Light-Fidelity Technology

Abstract

This research presents the design and development of a Li-Fi (Light Fidelity) based audio transmission system capable of transferring sound using visible light instead of traditional radio frequency (RF) communication. The model demonstrates how a modulated LED light source can transmit audio signals to a photodiode receiver, which reconstructs the original sound. The proposed system operates on the principle of intensity modulation and direct detection (IM/DD), allowing secure, interference-free, and short-range communication. The exper-imental setup uses low-cost electronic components, making it suitable for educational and laboratory demonstrations. Results confirm reliable transmission over a 3-meter range, high-lighting Li-Fi’s potential for future wireless communication technologies.

Introduction

The project focuses on Li-Fi (Light Fidelity) — a wireless communication technology that transmits data through visible light instead of traditional radio frequencies. Introduced by Prof. Harald Haas (2011), Li-Fi offers high-speed, secure, and interference-free communication by modulating LED light intensity to encode data. Unlike Wi-Fi, it avoids spectrum congestion and electromagnetic interference, making it ideal for sensitive environments like hospitals and aircraft.

The primary objective of this work is to design and demonstrate a Li-Fi Audio Transmission Model that enables real-time analog audio communication using light. The system comprises a transmitter (audio source, amplifier, and LED) and a receiver (photodiode, amplifier, and speaker). The LED’s brightness varies with the audio signal, and the photodiode converts the received light back into sound. The model showcases secure, short-range communication over a 2–3 meter range under line-of-sight (LOS) conditions.

The literature review outlines key aspects of Visible Light Communication (VLC), Li-Fi fundamentals, and modulation methods like OOK, PPM, and OFDM, with OFDM offering superior noise resistance. Studies confirm Li-Fi’s feasibility for audio transmission, low latency, and immunity to electromagnetic interference. Additionally, its physical-layer security ensures that light-based signals cannot penetrate walls, preventing data leakage.

The proposed system architecture operates on Intensity Modulation with Direct Detection (IM/DD) principles. Tests showed clear, low-distortion sound transmission up to 3 meters, with performance slightly affected by ambient light. The system’s cost-effectiveness (≈$6 total) and low power consumption make it ideal for educational use and prototype development.

However, the project faces limitations such as short communication range, ambient light interference, receiver sensitivity issues, and power inefficiency from continuous LED operation. Despite these challenges, the model successfully demonstrates Li-Fi’s potential for secure, real-time wireless communication, offering a foundation for future applications in IoT, 6G networks, and smart environments.

Conclusion

This research demonstrates that Li-Fi technology offers a feasible, low-cost, and efficient solution for short-range wireless audio transmission using visible light communication. The developed working model successfully transmits analog audio signals through variations in LED light intensity and reconstructs them using a photodiode receiver with minimal distortion. Experimental results confirm reliable performance within a 2–3 meter range under direct line-of-sight conditions, validating the system’s practical viability for educational and demonstrative purposes. The findings highlight that Li-Fi communication can over-come the limitations of conventional radio-frequency systems in environments where electromagnetic interference must be minimized. Its inherent security, energy efficiency, and high-speed potential make it a promising candidate for next-generation wireless systems. However, effective deployment on a larger scale requires advancements in LED modulation bandwidth, receiver sensitivity, and ambient light mitigation techniques Future work should focus on expanding Li-Fi applications beyond simple audio transmission toward high-speed digital data communication. Integration with Internet of Things (IoT) frameworks could enable smart indoor environments with simultaneous data and illumination functions. Multi-channel Li-Fi networks, adaptive beam alignment mechanisms, and hybrid Li-Fi/Wi-Fi architectures should be explored to enhance coverage and mobility. With continued research and interdisciplinary collaboration, Li-Fi technology has the potential to revolutionize short-range wireless communication and complement existing RF systems in smart infrastructure, healthcare, and educational sectors.

References

[1] K. Ahangama, H. P. Haripriya Premachandra, et al., “Enhanced Visible Light Communication for Real-Time Audio With Interference-Resilient Protocols,” IEEE Access, 2025. [2] [2] A. N., P. R. M., Impana B., Anusha Kumari, & S. Biradar, “Underwater Audio and Data Transmission System using Li-Fi Technology,” *Journal of Network Security & Computer Networks*, vol. 10, no. 1, pp. 1–10, 2024. [3] [3] P. Surya Kumar, P. Supraja, and I. Mamatha, “Secured Audio Com-munication Through Light,” in *Digital Communication and Soft Com-puting Approaches Towards Sustainable Energy Developments (ISSETA 2023)*, Springer, pp. 35-45, 2024. [4] [4] M. A. R. Eltokhy, M. Abdel-Hady, A. Haggag, et al., “Audio SIMO System Based on Visible Light Communication using Cavity LEDs,” *Multimedia Tools and Applications*, vol. 82, pp. 46371-46385, 2023. [5] [5] K. A. K. S. Surasinghe & Y. A. A. Kumarayapa, “Low Cost LED Source Based Transmission System for Achieving Free-Space Li-Fi Multimedia Communication,” *International Journal of Research & Scientific Innovation*, no. 1106051, 2024.

Copyright

Copyright © 2025 Shwet Gugale, Atharv Kadam, Gautam Kumar, Kashmira Nighlokar, Prof. Dayanand Aragde. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.