Article Per Year (5 Year)
p-Index From 2021 - 2026
0.408
P-Index
This Author published in this journals
All Journal Science, Technology, and Communication Journal
Precious, Oyibo Dafe
Unknown Affiliation
Computer Science & IT Electrical & Electronics Engineering Engineering Materials Science & Nanotechnology

Published : 2 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 2 Documents
Search

 1 
Simulation-based performance evaluation of reconfigurable intelligent surface (RIS)-assisted non-orthogonal multiple access (NOMA) networks Precious, Ikoko; Shaka, Samuel Oghenemega; Ogherohwo, Enoh Pius; Olisenekwu, Cletus; Precious, Oyibo Dafe
Science, Technology, and Communication Journal Vol. 6 No. 1 (2025): SINTECHCOM Journal (October 2025)
Publisher : Lembaga Studi Pendidikan dan Rekayasa Alam Riau

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.59190/stc.v6i1.326

Abstract

The integration of reconfigurable intelligent surfaces (RIS) into non-orthogonal multiple access (NOMA) networks presents a promising solution to the persistent interference and inefficiency challenges of modern wireless communication systems. This study investigates the impact of RIS on the performance of downlink NOMA networks using a simulation-based approach in MATLAB Simulink. The objective is to evaluate how RIS can enhance signal quality, reduce bit error rate (BER), improve spectral and energy efficiency, and minimize latency in densely connected environments. The methodology involves modeling a system with a base station, multiple users, and a RIS layer, analyzing various RIS configurations such as the number of reflecting elements and user distances ranging from 200 m to 1000 m. Results show that RIS-assisted NOMA significantly boosts signal-to-interference-plus-noise ratio (SINR) across all user pairs, achieving an average SINR gain of 6 dB e.g., SINR for users at 200 m improved from 12.5 dB to 18.7 dB. Similarly, BER dropped by up to 80%, spectral efficiency increased by 1 bps/Hz, and energy efficiency rose by 35%. Furthermore, outage probability reduced by more than 50%, and latency improved by approximately 3ms on average. These findings demonstrate the capacity of RIS to create a smart radio environment that overcomes path loss and interference bottlenecks, offering a scalable, energy-efficient, and low-latency solution for next-generation wireless networks.
Impact of differential group delay and environmental factors on signal quality in multimode fiber using NRZ and QAM modulation Precious, Oyibo Dafe; Shaka, Samuel Oghenemega; Ogherohwo, Enoh Pius; Olisenekwu, Cletus; Roseline, Agbosa Tobore; Agbajor, Godwin Kparobo
Science, Technology, and Communication Journal Vol. 6 No. 1 (2025): SINTECHCOM Journal (October 2025)
Publisher : Lembaga Studi Pendidikan dan Rekayasa Alam Riau

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.59190/stc.v6i1.327

Abstract

This study investigates the effects of polarization mode dispersion (PMD) on high-speed multimode fiber (MMF) optical communication systems, focusing on how differential group delay (DGD) and environmental conditions such as temperature and humidity influence signal quality. The research was conducted in Abuja, Nigeria, using two modulation formats—non-return-to-zero (NRZ) and quadrature amplitude modulation (QAM). Experimental measurements were carried out over fiber lengths ranging from 1 km to 38 km, and data rates from 15 Gbps to 240 Gbps. Key performance metrics such as bit error rate (BER), jitter, and signal-to-noise ratio (SNR) were analyzed in relation to DGD under varying environmental conditions. Results showed that DGD increased from 0.136 ps to 2.78 ps for NRZ and from 0.058 ps to 2.24 ps for QAM across the tested fiber lengths. Corresponding BER values for NRZ ranged from 1.18 × 10-7 to 1.35 × 10-7, while QAM showed slightly better performance with BER values between 1.18 × 10-7 and 1.29 × 10-7. Jitter rose from 4.26 ps to 31.20 ps in NRZ and from 4 ps to 33.54 ps in QAM. SNR values declined as DGD increased, with NRZ dropping from 34.59 dB to 54.56 dB and QAM from 34.83 dB to 52.90 dB. Environmental factors also played a role; temperature increases from 28.34°C to 29.90°C and humidity from 53.1% to 59.5% led to significant increases in DGD. The findings confirm that PMD, though less dominant in MMF than modal dispersion, still significantly affects signal quality in long-distance and high-speed MMF systems. QAM demonstrated greater resilience to PMD compared to NRZ. This study highlights the need for effective dispersion management and modulation format optimization in designing robust optical networks for environmentally dynamic regions like Abuja.
Co-Authors Agbajor, Godwin Kparobo Ogherohwo, Enoh Pius Olisenekwu, Cletus Precious, Ikoko Roseline, Agbosa Tobore Shaka, Samuel Oghenemega