Balancing Illumination and Communication in Indoor VLC: Impact of Multiple LED Configurations on System Performance

This study explores the influence of multiple luminaire arrangements on the dual functionality of visible light communication systems (VLC), focusing on their impact on illumination uniformity and communication performance. A comprehensive analysis of various luminaire distributions, ranging from single to multiple luminaires, is performed to identify configurations that optimize lighting quality and data transmission efficiency. In particular, the study examines three luminaire arrangements—circular, square, and circular-square—implemented in configurations of 1 to 12 luminaires, and includes theoretical modeling and experimental validation in indoor environments, covering single-input single-output (SISO), multiple-input single-output (MISO), and multiple-input multiple-output (MIMO) configurations up to $3 \times 2$ systems. Orthogonal frequency division multiplexing (OFDM) with repetition coding (RC) is employed, which distributes data across subcarriers while replicating signals across transmitters to enhance spatial diversity. Key performance metrics, such as illumination, uniformity, quality factor ( $F_{a}$ ), and coefficient of variation (CV(RMSE)), are evaluated for illumination, while communication performance is assessed using bit error rate (BER) metrics. The results demonstrate that the overall performance is improved as the number of luminaries increases, however a saturation point exists beyond which additional luminaires yield diminishing returns. Our findings highlight the complex interplay between illumination uniformity and communication performance in VLC systems, providing valuable insights for designing high-performance MIMO systems in smart indoor environments.