Energy Saving Ability for LED Ring Alignments with Optimized LED SAHPs in Dimming Visible Light Communications

In order to evaluate the energy saving ability of the visible light communications (VLC) system, we employed optimizations with different parameters for two LED alignments. We choose SC-4PPM modulation scheme to implement the dimming control. By minimizing energy efficiency, with respect to LED semi-angle at half power (SAHP) and LED position parameter, along with modulation parameters b and c, in the condition of maintain communication and lighting requirement, we obtained optimal energy efficiency. The results show that, the energy saving can be improved above 30% over the non-optimized (NOP) situation, for both the LED ring alignment and LED ring-corner alignment.