Enabling 5G wireless access using Li-Fi technology: An OFDM based approach

The 5G wireless mobile networking technology is being investigated by the research community to enhance the performances of mobility service by increasing the data rates provided to users and reducing transmission delays. One alternative to achieve these objectives is to use different accessing techniques in outdoor and indoor environments. The light fidelity (LiFi) technology is one of the promising solutions to increase transmission capacity in the indoor scenario. It is based on light emitting diodes (LEDs) to enable high speed communication with a fully networking capabilities. One issue in implementing LiFi is to select the appropriate access technique in the multiuser environment. In this paper, we investigate orthogonal frequency division multiplexing (OFDM) to reach targets using 5G optical wireless access in terms of data rates and transmission delays. Specifically, we propose a LiFi access-point architecture that implements a novel OFDM encoding/decoding technique based on delaying optical pulses in a vector of optical delay lines loops (ODLs). An optical switch will determine the subcarriers frequencies that must be selected to generate the user specific OFDM code. The encoding/decoding architecture is fully reconfigurable by dynamically modifying the number of rounds that must be performed by the optical pulse in the ODL and the wavelengths that must be selected by the optical switch. The design and the performance study of our dynamic OFDM all-optical encoding/decoding technique is performed to show that it can achieve the requirements of the 5G access technology.