Abstract
Localization or Location-based services using Electromagnetic spectrum has attracted many researchers in recent years. Considering the current era, the most trending domain is Wi-Fi. The radio spectrum is being congested due to enormous data traffic load, which is called "Spectrum Crunch". Consequently, designation of Wi-Fi signals may be carcinogenic and it's been reported by WHO (World Health Organization). To address this issue, a short range wireless communication based on light illumination from LED' which has been introduced recently. This new technology is called Light-Fidelity (Li-Fi). Which is considered as a green technology that comes up with more ecologically & economically friendly solutions. The edge of using Li-Fi over Wi-Fi for localization is; generally there are many more LED luminaries in a building in comparison to the number of Wi-Fi AP's, which is cost effective. There is now developing of interest in all over the World including; within the bodies' such as the Wireless world Research Forum (WWRF) and the Visible Light Communications Consortium (VLCC).
In this paper, we outline the basic light system and its modulation techniques; Li-Fi' specific in the indoor environment, review the state of art and discuss appropriate physical layer modulations schemes in the context of indoor localization.