Results 51 to 60 of about 2,701 (178)

Impact of clipping noise on the sum rate of NOMA with PD-DCO-OFDM and conventional DCO-OFDM

Heliyon, 2020
sIn visible light communication (VLC) systems, a non-orthogonal multiple access (NOMA) scheme is deemed promising technology to offer better spectral efficiency than the Orthogonal multiple access (OMA) scheme.
Zelalem Hailu Gebeyehu
doaj   +1 more source

Non-Orthogonal Multiple Access (NOMA): How It Meets 5G and Beyond

CoRR, 2019
Due to massive connectivity and increasing demands of various services and data-hungry applications, a full-scale implementation of the fifth generation (5G) wireless systems requires more effective radio access techniques. In this regard, non-orthogonal multiple access (NOMA) has recently gained ever-growing attention from both academia and industry ...
S. M. Riazul Islam, Ming Zeng 0002, Octavia A. Dobre, Kyung Sup Kwak   +3 more
openaire   +2 more sources

Time and phase alignment of distributed gateways: Theoretical analysis and experimental demonstration

International Journal of Satellite Communications and Networking, Volume 44, Issue 1, Page 47-59, January/February 2026.
The performance limitation in multiple‐input multiple‐output (MIMO) feeder links due to time and phase misalignment of the ground stations is investigated. Time and phase distribution over optical fiber is considered as an approach to achieve the synchronization requirements.
Eriserdi Mollaymeri, Thomas Delamotte, Andreas Knopp   +2 more
wiley   +1 more source

Cell-Free Massive MIMO System With an Adaptive Switching Algorithm Between Cooperative NOMA, Non-Cooperative NOMA, and OMA Modes

IEEE Access, 2021
Non-orthogonal multiple access (NOMA) aided cell-free massive multiple-input multiple-output (CF mMIMO) systems have gained great attention over the past few years to be employed in the sixth generation of the wireless network.
Reza Sayyari, Jafar Pourrostam, Mir Javad Musevi Niya   +2 more
doaj   +1 more source

Spatial distribution of 6s2 lone electron pair in Pb4Na(PO4)3 and stereochemical activity of the 6s2 electron cloud in lead‐bearing apatites

Acta Crystallographica Section B, Volume 82, Issue 1, Page 68-77, February 2026.
In lacunary apatite structure‐type Pb4Na(PO4)3, residual density attributable to the deformed 6s2 electron cloud is found in the vicinity of A2‐site Pb2+ on regular A2 triangle normal to c. Systematic comparison on the size of the A2 triangle with other apatite‐type compounds indicates limited stereochemical activity of the orbital.Single crystals of ...
Kotomi Hirano, Hiroki Okudera
wiley   +1 more source

Robust Spectral and Energy Efficiency Tradeoff for RIS‐Aided Multi‐User Communication

IET Communications, Volume 20, Issue 1, January/December 2026.
In this work, an RIS‐aided multi‐user network with imperfect CSI is investigated. Correspondingly, we focus on balancing SE and EE through the collaborative design of the base station (BS)'s precoding matrix and the RIS's phase shifts, which consider the transmit power budget and the channel uncertainties constraints.
Xiandeng He, Yilin Wang, Shun Zhang
wiley   +1 more source

A Systematic Review on Non-Orthogonal Multiple Access (NOMA) Based on Visible Light Communication for Intelligent Transportation Systems

Tikrit Journal of Engineering Sciences
Non-Orthogonal Multiple Access (NOMA) is a cutting-edge technology that permits several users to use the same frequency resources and transfer data at once. Visible light communication also known as VLC, is an innovative technology that offers access to
Seba Adnan Yosef, Lwaa Faisal Abdulameer
doaj   +1 more source

A Massive Grant‐Free Random Access Scheme Based on Spectrum Sensing and Preamble Delay

IET Communications, Volume 20, Issue 1, January/December 2026.
This paper introduces cognitive radio (CR) and preamble delay (PD) to reduce access collisions, together with non‐orthogonal multiple access (NOMA) to improve spectrum efficiency, and thus proposes an efficient CR‐NOMA‐PD‐based massive grant‐free random multiple access scheme.
Jing Zhang, Zhuang‐Zhuang Wei, Yu‐Qi Zhang, Hong‐Xu Gao, Hai‐Tao Zhao, Hong‐Bo Zhu   +5 more
wiley   +1 more source

Joint Optimization Algorithm for UAV Trajectory and Beamforming for NOMA‐Based Integrated Sensing and Communication (ISAC) Systems

IET Communications, Volume 20, Issue 1, January/December 2026.
This paper investgates a unmanned aerial vehicle‐assisted non‐orthogonal multiple access‐integrated sensing and communication system, which fuses the UAV's echo signal and target position by employing the extended Kalman filter algorithum to achieve high‐precision prediction of the target trajectory.
Dongsheng Han, Zian Wang, Yan Wang
wiley   +1 more source

Joint Decision‐Making for UAV Deployment and Computational Offloading Optimized for Energy Consumption and Latency in Space‐Air‐Ground Integrated Networks

IET Communications, Volume 20, Issue 1, January/December 2026.
Within the framework of integrated space‐air‐ground edge computing networks, this paper investigates the joint optimization of task allocation, user‐UAV association, UAV deployment, and computation resource allocation between UAVs and the LEO satellite.
Tengda Huang, Tao Hu, Di Wu, Wenzhi Zhao
wiley   +1 more source