NOMA-Enabled RIS-Assisted SATINs Under Multi-objective Optimization: A Deep Reinforcement Learning Approach
摘要
Satellite-aerial-terrestrial integrated networks (SATINs) with reconfigurable intelligent surface (RIS) and non-orthogonal multiple access (NOMA) are promising for next-generation communications due to their ability to intelligently reconfigure transmission environments and improve spectral efficiency, but face the tricky challenge of multi-objective optimization of network performance in dynamic communication environments. To better describe the model, a multi-vector optimization problem (MVO) is proposed to improve system reachability under many constraints, considering UAV energy, transmit beamforming, and RIS phase-shift. Real-time interaction with the environment is achieved with DRL algorithms, using multi-vector deep deterministic policy gradient (MV-DDPG) to find a suboptimal solution. Experimental results show an effective adjustment of the optimal update policy when considering three objectives simultaneously and different weighting settings.