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11,249 Results Found

  • Article
  • Open Access
9 Citations
4,866 Views
20 Pages

User-Centric Cell-Free Massive MIMO with Low-Resolution ADCs for Massive Access

  • Jin-Woo Kim,
  • Hyoung-Do Kim,
  • Kyung-Ho Shin,
  • Sang-Wook Park and ,
  • Seung-Hwan Seo,
  • Yoon-Ju Choi,
  • Young-Hwan You and
  • Hyoung-Kyu Song
  • + 3 authors+ 0 author

6 August 2024

This paper proposes a heuristic association algorithm between access points (APs) and user equipment (UE) in user-centric cell-free massive multiple-input-multiple-output (MIMO) systems, specifically targeting scenarios where UEs share the same frequ...

(This article belongs to the Section Sensor Networks)
  • Article
  • Open Access
2 Citations
2,099 Views
14 Pages

2 June 2023

Cell-free massive multiple-input multiple-output (MIMO) is a promising technology for the Internet of Things (IoT) because it can increase connectivity and provide considerable energy efficiency (EE) and spectral efficiency (SE). However, pilot conta...

(This article belongs to the Special Issue 6G Wireless Communication and Its Applications)
  • Feature Paper
  • Review
  • Open Access
105 Citations
22,178 Views
29 Pages

Massive MIMO Wireless Networks: An Overview

  • Noha Hassan and
  • Xavier Fernando

Massive multiple-input-multiple-output (MIMO) systems use few hundred antennas to simultaneously serve large number of wireless broadband terminals. It has been incorporated into standards like long term evolution (LTE) and IEEE802.11 (Wi-Fi). Basica...

(This article belongs to the Special Issue Smart Antennas and MIMO Communications)
  • Article
  • Open Access
13 Citations
5,456 Views
21 Pages

LDPC Coded Massive MIMO Systems

  • Inho Hwang,
  • Han Jin Park and
  • Jeong Woo Lee

27 February 2019

We design a coded massive multiple-input multiple-output (MIMO) system using low-density parity-check (LDPC) codes and iterative joint detection and decoding (JDD) algorithm employing a low complexity detection. We introduce the factor graph represen...

(This article belongs to the Section Information Theory, Probability and Statistics)
  • Article
  • Open Access
6 Citations
1,884 Views
18 Pages

Massive Graviton from Diffeomorphism Invariance

  • João M. L. de Freitas and
  • Iberê Kuntz

In this work, we undertake a comprehensive study of the functional measure of gravitational path integrals within a general framework involving non-trivial configuration spaces. As in Riemannian geometry, the integration over non-trival configuration...

(This article belongs to the Section Gravitation)
  • Perspective
  • Open Access
98 Citations
14,793 Views
22 Pages

Technology Trends for Massive MIMO towards 6G

  • Yiming Huo,
  • Xingqin Lin,
  • Boya Di,
  • Hongliang Zhang and ,
  • Francisco Javier Lorca Hernando,
  • Ahmet Serdar Tan,
  • Shahid Mumtaz,
  • Özlem Tuğfe Demir and
  • Kun Chen-Hu
  • + 4 authors+ 0 author

30 June 2023

At the dawn of the next-generation wireless systems and networks, massive multiple-input multiple-output (MIMO) in combination with leading-edge technologies, methodologies, and architectures are poised to be a cornerstone technology. Capitalizing on...

(This article belongs to the Section Communications)
  • Review
  • Open Access
92 Citations
19,504 Views
29 Pages

Massive MIMO Techniques for 5G and Beyond—Opportunities and Challenges

  • David Borges,
  • Paulo Montezuma,
  • Rui Dinis and
  • Marko Beko

Telecommunications have grown to be a pillar to a functional society and the urge for reliable and high throughput systems has become the main objective of researchers and engineers. State-of-the-art work considers massive Multiple-Input Multiple-Out...

(This article belongs to the Special Issue 10th Anniversary of Electronics: Advances in Microwave and Wireless Communications)
  • Review
  • Open Access
23 Citations
11,948 Views
7 Pages

Massive Open Online Courses

  • Tharindu Rekha Liyanagunawardena

28 January 2015

Massive Open Online Courses (MOOCs) are a new addition to the open educational provision. They are offered mainly by prestigious universities on various commercial and non-commercial MOOC platforms allowing anyone who is interested to experience the...

(This article belongs to the Collection Idea of the University)
  • Article
  • Open Access
3 Citations
3,104 Views
20 Pages

10 October 2020

In this paper, the scaling laws of scheduling gain and the feasibility of user scheduling for uplink massive multiple input–multiple output (MIMO) systems are investigated by analyzing the second moment of mutual information. We consider two we...

(This article belongs to the Special Issue Enabling-5G)
  • Article
  • Open Access
1 Citations
1,422 Views
11 Pages

A Novel Performance Bound for Massive MIMO Enabled HetNets

  • Hao Li,
  • Jiawei Cao,
  • Guangkun Luo,
  • Zhigang Wang and
  • Houjun Wang

25 June 2023

Massive multiple-input and multiple-output (MIMO) networks with higher throughput rates, where a base station (BS) with a large-scale antenna array serves multiple users, have been widely employed in next-generation wireless communication test system...

(This article belongs to the Special Issue Advances in Mobile Network and Intelligent Communication)
  • Feature Paper
  • Review
  • Open Access
25 Citations
10,416 Views
29 Pages

12 August 2020

We present a review of UV observations of massive stars and their analysis. We discuss O stars, luminous blue variables, and Wolf–Rayet stars. Because of their effective temperature, the UV (912−3200 Å) provides invaluable diagnosti...

(This article belongs to the Special Issue Star Formation in the Ultraviolet)
  • Article
  • Open Access
1 Citations
1,520 Views
17 Pages

2 September 2025

With the advancement of mobile communications, technologies based on high-element-count antenna systems—such as massive Multiple Input Multiple Output (massive MIMO)—are playing an increasingly important role in enhancing network capacity...

  • Review
  • Open Access
1 Citations
2,271 Views
13 Pages

1 October 2022

Since the Cosmic Dawn, massive stars have been playing a crucial role as the chemical recycling engines of galaxies that enable the birth of new stars and planetary systems, not only through the strong winds that they exhibit during their relatively...

(This article belongs to the Section Solar and Stellar Physics)
  • Review
  • Open Access
19 Citations
3,852 Views
24 Pages

11 October 2023

In this paper, we review our current understanding of the outer envelope structures of massive stars based on three-dimensional (3D) radiation hydrodynamic simulations. We briefly summarize the fundamental issues in constructing hydrostatic one-dimen...

(This article belongs to the Special Issue The Structure and Evolution of Stars)
  • Article
  • Open Access
5 Citations
2,134 Views
18 Pages

6 July 2023

Massive MIMO systems can support a large number of Internet of Things (IoT) devices, even if the number of IoT devices exceeds the number of service antennas in a single base station (BS) located at the data center. In order to improve the performanc...

(This article belongs to the Section E2: Control Theory and Mechanics)
  • Article
  • Open Access
15 Citations
4,020 Views
14 Pages

7 February 2018

We apply the Bogoliubov transformations in order to connect two different vacuums, one located at past infinity and another located at future infinity around a black hole inside the scenario of the nonlinear theory of massive gravity. The presence of...

(This article belongs to the Special Issue Black Hole Thermodynamics)
  • Article
  • Open Access
5 Citations
3,377 Views
14 Pages

Efficient User-Serving Scheme in the User-Centric Cell-Free Massive MIMO System

  • Ji-Hye Oh,
  • Beom-Sik Shin,
  • Min-A Kim,
  • Young-Hwan You and ,
  • Duck-Dong Hwang and
  • Hyoung-Kyu Song
  • + 1 author+ 0 author

17 May 2022

A cell-free massive multiple input multiple output (MIMO) system is an attractive network model that is in the spotlight in 5G and future communication systems. Despite numerous advantages, the cell-free massive MIMO system has a problem in that it i...

(This article belongs to the Section Communications)
  • Article
  • Open Access
58 Citations
11,492 Views
13 Pages

Hybrid Beamforming in Massive MIMO for Next-Generation Communication Technology

  • Shahid Hamid,
  • Shakti Raj Chopra,
  • Akhil Gupta,
  • Sudeep Tanwar and ,
  • Bogdan Cristian Florea,
  • Dragos Daniel Taralunga,
  • Osama Alfarraj and
  • Ahmed M. Shehata
  • + 3 authors+ 0 author

21 August 2023

Hybrid beamforming is a viable method for lowering the complexity and expense of massive multiple-input multiple-output systems while achieving high data rates on track with digital beamforming. To this end, the purpose of the research reported in th...

(This article belongs to the Section Communications)
  • Article
  • Open Access
7 Citations
5,526 Views
14 Pages

An Improved Jacobi-Based Detector for Massive MIMO Systems

  • Xiaoqing Zhao,
  • Zhengquan Li,
  • Song Xing,
  • Yang Liu and ,
  • Qiong Wu and
  • Baolong Li
  • + 1 author+ 0 author

Massive multiple-input-multiple-output (MIMO) is one of the key technologies in the fifth generation (5G) cellular communication systems. For uplink massive MIMO systems, the typical linear detection such as minimum mean square error (MMSE) presents...

(This article belongs to the Section Information and Communications Technology)
  • Communication
  • Open Access
2,589 Views
11 Pages

14 January 2024

Massive MIMO networks are a promising technology for achieving ultra-high capacity and meeting future wireless service demand. Massive MIMO networks, on the other hand, consume intensive energy. As a result, energy-efficient operation of massive MMO...

(This article belongs to the Special Issue MIMO Technologies in Sensors and Wireless Communication Applications)
  • Article
  • Open Access
13 Citations
4,025 Views
17 Pages

Massive multiple-input multiple-output (MIMO) is a profitable technique to greatly boost spectral efficiency, which has been embraced by the fifth-generation (5G) and sixth-generation (6G) mobile communication systems. By exploiting appropriate downl...

(This article belongs to the Special Issue MIMO System Technology for Wireless Communications)
  • Article
  • Open Access
13 Citations
5,375 Views
14 Pages

Microstructure Characterization of Massive Ferrite in Laser-Weldments of Interstitial-Free Steels

  • Benjamin Pei-Herng Liu,
  • Tsai-Fu Chung,
  • Jer-Ren Yang,
  • Jianxun Fu and ,
  • Chih-Yuan Chen,
  • Shing-Hoa Wang,
  • Ming-Chin Tsai and
  • Ching-Yuan Huang
  • + 3 authors+ 0 author

5 July 2020

Laser welding, which is known for its precision and high welding rate, offers a high-cooling-rate processing environment. In this study, laser welding was applied to interstitial-free steel plates with phosphorous additions of 0.002 and 0.009 wt%. Af...

  • Article
  • Open Access
6 Citations
3,697 Views
11 Pages

28 December 2021

We run a numerical experiment ejecting stellar winds in a very massive binary system measuring the properties of the resulting colliding wind structure and accreted mass onto the companion under different conditions. Colliding massive binaries intera...

(This article belongs to the Special Issue Asymmetric Planetary Nebulae 8e)
  • Article
  • Open Access
23 Citations
4,142 Views
15 Pages

Power-Ordered NOMA with Massive MIMO for 5G Systems

  • Mário Marques da Silva and
  • Rui Dinis

15 April 2021

The aim of this article is to study the conventional and cooperative power-order Non-Orthogonal Multiple Access (NOMA) using the Single Carrier with Frequency Domain Equalization (SC-FDE) block transmission technique, associated with massive Multiple...

(This article belongs to the Special Issue Massive MIMO Systems for 5G and beyond Networks: Latest Advances and Prospects)
  • Case Report
  • Open Access
1 Citations
1 Views
2 Pages

A Rare Massive Exophytic Gingival Growth

  • Suvy Manuel,
  • Surej L.K. Kumar and
  • Bindu J. Nair

Oral surgeons ought to be aware of variety of lesions that can present as focal exophytic gingival overgrowths. Most gingival lesions arise due to local irritating factors. The case presented share dramatic clinical pictures and findings of a long-st...

  • Tutorial
  • Open Access
33 Citations
9,469 Views
21 Pages

4 January 2019

Massive multiple input multiple output (MIMO) technology is one of the promising technologies for fifth generation (5G) cellular communications. In this technology, each cell has a base station (BS) with a large number of antennas, allowing the simul...

(This article belongs to the Section Sensor Networks)
  • Article
  • Open Access
4 Citations
4,520 Views
11 Pages

13 September 2018

Massive multiple-input multiple-output (MIMO) has been viewed as an advanced technique in future 5G networks. Conventional massive MIMO systems consist of cellular base stations (BS) equipped with a very large number of antennas to simultaneously ser...

(This article belongs to the Special Issue Green Communications in Smart City)
  • Article
  • Open Access
1 Citations
2,688 Views
13 Pages

16 March 2022

The vacuum radiation of a massive scalar field is studied by means of a single moving mirror. The field equation with an arbitrary-shaped mirror moving in (d+1) dimensions is given perturbatively in the non-relativistic limit. Explicit results are ob...

(This article belongs to the Section Field Theory)
  • Article
  • Open Access
5 Citations
3,212 Views
17 Pages

Precoder Design for Network Massive MIMO Optical Wireless Communications

  • Zakir Ali,
  • Chen Sun,
  • Qasim Jan,
  • Muhammad Furqan and
  • Xiqi Gao

11 August 2024

Precoding is a technique employed to enhance transmission rates in various communication systems, including massive multiple-input multiple-output (MIMO) and optical wireless communication (OWC). In this study, we focus on network massive MIMO OWC (N...

(This article belongs to the Section Communications)
  • Article
  • Open Access
10 Citations
3,457 Views
20 Pages

2 November 2020

In this paper, we propose a novel statistical beamforming (SBF) method called the partial-nulling-based SBF (PN-SBF) to serve a number of users that are undergoing distinct degrees of spatial channel correlations in massive multiple-input multiple-ou...

(This article belongs to the Special Issue Advanced Physical-Layer Technologies for beyond 5G Wireless Communication Networks)
  • Article
  • Open Access
4 Citations
2,139 Views
31 Pages

The Strongly Asynchronous Massive Access Channel

  • Sara Shahi,
  • Daniela Tuninetti and
  • Natasha Devroye

29 December 2022

This paper considers the Strongly Asynchronous, Slotted, Discrete Memoryless, Massive Access Channel (SAS-DM-MAC) in which the number of users, the number of messages, and the asynchronous window length grow exponentially with the coding blocklength...

(This article belongs to the Special Issue Wireless Networks: Information Theoretic Perspectives Ⅱ)
  • Article
  • Open Access
5 Citations
5,275 Views
21 Pages

Massive multiple-input and multiple-out (massive MIMO) systems and heterogeneous networks (HetNet) are envisioned to meet the new performance objectives of evolving networks. Now, the main challenge of massive MIMO with HetNet in two-tier networks is...

  • Article
  • Open Access
5 Citations
2,417 Views
15 Pages

Performance Optimization of Multipair Massive MIMO Polarized Relay Systems

  • Sian Xiong,
  • Zhipeng Chen,
  • Nan Jiang,
  • Jiahui Zhao and
  • Lingfeng Liu

In this paper, we analyze the challenges faced by multipair massive Multiple-input-multiple-output (MIMO) relay channels in 5G wireless communication systems, where high path loss and severe shadow fading between different user nodes can cause poor c...

  • Article
  • Open Access
17 Citations
5,028 Views
14 Pages

Data from geocryological studies of soil and rock massifs in permafrost zone are very important as a basis for predicting possible negative consequences associated with climate change. A promising technique for studying geocryological structures (var...

(This article belongs to the Special Issue Modern Surveying and Geophysical Methods for Soil and Rock)
  • Article
  • Open Access
4 Citations
3,345 Views
20 Pages

On Scalability of FDD-Based Cell-Free Massive MIMO Framework

  • Beenish Hassan,
  • Sobia Baig and
  • Saad Aslam

7 August 2023

Cell-free massive multiple-input multiple-output (MIMO) systems have the potential of providing joint services, including joint initial access, efficient clustering of access points (APs), and pilot allocation to user equipment (UEs) over large cover...

(This article belongs to the Section Communications)
  • Article
  • Open Access
1,892 Views
13 Pages

Measurement of Dried Seafloor Massive Sulfides

  • Malte Wichmann and
  • Andreas Hördt

27 June 2023

We carried out spectral-induced polarization (SIP) measurements on a set of dried seafloor massive sulfide samples and compared the results with those obtained with the same samples fully saturated with NaCl solution. We find that the conductivity an...

(This article belongs to the Special Issue Development of Geoelectrical and Electromagnetic Methods in Mineral Exploration)
  • Feature Paper
  • Article
  • Open Access
16 Citations
3,352 Views
19 Pages

Experimental Analysis of Concentrated versus Distributed Massive MIMO in an Indoor Cell at 3.5 GHz

  • Jesús R. Pérez,
  • Óscar Fernández,
  • Luis Valle,
  • Abla Bedoui and ,
  • Mohamed Et-tolba and
  • Rafael P. Torres
  • + 1 author+ 0 author

This paper presents a measurement-based comparison between distributed and concentrated massive multiple-input multiple-output (MIMO) systems, which are called D-mMIMO and C-mMIMO systems, in an indoor environment considering a 400 MHz bandwidth cent...

(This article belongs to the Special Issue Enabling-5G)
  • Article
  • Open Access
26 Citations
4,646 Views
12 Pages

Comparative Analysis of Data Detection Techniques for 5G Massive MIMO Systems

  • Mahmoud A. Albreem,
  • Arun Kumar,
  • Mohammed H. Alsharif,
  • Imran Khan and
  • Bong Jun Choi

9 November 2020

Massive multiple-input multiple-output (MIMO) is a backbone technology in the fifth-generation (5G) and beyond 5G (B5G) networks. It enhances performance gain, energy efficiency, and spectral efficiency. Unfortunately, a massive number of antennas ne...

(This article belongs to the Special Issue Developing 5G/6G Wireless Technologies for Sustainable Communication Systems)
  • Article
  • Open Access
25 Citations
6,230 Views
17 Pages

Low-Complexity Channel Estimation in 5G Massive MIMO-OFDM Systems

  • Omar A. Saraereh,
  • Imran Khan,
  • Qais Alsafasfeh,
  • Salem Alemaishat and
  • Sunghwan Kim

25 May 2019

Pilot contamination is the reuse of pilot signals, which is a bottleneck in massive multi-input multi-output (MIMO) systems as it varies directly with the numerous antennas, which are utilized by massive MIMO. This adversely impacts the channel state...

  • Extended Abstract
  • Open Access
1,781 Views
3 Pages

Channel Covariance Identification in FDD Massive MIMO Systems

  • José P. González-Coma,
  • Pedro Suárez-Casal,
  • Paula M. Castro and
  • Luis Castedo

19 September 2018

Channel estimation for Massive MIMO systems has drawn a lot of attention in the last years. A number of estimation methods rely on the knowledge of the channel covariance matrix to operate. However, this covariance is not known in practice, and it sh...

(This article belongs to the Proceedings of XoveTIC Congress 2018)
  • Article
  • Open Access
30 Citations
4,551 Views
22 Pages

Energy Efficient Design of Massive MIMO by Considering the Effects of Nonlinear Amplifiers

  • Arfat Ahmad Khan,
  • Peerapong Uthansakul,
  • Pumin Duangmanee and
  • Monthippa Uthansakul

24 April 2018

Massive Multiple-Input Multiple-Output (MIMO) alludes to the theory of having a large number of transmitter chains at the base station, which in turn provides the higher spectral and energy efficiency with reduced radiated power and greater simplicit...

  • Article
  • Open Access
10 Citations
4,286 Views
13 Pages

3 February 2022

In the user-centric, cell-free, massive multi-input, multi-output (MIMO) orthogonal frequency division multiplexing (OFDM) system, a large number of deployed access points (APs) serve user equipment (UEs) simultaneously, using the same time–fre...

  • Article
  • Open Access
8 Citations
4,357 Views
11 Pages

The conventional direction of arrival (DOA) estimation algorithm is not effective with the tremendous complexity due to the large-scale array antennas in a massive multiple-input multiple-output (MIMO) system. A new frame structure for downlink trans...

(This article belongs to the Special Issue Green Communications in Smart City)
  • Review
  • Open Access
5 Citations
2,170 Views
15 Pages

Spectropolarimetry for Discerning Geometry and Structure in Circumstellar Media of Hot Massive Stars

  • Richard Ignace,
  • Kenneth G. Gayley,
  • Roberto Casini,
  • Paul Scowen and ,
  • Christiana Erba and
  • Jeremy Drake
  • + 1 author+ 0 author

11 April 2025

Spectropolarimetric techniques are a mainstay of astrophysical inquiry, ranging from Solar System objects to the Cosmic Background Radiation. This review highlights applications of stellar polarimetry for massive hot stars, particularly in the contex...

(This article belongs to the Special Issue Circumstellar Matter in Hot Star Systems)
  • Article
  • Open Access
34 Citations
8,429 Views
17 Pages

16 May 2020

Multivariate time series with missing data is ubiquitous when the streaming data is collected by sensors or any other recording instruments. For instance, the outdoor sensors gathering different meteorological variables may encounter low material sen...

(This article belongs to the Section Intelligent Sensors)
  • Technical Note
  • Open Access
7 Citations
3,513 Views
12 Pages

6 February 2022

This paper presents an over-the-air testing method in which a full-rank channel matrix is created for a massive multiple-input multiple-output (MIMO) antenna system utilizing a fading emulator with a small number of scatterers. In the proposed method...

(This article belongs to the Topic Antennas)
  • Article
  • Open Access
2,383 Views
10 Pages

Cell-Free Massive MIMO Power Consumption with Serial Front-Hauls

  • Danaisy Prado-Alvarez,
  • Saúl Inca,
  • David Martín-Sacristán and
  • Jose F. Monserrat

11 October 2024

Massive MIMO deployments have been traditionally based on dedicated links in the front-haul, i.e., between the central processing units and the Access Points (APs). Recently, cell-free massive Multiple-Input Multiple-Output (MIMO) systems based on se...

  • Interesting Images
  • Open Access
1 Citations
3,012 Views
3 Pages

8 December 2022

Massive retinal gliosis (MRG) is a rare condition of non-neoplastic glial proliferation, which forms massive lesions that fill the eye. MRG is commonly associated with phthisis bulbi (a non-functional eye), congenital anomalies, or malformations. Her...

(This article belongs to the Special Issue Current Diagnostic Concepts of Eye Pathology)
  • Article
  • Open Access
2 Citations
3,739 Views
19 Pages

Massive Education in Prison Health in Brazil: A Look Beyond the Walls

  • Janaina L. R. da S. Valentim,
  • Sara Dias-Trindade,
  • Aline de P. Dias,
  • Alexandre R. Caitano and ,
  • Laysa G. de S. Nunes,
  • Manoel H. Romão,
  • Felipe Fernandes,
  • Nícolas V. R. Veras,
  • Kelson C. Medeiros and
  • Ricardo A. M. Valentim
  • + 11 authors+ 6 authors

Equal access to health initiatives and services under the principles of universal and comprehensive care remains a challenge in Brazil. The realization of public health policies is further intricate when one examines the health situation of people de...

  • Article
  • Open Access
30 Citations
4,298 Views
19 Pages

11 June 2019

Millimeter Wave (mmWave) Massive Multiple Input Multiple Output (MIMO) has been a promising candidate for the current and next generation of cellular networks. The hybrid analogue/digital precoding will be a crucial ingredient in the mmWave cellular...

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