Characterisation and Interference Model of Contemporary Artificial Light Sources Noise on a VLC channel.

Indoor visible light communication (VLC) has seen major growth in the last decade, reaching data rates in the Gbps range over 10 m distance. Its main limiting factors however are the low speed of the optoelectronic devices as well as the ambient noise reducing the system performance and reliability. The interference due to the artificial white light sources used for illumination in an indoor environment is one of the major noise sources challenging the performance of the VLC indoor channel. Since these noise sources operate at different frequencies, filtering their DC effect out does not eliminate their effect. This paper practically measures the noise power of the contemporary artificial light sources in an indoor visible light link to characterize their effect. The measurements show that thermal light sources cause a high noise power in a limited bandwidth of a few hundreds of Hz, while gas discharge lamps and dimmed semiconductor light sources have a much wider significant noise spectrum. An interference model to determine the overall noise power due to said sources is then deduced.