多小区毫米波系统中无人机基站飞行姿态优化及性能分析

为了提高多小区毫米波系统中无人机基站覆盖区域内用户的通信质量，本文提出了一种无人机基站的飞行姿态优化方案。该方案首先在无人机基站天线数量趋于无穷大的情况下对吞吐量进行优化，得到最大吞吐量的渐近表达式，然后将吞吐量优化问题进一步细化为天线倾斜角优化问题，最后通过穷举搜索算法来获得使吞吐量最大的天线阵列倾斜角，进一步通过调整天线倾斜角以优化无人机飞行姿态。数值仿真结果表明，所提出的优化方案能够有效提高系统性能，对于多小区无人机毫米波通信系统的性能优化具有理论指导意义。 

Flight attitude optimization of UAV base station and performance analysis in multi-cell millimeter wave system

In order to improve the communication quality of users in the coverage area of UAV base station in multi-cell millimeter wave system, a flight attitude optimization scheme of UAV base station is proposed in this paper. In this scheme, the throughput is optimized when the number of UAV base station antennas tends to infinity, and the asymptotic expression of the maximum throughput is obtained, and then the throughput optimization problem is further refined into the antenna tilt angle optimization problem. Finally, the antenna array tilt angle to maximize the throughput is obtained by exhaustive search algorithm, and the UAV flight attitude is optimized by adjusting the antenna tilt angle. Numerical simulation results show that the proposed optimization scheme can effectively improve the system performance and has theoretical significance for the performance optimization of multi-cell UAV millimeter wave communication system.