Optimization of RIS-Aided MIMO Systems Via the Cutoff Rate

The main difficulty concerning optimizing the mutual information (MI) in reconfigurable intelligent surface (RIS)-aided communication systems with discrete signaling is inability to formulate this optimization problem an analytically tractable manner. Therefore, we propose use cutoff rate (CR) as a more metric for MI and introduce two methods maximize CR, assuming perfect knowledge of channel state (CSI). first method based on projected gradient (PGM), while second derived from principles successive convex approximation (SCA). Simulation results show that proposed significantly enhance CR corresponding MI.