Joint UAV Trajectory and STAR-RIS Optimization for STTR Maximization in Dynamic NOMA Networks

Chuang Deng, Dong Qing, Zhi Li, Mou Liang, Jialun Wan

With the advancement of wireless communication technology, the demand for data transmission speed continues to increase. This paper investigates an unmanned aerial vehicle–assisted nonorthogonal multiple access network integrating simultaneous transmitting and reflecting reconfigurable intelligent surface (STAR-RIS), in which a cascaded channel model is developed for base station–to–ground user equipment and base station–to–low Earth orbit satellite links. A joint optimization framework is proposed to maximize the system traversal total rate (STTR) through dynamic coordination of STAR-RIS energy splitting ratios and unmanned aerial vehicle 3D trajectory. The analysis quantifies STTR variations with STAR-RIS element counts, channel states, and ground user equipment communication requirements. Simulations validate the framework's effectiveness, demonstrating 64.2% STTR improvement over a system with no optimization and underscoring its potential in next-generation wireless communications.