Performance-driven visible light sensor for indoor georeferenced positioning

This paper presents the design and performance evaluation of a visible light sensor tailored for transmitting georeferenced information from light-emitting lamps. A detailed analysis of the IEEE 802.15.7 visible light communication (VLC) standard protocol is carried out, followed by the design and description of a novel custom communication protocol specifically optimized for this application. Unlike existing solutions, which often rely on external databases for georeferenced data retrieval, the proposed protocol enables real-time transmission and localization of information directly through the VLC channel, eliminating the need for additional infrastructure and reducing system complexity. A comparative analysis of theoretical simulations for widely used modulation schemes, including On-Off Keying (OOK), Orthogonal Frequency Division Multiplexing (OFDM), Binary Phase Shift Keying (BPSK), and Frequency Shift Keying (FSK), was conducted in terms of Bit Error Rate (BER) across varying CNR conditions. The findings indicate that BPSK and FSK offer the best trade-off between implementation simplicity and noise resilience, with BPSK demonstrating superior performance, particularly in scenarios with high noise levels. Conversely, FSK emerges as a viable, low-cost alternative for moderate-noise environments. Experimental tests with light-emitting diodes (LEDs) of different wattage ratings provided insights into the system’s practical performance under real-world conditions, validating theoretical and simulation results. By integrating LEDs of varying wattages into the evaluation process, this study highlights the system’s adaptability to different light sources and noise conditions.