Positioning Based on Retroreflection for Channel Estimation in Vehicular VLC

Visible light communications is considered a promising technology in 6G scenarios, specially, in those environments where traditional RF systems are complex to implement, e.g., vehicular or industrial. Furthermore, determining the position of vehicles or any other target becomes a requirement for the implementation of artificial intelligence solutions such as autonomous vehicles. In this work, we propose to exploit the deployment of retroreflectors and angular diversity receivers to determine the distance between vehicles. Specifically, the design of both elements is analyzed. After that, the measured distance is employed to estimate the channel state information (CSI) that feeds a transmit precoding scheme such as zero-forcing. Simulation results show that the proposed approach provides a satisfactory estimation of the distance between vehicles that allows us to apply complex signal processing techniques based on CSI without the need for dedicated pilots nor implementing a closed-loop data transmission scheme.