رسائل ماجيستير
English
2018
Design of Light Fidelity System using Red Green and Blue Light Emitting Diode
Suleiman Abdalrahman Abdalla , Jiwayria Mohammed Saeed Dawlbeit Babiker, Mortuda Mohammed Abdalwhab
كلية الهندسة والتكنولوجيا-جامعة الجزيرة · السودان
Wireless communications, play an important role in our life (mobile communication, Bluetooth, Wireless Fidelity (Wi-Fi), etc.) as radio spectrum is almost been used , for this reason a different technology, Light Fidelity (Li-Fi) has been used to change the face of communication world using a part of electromagnetic spectrum which is visible light spectrum. Li-Fi technology is based on visible light communication (VLC) technology which delivers bidirectional, high-speed, networked mobile communications by using light from light-emitting diodes (LEDs). The objective of this research is to design a Li- Fi system using parallel transmission mode based on red, green, blue LED (RGB LED) as a source of light to provide an optimum usage for bandwidth. In this research a Li-Fi circuit was designed by Proteus isis7 software simulation program .The design consists of transmitter and receiver which can transfer textual and audio data. The RGB LED generate seven colors light which controlled by Arduino Uno microcontroller. Each color light has different wavelength and different frequency which allows the transmission of different data at the same time on the single LED. In the transmitter site the data are processed in suitable form to feed the RGB LED through the Arduino Uno microcontroller which modulates the input data with light pulses and also controlling the RGB LED. If the LED is “on” then a digital one is transmitted and if the LED is “off” then a digital zero is transmitted, the modulation is so fast that human eye doesn’t notice. The modulated signal propagated on the free space channel. In the receiver the light dependent resistor (LDR) was used as a photo detector to receive the light pulses and demodulate data from light based on the incoming sequences of 1’s and 0’s , the demodulated signal was processed and filtered to remove unwanted noise and to recover the original data. The design was tested by transmitting text and audio, the received data (text and audio) were completely correct, the obtained text displayed on the liquid crystal display (LCD) screen and the audio heard by the listener on the speaker device. This work recommends utilizing the other wavelengths that are available on the RGB LED colors light to transfer other types of data and use encoder / decoder to prevent the transmitted data from being lost and reduce error.