Haibo Wang¹, Hongwei Gao^1,*, Pai Jiang¹, Matthieu De Mari², Panzer Gu³, Yinsheng Liu¹

Journal on Internet of Things, Vol.6, pp. 17-41, 2024, DOI:10.32604/jiot.2024.054791 - 26 August 2024

Abstract In the 6G Internet of Things (IoT) paradigm, unprecedented challenges will be raised to provide massive connectivity, ultra-low latency, and energy efficiency for ultra-dense IoT devices. To address these challenges, we explore the non-orthogonal multiple access (NOMA) based grant-free random access (GFRA) schemes in the cellular uplink to support massive IoT devices with high spectrum efficiency and low access latency. In particular, we focus on optimizing the backoff strategy of each device when transmitting time-sensitive data samples to a multiple-input multiple-output (MIMO)-enabled base station subject to energy constraints. To cope with the dynamic varied channel… More >

Baofeng Ji^1,2,3,4,*, Yifan Liu^1,2,3,4, Tingpeng Li¹, Ling Xing², Weixing Wang², Shahid Mumtaz⁵, Xiaolong Shang⁶, Wanying Liu², Congzheng Han⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.138, No.1, pp. 679-689, 2024, DOI:10.32604/cmes.2023.028667 - 22 September 2023

Abstract With the development of information technology, more and more devices are connected to the Internet through wireless communication to complete data interconnection. Due to the broadcast characteristics of wireless channels, wireless networks have suffered more and more malicious attacks. Physical layer security has received extensive attention from industry and academia. MIMO is considered to be one of the most important technologies related to physical layer security. Through beamforming technology, messages can be transmitted to legitimate users in an offset direction that is as orthogonal as possible to the interference channel to ensure the reception SINR… More >

Amit V. Patel¹, Arpan Desai¹, Issa Elfergani^2,3,*, Hiren Mewada⁴, Chemseddine Zebiri⁵, Keyur Mahant¹, Jonathan Rodriguez², Raed Abd-Alhameed³

CMES-Computer Modeling in Engineering & Sciences, Vol.137, No.3, pp. 2867-2879, 2023, DOI:10.32604/cmes.2023.026200 - 03 August 2023

Abstract A four-element compact dual-band patch antenna having a common ground plane operating at 28/38 GHz is proposed for millimeter-wave communication systems in this paper. The multiple-input-multiple-output (MIMO) antenna geometry consists of a slotted ellipse enclosed within a hollow circle which is orthogonally rotated with a connected partial ground at the back. The overall size of the four elements MIMO antenna is 2.24λ × 2.24λ (at 27.12 GHz). The prototype of four-element MIMO resonator is designed and printed using Rogers RT Duroid 5880 with ε_r = 2.2 and loss tangent = 0.0009 and having a thickness of More >

Elsaid Md. Abdelrahim^1,2, Mona Alduailij³, Mai Alduailij³, Romany F. Mansour^4,*, Osama A. Ghoneim⁵

Computer Systems Science and Engineering, Vol.47, No.2, pp. 1493-1505, 2023, DOI:10.32604/csse.2023.037976 - 28 July 2023

Abstract Massive multiple-input multiple-output (MIMO) systems that use the millimeter-wave (mm-wave) band have a higher frequency and more antennas, which leads to significant path loss, high power consumption, and server interference. Due to these issues, the spectrum efficiency is significantly reduced, making spectral efficiency improvement an important research topic for 5G communication. Together with communication in the terahertz (THz) bands, mmWave communication is currently a component of the 5G standards and is seen as a solution to the commercial bandwidth shortage. The quantity of continuous, mostly untapped bandwidth in the 30–300 GHz band has presented a rare… More >

Xiaoli Jing, Xianpeng Wang^*, Xiang Lan, Ting Su

CMES-Computer Modeling in Engineering & Sciences, Vol.137, No.2, pp. 1789-1804, 2023, DOI:10.32604/cmes.2023.028477 - 26 June 2023

Abstract At present, the traditional channel estimation algorithms have the disadvantages of over-reliance on initial conditions and high complexity. The bacterial foraging optimization (BFO)-based algorithm has been applied in wireless communication and signal processing because of its simple operation and strong self-organization ability. But the BFO-based algorithm is easy to fall into local optimum. Therefore, this paper proposes the quantum bacterial foraging optimization (QBFO)-binary orthogonal matching pursuit (BOMP) channel estimation algorithm to the problem of local optimization. Firstly, the binary matrix is constructed according to whether atoms are selected or not. And the support set of… More >

A. Richard William^1,*, J. Senthilkumar², Y. Suresh², V. Mohanraj²

Computer Systems Science and Engineering, Vol.47, No.1, pp. 777-790, 2023, DOI:10.32604/csse.2023.031753 - 26 May 2023

Abstract In cloud computing Resource allocation is a very complex task. Handling the customer demand makes the challenges of on-demand resource allocation. Many challenges are faced by conventional methods for resource allocation in order to meet the Quality of Service (QoS) requirements of users. For solving the about said problems a new method was implemented with the utility of machine learning framework of resource allocation by utilizing the cloud computing technique was taken in to an account in this research work. The accuracy in the machine learning algorithm can be improved by introducing Bat Algorithm with… More >

Weiqiang Tan^1,*, Quanquan Zhou¹, Weijie Tan², Longcheng Yang³, Chunguo Li⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.137, No.1, pp. 775-787, 2023, DOI:10.32604/cmes.2023.027427 - 23 April 2023

Abstract In this paper, we investigate the end-to-end performance of intelligent reflecting surface (IRS)-assisted wireless communication systems. We consider a system in which an IRS is deployed on a uniform planar array (UPA) configuration, including a large number of reflecting elements, where the transmitters and receivers are only equipped with a single antenna. Our objective is to analytically obtain the achievable ergodic rate, outage probability, and bit error rate (BER) of the system. Furthermore, to maximize the system’s signal-to-noise ratio (SNR), we design the phase shift of each reflecting element and derive the optimal reflection phase… More > Graphic Abstract

Ramya Sridhar^1,*, Vijayalakshimi Patteeswaran²

Computer Systems Science and Engineering, Vol.46, No.2, pp. 2109-2122, 2023, DOI:10.32604/csse.2023.036781 - 09 February 2023

Abstract In this paper, the investigation of a novel compact 2 × 2, 2 × 1, and 1 × 1 Ultra-Wide Band (UWB) based Multiple-Input Multiple-Output (MIMO) antenna with Defected Ground Structure (DGS) is employed. The proposed Electromagnetic Radiation Structures (ERS) is composed of multiple radiating elements. These MIMO antennas are designed and analyzed with and without DGS. The feeding is introduced by a microstrip-fed line to significantly moderate the radiating structure’s overall size, which is 60 × 40 × 1 mm. The high directivity and divergence characteristics are attained by introducing the microstrip-fed lines perpendicular… More >

K. Jayanthi^1,*, A. M. Kalpana²

Computer Systems Science and Engineering, Vol.46, No.2, pp. 1689-1705, 2023, DOI:10.32604/csse.2023.034613 - 09 February 2023

Abstract The fifth-generation (5G) wireless technology is the most recent standardization in communication services of interest across the globe. The concept of Multiple-Input-Multiple-Output antenna (MIMO) systems has recently been incorporated to operate at higher frequencies without limitations. This paper addresses, design of a high-gain MIMO antenna that offers a bandwidth of 400 MHz and 2.58 GHz by resonating at 28 and 38 GHz, respectively for 5G millimeter (mm)-wave applications. The proposed design is developed on a RT Duroid 5880 substrate with a single elemental dimension of 9.53 × 7.85 × 0.8 mm³. The patch antenna is fully grounded and is fed with More >

Mahmoud A. Abdelghany^1,4, Mohamed Fathy Abo Sree², Arpan Desai³, Ahmed A. Ibrahim^4,*

CMES-Computer Modeling in Engineering & Sciences, Vol.136, No.2, pp. 1999-2015, 2023, DOI:10.32604/cmes.2023.023643 - 06 February 2023

Abstract A 4-port multiple-input multiple-output (MIMO) antenna exhibiting low mutual coupling and UWB performance is developed. The octagonal-shaped four-antenna elements are connected with a 50 Ω microstrip feed line that is arranged rotationally to achieve the orthogonal polarization for improving the MIMO system performance. The antenna has a wideband impedance bandwidth of 7.5 GHz with S₁₁ < −10 dB from (103.44%) 3.5–11 GHz and inter-element isolation higher than 20 dB. Antenna validation is carried out by verifying the simulated and measured results after fabricating the antenna. The results in the form of omnidirectional radiation patterns, peak gain (≥4 dBi), and Envelope Correlation Coefficient (ECC) (≤0.01) More > Graphic Abstract