An Adaptive Finite Resolution Selection Scheme for RIS Assisted NOMA Networks

Non-orthogonal multiple access (NOMA) and reconfigurable intelligent surface (RIS) have recently been recognized as innovative technologies for future beyond fifth generation (B5G) wireless networks due to their ability to improve the spectral efficiency and the wireless propagation properties, resp...

Full description

Saved in:
Bibliographic Details
Main Authors: Shady M. Ibraheem, Mona Shokair, Mohamed E. Nasr, Nancy Alshaer
Format: Article
Language:English
Published: IEEE 2025-01-01
Series:IEEE Access
Subjects:
Online Access:https://ieeexplore.ieee.org/document/10849569/
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1832540537594314752
author Shady M. Ibraheem
Mona Shokair
Mohamed E. Nasr
Nancy Alshaer
author_facet Shady M. Ibraheem
Mona Shokair
Mohamed E. Nasr
Nancy Alshaer
author_sort Shady M. Ibraheem
collection DOAJ
description Non-orthogonal multiple access (NOMA) and reconfigurable intelligent surface (RIS) have recently been recognized as innovative technologies for future beyond fifth generation (B5G) wireless networks due to their ability to improve the spectral efficiency and the wireless propagation properties, respectively. This paper presents an integration between RIS and NOMA to communicate with distant vehicular users. To alleviate the complexity of coherent phase shifting design at RIS, we propose a dynamic gain adaptation RIS selection scheme based on discrete phase shifting (i.e., termed as GADPS) to serve two vehicular users paired to perform NOMA. Regarding channel state information (CSI), the adaptation mechanism determines which user can be considered as a near user and the other as a far user with respect to RIS. To characterize the benefits of the GADPS scheme, the system outage performance is derived and compared with the cases of random discrete phase shifting (i.e., termed as GARPS) and conventional RIS-NOMA schemes; then the diversity order is also obtained. Furthermore, the impact of network parameters on the throughput and asymptotic average sum rate is discussed in both delay-limited and delay-tolerant transmission modes, respectively. Monte Carlo simulations emphasize the accuracy of the analytical work and investigate that: 1) The proposed GADPS scheme is more flexible than conventional RIS-NOMA scheme; 2) By joint optimization of RIS selection and phase shifting, the proposed GADPS scheme is capable of achieving superior performance over GARPS and conventional RIS-NOMA schemes with a superior diversity gain; 3) The throughput performance of the proposed GADPS scheme outperforms GARPS, conventional RIS-NOMA and other relay-assisted NOMA schemes, whereas full-duplex (FD) relay selection NOMA schemes suffer from throughput floor values; 4) By increasing the number of reflecting elements of RIS, the proposed GADPS scheme achieves the enhanced average sum rate performance over benchmark schemes in all scenarios of relative distance difference between users and the selected RIS.
format Article
id doaj-art-7a0a314133374da48d430e84e31ce083
institution Kabale University
issn 2169-3536
language English
publishDate 2025-01-01
publisher IEEE
record_format Article
series IEEE Access
spelling doaj-art-7a0a314133374da48d430e84e31ce0832025-02-05T00:01:12ZengIEEEIEEE Access2169-35362025-01-0113209742098810.1109/ACCESS.2025.353285210849569An Adaptive Finite Resolution Selection Scheme for RIS Assisted NOMA NetworksShady M. Ibraheem0https://orcid.org/0000-0002-0506-0024Mona Shokair1Mohamed E. Nasr2Nancy Alshaer3https://orcid.org/0000-0002-2678-7273Electronics and Electrical Communications Department, Faculty of Engineering, Tanta University, Tanta, EgyptElectronics and Electrical Communications Department, Faculty of Electronic Engineering, Menoufia University, Shebeen El-Kom, EgyptElectronics and Electrical Communications Department, Faculty of Engineering, Tanta University, Tanta, EgyptElectronics and Electrical Communications Department, Faculty of Engineering, Tanta University, Tanta, EgyptNon-orthogonal multiple access (NOMA) and reconfigurable intelligent surface (RIS) have recently been recognized as innovative technologies for future beyond fifth generation (B5G) wireless networks due to their ability to improve the spectral efficiency and the wireless propagation properties, respectively. This paper presents an integration between RIS and NOMA to communicate with distant vehicular users. To alleviate the complexity of coherent phase shifting design at RIS, we propose a dynamic gain adaptation RIS selection scheme based on discrete phase shifting (i.e., termed as GADPS) to serve two vehicular users paired to perform NOMA. Regarding channel state information (CSI), the adaptation mechanism determines which user can be considered as a near user and the other as a far user with respect to RIS. To characterize the benefits of the GADPS scheme, the system outage performance is derived and compared with the cases of random discrete phase shifting (i.e., termed as GARPS) and conventional RIS-NOMA schemes; then the diversity order is also obtained. Furthermore, the impact of network parameters on the throughput and asymptotic average sum rate is discussed in both delay-limited and delay-tolerant transmission modes, respectively. Monte Carlo simulations emphasize the accuracy of the analytical work and investigate that: 1) The proposed GADPS scheme is more flexible than conventional RIS-NOMA scheme; 2) By joint optimization of RIS selection and phase shifting, the proposed GADPS scheme is capable of achieving superior performance over GARPS and conventional RIS-NOMA schemes with a superior diversity gain; 3) The throughput performance of the proposed GADPS scheme outperforms GARPS, conventional RIS-NOMA and other relay-assisted NOMA schemes, whereas full-duplex (FD) relay selection NOMA schemes suffer from throughput floor values; 4) By increasing the number of reflecting elements of RIS, the proposed GADPS scheme achieves the enhanced average sum rate performance over benchmark schemes in all scenarios of relative distance difference between users and the selected RIS.https://ieeexplore.ieee.org/document/10849569/Non-orthogonal multiple accessreconfigurable intelligent surfaceoutage probabilitydiscrete phase shifting
spellingShingle Shady M. Ibraheem
Mona Shokair
Mohamed E. Nasr
Nancy Alshaer
An Adaptive Finite Resolution Selection Scheme for RIS Assisted NOMA Networks
IEEE Access
Non-orthogonal multiple access
reconfigurable intelligent surface
outage probability
discrete phase shifting
title An Adaptive Finite Resolution Selection Scheme for RIS Assisted NOMA Networks
title_full An Adaptive Finite Resolution Selection Scheme for RIS Assisted NOMA Networks
title_fullStr An Adaptive Finite Resolution Selection Scheme for RIS Assisted NOMA Networks
title_full_unstemmed An Adaptive Finite Resolution Selection Scheme for RIS Assisted NOMA Networks
title_short An Adaptive Finite Resolution Selection Scheme for RIS Assisted NOMA Networks
title_sort adaptive finite resolution selection scheme for ris assisted noma networks
topic Non-orthogonal multiple access
reconfigurable intelligent surface
outage probability
discrete phase shifting
url https://ieeexplore.ieee.org/document/10849569/
work_keys_str_mv AT shadymibraheem anadaptivefiniteresolutionselectionschemeforrisassistednomanetworks
AT monashokair anadaptivefiniteresolutionselectionschemeforrisassistednomanetworks
AT mohamedenasr anadaptivefiniteresolutionselectionschemeforrisassistednomanetworks
AT nancyalshaer anadaptivefiniteresolutionselectionschemeforrisassistednomanetworks
AT shadymibraheem adaptivefiniteresolutionselectionschemeforrisassistednomanetworks
AT monashokair adaptivefiniteresolutionselectionschemeforrisassistednomanetworks
AT mohamedenasr adaptivefiniteresolutionselectionschemeforrisassistednomanetworks
AT nancyalshaer adaptivefiniteresolutionselectionschemeforrisassistednomanetworks