Ray-Tracing Based Algorithms for Indoor RIS Optimization and Coverage Enhancement

Reconfigurable Intelligent Surfaces (RISs) represent a key emerging technology in wireless communication systems, allowing for precise control over previously uncontrolled propagation environments. This paper investigates the integration and optimization of RISs to enhance coverage in indoor environments using NVIDIA's Sionna Ray-Tracing (RT) tool. The RIS is modeled as an array of reflective tiles with adjustable phase profiles. We analyze two phase profile approaches (gradient-based and distance-based) for steering reflected signals toward blind zones identified in the transmitter-only coverage map. Based on the fixed positions of the transmitter and RIS, we propose a clustering-based algorithm to determine sub-optimal target positions, focusing on the least covered areas in the transmitter-only coverage map. Additionally, we introduce a ray-tracing-based search algorithm to provide insights into a sub-optimal RIS size. Simulation results demonstrate that the proposed methods effectively enhance signal coverage and minimize blind zones, confirming their viability for real-world implementations in RIS-assisted communications.