LED to LED Multiple Input Single Output (MISO) Visible Light Communication (VLC) System

Abstract

This project had investigated the development and performance of a Multiple-Input Single-Output (MISO) Visible Light Communication (VLC) system using LED-to LED technology to facilitate unidirectional communication from multiple users to a single user. The transmitter side of the system had comprised two power LEDs, while the receiver side had featured a single power LED. The decision to employ a MISO system had been made due to its capability to achieve higher data rates and maintain good communication quality, even in the presence of interference and noise, compared to a conventional VLC system utilizing Single Input Single Output (SISO) architecture. The system had utilized two ESP32 WROOM microcontroller boards, programmed with Python, employing On-Off Keying (OOK) modulation to facilitate data transmission. The transmitter setup had included a 10W COB blue power LED and a 30W COB blue power LED, driven by 2N222 and D400 transistors, and managed by a 270-ohm resistor. On the receiver side, a 1W COB blue power LED had been used in conjunction with an LM358 operational amplifier (OPAMP) and a 1 Megaohm resistor to recover the transmitted signals. The results had indicated that the MISO LED-to-LED communication system had achieved significantly higher data rates and better communication quality than SISO systems, making it a promising approach for future wireless communication technologies. This research had contributed to the advancement of VLC systems by providing a detailed analysis of MISO configurations and their potential to overcome the limitations of traditional SISO architectures.