwidth and UAV location in a two-way UAV relaying system with the URLLC requirements has been studied.The average communication rate of the backward link has been maximized under the URLLC constraint of the forward link.An effective low-complexity iterative algorithm has been proposed to solve the optimization problem alternately for the URLLC-enabled two-way UAV relaying system.(3)As for the performance measurement and application of the UAV relay communication system,a UAV is used to carry the communication node and build a simple UAV relay communication system.The source node is placed in the laboratory,the relay node is placed on the UAV,hovering at a fixed position and the destination node is placed in different locations in the campus.Then we measure the influence of destination node location,antenna type and relay transmission power on average communication rate respectively.Finally,a network camera is applied to the relay network to realize wireless remote video surveillance.