Serial Data Transmission using Visible Light Communication

Abstract

Li-Fi is a label for wireless-communication system using light as a carrier instead of radio frequencies as in Wi-Fi [1]. The light waves cannot penetrate walls hence Li-Fi (Light-Fidelity) can be used in sensitive areas such as in Aircraft [13, 15]. It can be implemented using white-LED light bulbs at the downlink transmitter. In these types of devices a constant current is applied for the purpose of illumination. However, by fast and subtle variations of the current, the optical output can be made to vary at extremely high speeds. Due to this characteristic of optical current it is used in Li-Fi setup. The operational procedure is very simple- if the LED is on, then transmit a 1, if it�s off then transmit a 0. The LEDs can be switched on and off very quickly, and hence it gives nice opportunities for transmitting data. All that is required is some LEDs and a controller that code data into those LEDs. All one has to do is to increase the rate at which the LED�s flicker [2] depending upon the data needs to be encode. Further enhancements can be made in this method, like we can use an array of LEDs for parallel data transmission, or using mixtures of red, green and blue LEDs. It can alter the light�s frequency with this approach each frequency encodes a different data Channel [5]. Such advancements promise a theoretical speed of 10 Gbps � meaning you can download a full high-definition film in just 30 seconds.