Optimized LED Layout and Reflection Suppression for Robust Indoor Visible Light Positioning System

Visible Light Positioning (VLP) systems offer a promising solution for indoor positioning due to their high precision, low cost, and energy efficiency. However, multipath effects, where light signals reflect off walls, furniture, and other obstacles, cause significant degradation in positioning accuracy. This paper addresses these challenges by investigating the impact of multipath reflections on VLP systems and proposing an effective solution that combines LED layout optimization and reflection suppression. The study begins by demonstrating that concentrating all LED lights at the center of the room minimizes the impact of wall reflections on ranging performance. However, this configuration leads to poor Geometric Dilution of Precision (GDOP), causing amplified errors in the final localization. To address this issue, this paper presents an optimization algorithm that identifies the optimal LED layout, considering reflections, channel noise, and GDOP, to improve overall localization accuracy. Furthermore, a robust reflection suppression method is developed that leverages phase information from two adjacent LEDs to estimate the line-of-sight signal strength. This method effectively reduces the impact of reflected signals without requiring explicit modeling of reflective surfaces, significantly enhancing the adaptability of VLP systems in indoor environments. Simulation results demonstrate that the proposed system reduces the average positioning error from 23.63 cm to 5.79 cm, significantly outperforming conventional VLP approaches. These results confirm the effectiveness and adaptability of the proposed framework in addressing the multipath problem and advancing the practical deployment of high-precision indoor positioning systems.