A RIS-enabled Hybrid-color Real-time Light Backscatter Communication System

Visible light backscatter communication (VLBC) is an emerging Internet-of-Things (IoT) solution that leverages distributed light-emitting diode (LED) to provide high spectral efficiency and low-power communication services. However, practical scenarios often suffer from interference caused by external light sources, leading to severe link blockages. To address this challenge, we propose a novel hybrid-color VLBC system enabled by embedded reconfigurable intelligent surfaces (RIS), a promising sixth-generation (6G) candidate technology, to enhance channel quality and improve wireless communication performance. The proposed system employs a controllable RIS consisting of a liquid crystal modulation switch and an information-carrying tag to control the optical link radiated by the red-green-blue-yellow (RGBY) LED. By implementing embedded optimization algorithms, mixed light illumination parameters and relative spectral power distribution are adjusted to achieve superior color rendering and enhanced overall system anti-interference capabilities. Furthermore, we conducted an overhead analysis to evaluate the computational complexity introduced by reflective losses and hybrid-color optimization. Experimental results demonstrate that hybrid-color optimization achieves severalfold performance improvements, while the RIS-enabled system requires additional signal compensation. By implementing embedded algorithms, the proposed system maintains computational efficiency and rapid signal stabilization while achieving a practical balance between improved spectral efficiency and acceptable processing latency, making it suitable for latency-bounded, low-rate IoT communication scenarios.