V2X Visible Light Communication Using an LED Bar and a Rolling Shutter Image Sensor: A Demodulation Method with Complementary use of Raw and Processed Images for Long-Range and High-Speed Mobile Environments

This paper introduces a long-range visible light communication system adaptable to high-speed mobile environments, based on an LED bar and a rolling shutter image sensor. Prior work [1] faced challenges regarding communication distance and accuracy during mobility. To address these issues, we modified the signal processing method and introduced a novel demodulation algorithm. This algorithm complementarily leverages the raw received image and its processed counterpart to realize highly noise-resistant demodulation, a task challenging for simple binarization methods. The effectiveness of the proposed approach was verified through outdoor experiments in both static and mobile environments. The results demonstrate that in static scenarios, no errors were observed at distances up to 125 m, surpassing prior work, and the system showed robust performance with no significant degradation in rainy weather. Furthermore, in mobile experiments, we successfully sustained communication with no detected errors even at high speeds of 120 km/h. These findings indicate that the proposed system offers high reliability in both long-range and dynamic V2X environments.