The College of Engineering Technologies – Al-Najaf at Al-Furat Al-Awsat Technical University witnessed the defense of a master’s thesis entitled:
“Design a Light Fidelity (Li-Fi) System Based on the Non-Orthogonal Multiple Access (NOMA) Scheme”
The study, presented by the researcher Zainab Hassan Mazhar from the Department of Communications Engineering Technologies, aimed to design an indoor optical wireless communication (Li-Fi) system based on the NOMA scheme to enhance spectral and energy efficiency and to support multiple users within indoor environments. The research adopted a Gain Ratio Power Allocation (GRPA) mechanism to ensure fairness among users, improve signal quality, and reduce interference. In addition, Adaptive Modulation and Coding (AMC) techniques were implemented using various modulation formats, including 16-QAM, 8-PSK, 4-QAM, and Continuous Phase Modulation (CPM), to increase data rates and reduce the bit error rate (BER).
A realistic indoor environment was modeled with dimensions of 10 × 6 × 3.5 m³, incorporating four distributed LED lamps. The study analyzed the impact of the optical channel under both line-of-sight (LOS) and non-line-of-sight (NLOS) conditions, as well as the influence of various noise sources.
The research focused on optimizing key performance metrics such as data rate, spectral efficiency, energy efficiency, latency, and bit error rate by integrating Li-Fi and NOMA technologies with adaptive power allocation and modulation techniques.
Simulation results conducted using MATLAB demonstrated that the proposed system achieved superior performance compared with conventional systems, attaining:
A data rate of approximately 150 Mbps.
Spectral efficiency of about 7 bits/s/Hz.
Low latency of approximately 1.4 ms.
A bit error rate lower than 10⁻¹⁰ at SNR = 20 dB, with a quality factor greater than 7.
The results also indicated a clear improvement in energy efficiency and communication reliability within multi-user indoor environments.
Overall, the findings confirm that the proposed system provides an effective solution for enhancing the performance of high-speed indoor optical wireless communication networks, particularly for sixth-generation (6G) applications and smart in-building internet systems.
