Low Cost Light Fidelity (Li-Fi) System Employing On-Off Keying Data Modulation in Half-Duplex Asynchronous Transmission Mode

Abstract

In recent years, Light Fidelity (LiFi) technology has gained more and more attention due to its ability to transmit large data in a short time, and prevents interference and radiation compared to conventional WiFi communication. Therefore, it is more preferable to be employed in health care related sector. In this paper, a low cost wireless data communication using Li-Fi Technology is presented. This project employed On-Off Keying (OOK) Modulation Technique to encode and decode messages. A pair of prototype transceivers were developed and adapting Half-Duplex Asynchronous Transmission Mode. The overall hardware is employing Arduino Nano and LEDs and hence the price was kept around USD 25. The entire system was being tested on four different aspects and they were data transmission duration, distance between transceivers, the transmission angle of the transceivers and the message capacity. These tests were being evaluated by Word Error Rate (WER) to acquire the accuracy. In short, the transceivers were able to transmit and receive all the alphabets, numbers and symbols on the ASCII computer keyboard. It works optimally with the transceiver angle of ±10° in a distance of 20cm with the minimum delay of 102ms. The data modulation techniques and the hardware selection were believed as the factors to improve the system performance.