Results 71 to 80 of about 26,640 (235)

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

Progressive Pattern Interleaver with Multi-Carrier Modulation Schemes and Iterative Multi-User Detection in IoT 6G Environments with Multipath Channels

Sensors
Sixth-generation (6G) wireless networks demand a more efficient implementation of non-orthogonal multiple access (NOMA) schemes for severe multipath fading environments to serve multiple users.
Shivani Dixit, Varun Shukla, Manoj Kumar Misra, Jose M. Jimenez, Jaime Lloret   +4 more
doaj   +1 more source

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

Is NOMA Efficient in Multi-Antenna Networks? A Critical Look at Next Generation Multiple Access Techniques

IEEE Open Journal of the Communications Society, 2021
In the past few years, a large body of literature has been created on downlink Non-Orthogonal Multiple Access (NOMA), employing superposition coding and Successive Interference Cancellation (SIC), in multi-antenna wireless networks.
Bruno Clerckx, Yijie Mao, Robert Schober, Eduard A. Jorswieck, David J. Love, Jinhong Yuan, Lajos Hanzo, Geoffrey Ye Li, Erik G. Larsson, Giuseppe Caire   +9 more
doaj   +1 more source

Fairness Comparison of Uplink NOMA and OMA

, 2017
In this paper, we compare the resource allocation fairness of uplink communications between non-orthogonal multiple access (NOMA) schemes and orthogonal multiple access (OMA) schemes.
Guo, Jiajia, Ng, Derrick Wing Kwan, Wei, Zhiqiang, Yuan, Jinhong   +3 more
core   +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

D2D user and cellular user communication scheme based on NOMA

Dianzi Jishu Yingyong, 2023
LTE network adopts non orthogonal multiple access to enhance network capacity and D2D to improve spectral efficiency. Allowing D2D users to share the spectrum resources of cellular users using non orthogonal multiple access technology can alleviate the ...
Zhu Liyuan, Wang Bin, Wang Wennai
doaj   +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

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