Analysis of energy saving ability in dimming VLC systems using LEDs with optimized SAHP

•The potential of LED SAHP oriented system parameters to enhance VLC energy efficiency is investigated.•Four LED alignments of the same total LEDs are deployed and their performances are compared.•Types of optimizations are designed to gain better tradeoff between efficiency and SNR variations.•VLC with narrow SAHP LEDs can save more than 40% energy consumptions compared to the traditional dimming situation.

In this paper, we investigate the energy saving capability of dimming visible light communication (VLC) systems employing SC-4 PPM modulation scheme. We design different optimizations to maximize the energy efficiency according to the different illuminance efficiency with respect to LED's semi-angle at half power (SAHP) for four different LED alignments. Tradeoff between energy efficiency and signal-to-noise ratio (SNR) uniformity are also investigated to achieve better overall performance. The results show that more than 40% energy can be saved over the existing dimmed VLC system employing SC-4 PPM modulation scheme when optimized SAHP LEDs are used.