Illumination, communication and energy efficiency analysis of indoor visible light communication systems under the influence of optical source emission characteristics

The effective illumination and data transmission capabilities of visible light communication (VLC) depend on the various emission characteristics of optical sources. The mathematical modeling and simulation of the indoor VLC over the illumination sources with different radiation patterns are presented in this paper. The performance analysis for the optical sources with Lambertian, Lambertian directional, Batwing and Gaussian radiation patterns is carried out in the aspects of illumination, communication and energy efficiency. The illumination analysis results that the Lambertian and Batwing sources can provide flat illuminance in communication plane than the other sources due to their greater illuminance uniformity. The communication ability of the diverse sources is analyzed with the distribution of optical power and RMS delay, and achievable data rate. The Lambertian and Batwing sources provide better user mobility as they have uniform optical power distribution, and they can provide 812 Mbps and 908 Mbps, respectively. The Lambertian directional and Gaussian sources have the optical power concentrated in some regions of indoor environment, and they can provide the 1.082 Gbps and 794 Mbps, respectively, in those regions. This makes these sources more suitable for the fixed VLC links. The energy efficiency of the Lambertian directional source is 108.2 Mbps/W, and its order of emission and directivity makes it more energy efficient than the other sources. The other source emission characteristics such as spectral power distribution curves and correlated color temperature are investigated. Based on all these analyses, the appropriateness and associated safety levels of optical sources in distinct VLC environments are proposed.