Reliable auxiliary communication of UAV via relay cache optimization

Abstract

With the continuous reduction of drone costs and the miniaturization of equipment, many new applications have emerged in the civil and commercial fields. The remote sensing technology of Unmanned Aerial Vehicle (UAV) is used to manage and partition farmland accurately. Compared with the traditional field grid sampling method, UAV remote sensing technology can break through operating conditions, continuously collect data at low altitudes, monitor the area more flexibly, and significantly reduce labor and safety costs. Since UAVs can only provide data transmission services to users through wireless backhaul links established with ground base stations, the need to access the network is easy to lead to the disclosure of user privacy. The capacity of wireless backhaul links is limited, limiting the transmission rate of drones and reducing the user’s quality of service. Therefore, we apply edge caching technology to the assisted relay communication network to study the impact of caching technology on the performance of mobile relay systems. In particular, we propose the horizontal position design method in the buffer auxiliary relay single-user system, and the 3D position design method in the buffer auxiliary relay multi-user system. Position system, which can be reached by the maximum system average and the optimal speed, is designed. Besides, with the help of objective function conversion and classic derivation analysis method, the semi-closed expression of the optimal position of the UAV is obtained, and the intersection of the mobile relay end velocity and the user end velocity is used as the initial value. Meanwhile, the solution formula is substituted after continuous iteration so that the best advantage of local velocity can be obtained. In addition, mobile relay system is deployed to establish a two-hop wireless link to achieve reliable communication between Base Station (BS) and users security trust. The simulation experiment proves that compared with other methods, the method proposed in this paper has considerable performance improvement in power convergence, speed, trajectory path loss, and energy cost, which can provide higher-quality communication services for users in the system and better support for the broad application of drones.