Non-line of sight visible light communications: A technical and application based survey

Visible Light Communication (VLC) do not suffer from electromagnetic interference and can be safely used in sensitive environments such as chemical plants, aircrafts and hospitals, as well as in high vehicle density VLC systems advantages of have high speed, greater power efficiency and a high spatial reuse ratio makes it a promising candidate for object allocation detection and V2V communication. This work review the need to assess the Non-Line of Sight propagation in VLC systems as the real applications have Line of Sight (LoS) and Non Line of Sight (NLoS) transmission. The challenges in VLC development and implementation are highlighted, and channel modelling of the NLoS VLC systems to ensure accuracy of channel capacity is discussed. Optimizing the configurations of VLC networks is important to overcome the challenges in VLC implementation and channel modelling. MIMO configurations in NLoS VLC systems coupled with suitable equalization techniques may be required to mitigate the high interference. BER, SNR and channel impulse response are some parameters that should be investigated to assess the performance of the NLoS VLC system.