This article investigates the use of unmanned aerial vehicles (UAVs) in assisting hybrid non-orthogonal multiple access (NOMA) systems to enhance spectrum efficiency and communication connectivity. A joint optimization problem is formulated for UAV positioning and user grouping to maximize the sum rate. The formulated problem exhibits non-convexity, calling for an effective solution. To address this issue, a two-stage approach is proposed. In the first stage, a particle swarm optimization algorithm is employed to optimize the UAV positions without considering user grouping. With the UAV positions optimized, a game theory-based approach is utilized in the second stage to optimize user grouping and improve the sum rate of the hybrid NOMA system. Simulation results demonstrate that the proposed two-stage method achieves solutions close to the global optimum of the original problem. By optimizing the positions of UAVs and user groups, the sum rate can be effectively improved. Additionally, optimizing the deployment of UAVs ensures better fairness in providing communication services to multiple users.

中文翻译：

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无人机辅助混合NOMA系统的无人机位置和用户分组联合优化

本文研究了使用无人机 (UAV) 协助混合非正交多址 (NOMA) 系统提高频谱效率和通信连接性。针对无人机定位和用户分组制定了联合优化问题，以最大化总速率。所提出的问题表现出非凸性，需要有效的解决方案。为了解决这个问题，提出了一个两阶段的方法。第一阶段，采用粒子群优化算法来优化无人机位置，而不考虑用户分组。随着无人机位置的优化，第二阶段采用基于博弈论的方法来优化用户分组，提高混合NOMA系统的总和率。仿真结果表明，所提出的两阶段方法获得了接近原始问题的全局最优解。通过优化无人机和用户群体的位置，可以有效提高总和率。此外，优化无人机的部署可以确保为多个用户提供通信服务时更加公平。