Multiuser Access in LiFi using OFDMA

Abstract

Light Fidelity (LiFi) is an emerging optical technology for wireless data access in short range communication to complement WiFi, a well-established radio frequency (RF) wireless indoor communication standard. Electromagnetic Pollution, relatively low data bandwidths, multipath interference of the indoor propagation to degrade performance, vulnerability to eavesdropping and susceptibility to security threats are major factors that favors LiFi in place of WiFi. However LiFi being an optical technology imposes great difficulty in implementing multiuser access in the Uplink from the user to router. Using Wavelength Division Multiplexing (WDM) for multiuser access drastically increases the cost and complexity of transceivers. This work presents a novel technique of multiuser access using Orthogonal Frequency Division Multiplexing (OFDM) with single carrier per user, implemented by envelope modulation of optical subcarriers for spatially separated users providing compatibility in uplink and downlink of LiFi standard based on OFDM.