Design and experimental demonstration of multi-colour WDM based VLC system with angular diversity receiver

Abstract

This paper presents the design, theoretical formulation, and experimental demonstration of a compact, filter-free multicolour visible light communication (VLC) system using an angular diversity receiver (ADR). By leveraging the intrinsic wavelength selectivity of commercially available integrated red, green and blue (RGB) photodiodes (PDs) coupled with analogue-domain equal gain combining (EGC), the proposed ADR design eliminates bulky colour-separation optics whilst providing concurrent spatial diversity. The system’s link feasibility is theoretically and empirically established through a power budget analysis, confirming sufficient hardware voltage margins for reliable communication under realistic indoor ambient lighting conditions. Operating on a resource-constrained microprocessor, the prototype achieves an aggregate data rate of 3 Mbps across RGB channels with robust resilience against spectral crosstalk. Concurrent real-time transmission of environmental sensor data successfully verifies the feasibility and practical deployment value of this small-form-factor wavelength division multiplexing (WDM)-ADR architecture for indoor Internet-of-Things (IoT) networks.