Evolutionary algorithm-based optimisation of the signal-to-noise ratio for indoor visible-light communication utilising white light-emitting diode

Visible-light communication system that utilises white light-emitting diode (LED) lighting equipment has been proposed and expected to provide uniform wireless communications and illumination simultaneously. Owing to multipath transmission channel characteristics, up to now, it is still challenging to obtain uniform signal-to-noise ratio (SNR) for each position within the indoor environment. In this study, an evolutionary algorithm (EA)-based alternative scheme is proposed to optimise the SNR distribution for indoor visible-light communication systems. Presented analysis shows that in three distributed lighting configurations, when the optical powers of individual white LED lighting equipment are dynamically controlled by tailored EA, the dynamic range of SNR referenced against the peak SNR can be reduced by up to about 24.7% whereas the uniformity illuminance ratio is improved from less than 0.63 to over 0.70 with the impact to root-mean-square delay spread is negligible. Furthermore, the relationship between the field of view of receivers and the optimisation performance is presented as well.