基于虚拟三维环境的海上移动空中基站部署方法

The maritime communication network is an important infrastructure to support the marine strategy, by using which there is still a blind area of broadband information coverage at sea. The reason is that mobile communication networks, such as 4G and 5G, focus on land scenes, with limited coverage range at sea, and the communication rate of the maritime satellite system is limited due to resource constraints such as the spectrum and the orbit position. In this project, by using the characteristics of vessels’ distribution and the communication environment, the on-demand coverage method of mobile aerial base station at sea is studied. Unlike shore-based base stations and satellites, mobile aerial base stations can be agilely deployed. However, due to the dynamic changes of the maritime environment and the sparse distribution of vessels on the vast sea, the deployment of mobile aerial base stations at sea faces different challenges from land scenes: the deployment takes a long time and it is difficult to obtain channel parameters. This project studies the channel estimation method based on the virtual three-dimensional environment with the prediction method and the analytic hierarchy process, by using the route information of vessels and the predicted environmental data, so as to obtain the channel state information with low computational cost and high accuracy for deploying the mobile aerial base station in advance. Furthermore, by exploring the coexistence mechanism of shore-based base stations, mobile aerial base stations and satellites, the adaptive selection of the backhaul link of the mobile aerial base station based on virtual channel estimation is studied to realize the communication parameter configuration of mobile aerial base station and the route planning of UAVs from the perspective of integrated network.

海上通信网络是支持国家海洋战略的重要基础设施。现有海上通信网络仍存在宽带信息覆盖盲区。原因为4G、5G等移动通信网络以陆地场景为主，海上覆盖范围受限；海事卫星系统由于频谱、轨位等资源约束，通信速率受限。本项目结合海上用户分布和传播环境特征，研究海上移动空中基站按需覆盖方法。与岸基基站和卫星不同，移动空中基站可以机动部署。但海面等海上环境动态变化，且船舶在浩瀚海上稀疏分布，海上移动空中基站部署面临与陆地场景不同的挑战：部署耗时长且获取信道参数难。本项目利用海上船舶的航线信息，结合大气和海水相关数据可预测的特点，分别采用预测法和层次分析法，研究低计算量、高准确性的基于虚拟三维环境的信道估计方法，为移动空中基站预先部署提供信道状态信息。进一步探索岸上基站、移动空中基站和卫星共存机制，研究基于虚拟信道估计的空中基站自适应回传方法，实现一体化网络视角下移动空中基站通信参数配置和无人机航迹规划。

海面等海上环境动态变化，且船舶在浩瀚海上稀疏分布，海上移动空中基站部署面临与陆地场景不同的挑战：部署耗时长且获取信道参数难。因此，本项目围绕研究内容（1）基于虚拟三维环境的信道参数预测方法、（2）基于虚拟三维环境的信道参数层次化估计方法、（3）基于虚拟信道估计的空中基站自适应回传方法开展研究工作，着重研究移动空中基站的预先部署。在项目执行期间，针对海上环境不断变化，获取预先部署移动空中基站所需信道状态难的问题，提出了基于虚拟三维环境的信道参数预测方法，得到适应海上环境变化的信道预测方法；利用三维Gerstner模型描述海面运动，利用射线追踪法分析了海面随机运动、空间分辨率对多径数量、路径损耗的影响，仿真结果表明海上以高概率出现两径传输，且概率受到空间分辨率影响；提出了面向船上用户的空中基站和船载基站协同覆盖方法，将船上用户作为通信服务对象，联合优化船上用户网络选择、功率分配和无人机位置，提高了船上用户的通信速率；提出了面向周期性任务的切换方法，结合周期性任务特点，利用设备的存储能力换取低切换时延，实现船舶在地面移动通信网络和卫星通信网络间的无感切换。