Optimization of RIS-aided MIMO Systems via the Cutoff Rate

Stefan Nemanja (1) , Marco Di Renzo (2, 3, 4) , L N Tran (1) , M F Flanagan (1)

1 UCD - University College Dublin [Dublin]
2 Université Paris-Saclay
3 L2S - Laboratoire des signaux et systèmes
4 CNRS - Centre National de la Recherche Scientifique

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

Domaines: Electronique

Stefan Nemanja, Marco Di Renzo, L N Tran, M F Flanagan. Optimization of RIS-aided MIMO Systems via the Cutoff Rate. IEEE Wireless Communications Letters, 2021, ⟨10.1109/lwc.2021.3077579⟩. ⟨hal-03358335⟩