Page 61 - IJEEE-2023-Vol19-ISSUE-1

Received: 29 August 2022 Revised: 12 September 2022 Accepted: 12 September 2022
DOI: 10.37917/ijeee.19.1.7
Vol. 19| Issue 1| June 2023

Ð Open Access

Iraqi Journal for Electrical and Electronic Engineering

Original Article

Enhancement Spectral and Energy Efficiencies for
Cooperative NOMA Networks

Haider S. Msayer*1,2, Husham L. Swadi1, Haider M. AlSabbagh1
1 Department of Electrical Engineering, College of Engineering, University of Basrah, Basrah, Iraq.

2 Basra Oil Company (BOC), Basrah, Iraq.

Correspondence
*Haider Shaker Msayer
Department of Electrical Engineering,
College of Engineering, University of Basrah,
Basrah, Iraq.
Email: haidermsc2020@gmail.com

Abstract
The tremendous development in the field of communications is derived from the increasing demand for fast transmission

and processing of huge amounts of data. The non-orthogonal multiple access (NOMA) system was proposed to increase spectral
efficiency (SE) and improve energy efficiency (EE) as well as contribute to preserving the environment and reducing pollution.
In the NOMA system, a user may be considered as a relay to the others that support the coverage area based on adopting the
reuse of the frequency technique. This cooperation enhances the spectral efficiency, however, in the cell, there are other users
that may affect the spectral allocation that should be taken into consideration. Therefore, this paper is conducted to analyze the
case when three users are available to play as relies upon. The analyses are performed in terms of the transmitted power
allocation in a fair manner, and the system's performance is analyzed using the achievable data rates and the probability of an
outage. The results showed an improvement in throughputs for the second and third users, as its value ranged from 7.57 bps/Hz
to 12.55 bps/Hz for the second user and a quasi-fixed value of 1,292 bps/Hz for the third user at the transmitted power ranging
from zero to 30 dBm.
KEYWORDS: Energy Efficiency, Spectral Efficiency, Cooperative Non-Orthogonal Multiple Access, Relay.

I. INTRODUCTION as energy increase leads to serious creates significant
environmental, economic and financial risks to the world [5].
The mature 4G networks were successfully applied in The increased energy consumption, the rise greenhouse gas
different types of wireless communications to satisfy the emissions, the large carbon footprint, the increased health
increasing demand for cellular data traffic that have high concerns on humans and the environment and the strive to
capacities and speed. However, the demand was ambitious to extend the battery lifetime of smart devices. All these
enhance connecting ALL things through the internet that challenges lead to the term green communication (GC) [6].
required a considerable attention to allocate the available
limited spectral [1]. The quest to make the 5G and beyond to improve energy
efficiency and to increase sources of clean energy, preserve
Researchers turned to 5G with some new protocols to the environment from high carbon, preserve primary energy
support high speed and a large capacity that need a very high sources from overuse and search for alternative sources that
bandwidth to enhance the spectrum efficiency [2,3]. The reduce pollution in the world, as well as reduce operational
trend towards 5G meets many requirements of the expenses that burden the field of communications financially
tremendous technological development that is increasing and economically [7].
exponentially, it provides capacities 1000 times more than
4G with a large bandwidth and very high speeds of up to 10 5G networks operate with higher bandwidth than previous
Gigabits per second. This unprecedented technological generations, this allows them to have a high download speed
progress requires the provision of Infrastructures that of up to 10 G /sec and with the increase in bandwidth that
accommodate the massive increase of devices served by 5G will serve cellular networks. In addition to being used as an
networks [1,4]. Internet service provider in general for all mobile and
desktop devices and to support new applications in the
Transformation to 5G requires a rise in energy Internet-of-Things (IoT) and machine-to-machine domains
consumption, a significant increase in energy bills, and an [8,9].
increase in the operating costs of the mobile phone network,

This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and

reproduction in any medium, provided the original work is properly cited.

© 2023 The Authors. Published by Iraqi Journal for Electrical and Electronic Engineering by College of Engineering, University of Basrah.

https://doi.org/10.37917/ijeee.19.1.7 https://www.ijeee.edu.iq 57