Towards System Level Simulation of Reconfigurable Intelligent Surfaces

Reconfigurable Intelligent Surfaces (RISs) have emerged as an essential technology for the next generation of wireless communication systems. They have the potential of improving system throughput, coverage, and energy efficiency. An RIS is a planar surface that consists of multiple reflecting elements with configurable phase shifts that can modify impinging signals and steer reflected waves in any direction. To evaluate the benefits of deploying RISs in future wireless networks, it is essential to conduct system-level simulations for RIS-aided large-scale multi-cell networks. Thus, a reliable system-level simulator is in urgent need. This paper introduces an extension for RIS-aided transmission for the Vienna 5G system-level simulator. Most of the system-level concerns for RIS-based wireless networks are addressed, such as RIS modeling, RIS phase shifts optimization, large-scale fading, small-scale fading, and cell association. In addition, the average system performance of the RIS-aided single-input single-output (SISO) scenario is evaluated through Monte-Carlo simulations and compared with known theory. Simulation results are compared between optimized and random RIS phase shifts. The results from the system-level simulator are consistent with the power scaling law for RIS. The SISO scenario performance verification is a stepping-stone for further system-level simulations in RIS-based multiple-input multiple-output (MIMO) scenarios.