VLC system analysis in indoor environments: an integrated illumination and communication approach

Abstract

This thesis analyzes Visible Light Communication (VLC) systems for indoor environments, focusing on the integrated evaluation of illumination and communication performance. With increasing Radio Frequency (RF) spectrum demand, VLC systems utilize the unregulated visible spectrum (380-750 nm) for dual-functionality applications that provide both lighting and data transmission capabilities. The research establishes an integrated evaluation framework combining SolidWorks APEX optical ray tracing with MATLAB channel modeling, achieving 94% correlation between simulation platforms. This methodology enables systematic analysis of illumination uniformity and communication reliability across progressive system configurations, from Single-Input Single-Output (SISO) baseline implementations to MultipleInput Multiple-Output (MIMO) architectures incorporating angular diversity and cooperative techniques. Analysis reveals that illumination uniformity directly influences communication performance by minimizing signal strength variations and enhancing link stability. Luminaire distribution strategies significantly affect both illumination patterns and communication coverage. The circular-square arrangement achieves illumination uniformity of 0.75 and channel quality factor (𝐹a) of 4.74, demonstrating improved performance compared to conventional square and circular patterns. Experimental validation shows that MIMO implementations (2×2, 3×2, 4×2) achieve Bit Error Rate (BER) values of approximately 10−4 at 2-meter distances while maintaining illumination levels above 300 lux. Cooperative relay configurations provide 10% improvement in optical power reception. Angular diversity implementations at 30° enhance coverage uniformity with acceptable communication performance. Optical collectors with novel coupling structures achieve 5.3× experimental optical gain (8.8× simulated), improving receiver sensitivity and communication reliability. The analysis establishes quantitative relationships between illumination, uniformity, luminaire positioning, and communication performance, providing design guidelines for VLC systems that meet both lighting standards and data transmission requirements in indoor environments.