Saqer S. Alja’Afreh^1,*, Mallak H. Alshamaileh¹, Eqab Almajali², Jawad Yousaf³, Amir Altaf⁴

CMC-Computers, Materials & Continua, Vol.73, No.2, pp. 3181-3198, 2022, DOI:10.32604/cmc.2022.029863 - 16 June 2022

Abstract Due to the limited space and large mutual coupling levels, the design of sub-6 GHz massive Multi-Input Multi-Output (m-MIMO) smartphone antenna system attracts antennas’ designers and engineers worldwide. Therefore, this paper presents 18-element m-MIMO antenna system that covers the long-term evolution 42 (LTE42) frequency band (3.4–3.6 GHz) for the fifth generation (5G) applications in metallic frame smartphones. The proposed array system is etched on the long sides of a metal rim of the mobile chassis symmetrically, which is electrically connected to the system ground plane with zero ground clearance. A low-profile frame of height 7… More >

Apinya Innok¹, Chittapon Keawin², Peerapong Uthansakul^2,*

CMC-Computers, Materials & Continua, Vol.73, No.1, pp. 103-118, 2022, DOI:10.32604/cmc.2022.027106 - 18 May 2022

Abstract In communication channel estimation, the Least Square (LS) technique has long been a widely accepted and commonly used principle. This is because the simple calculation method is compared with other channel estimation methods. The Minimum Mean Squares Error (MMSE), which is developed later, is devised as the next step because the goal is to reduce the error rate in the communication system from the conventional LS technique which still has a higher error rate. These channel estimations are very important to modern communication systems, especially massive MIMO. Evaluating the massive MIMO channel is one of… More >

Jung-In Baik, Ji-Hwan Kim, Beom-Sik Shin, Ji-Hye Oh, Hyoung-Kyu Song^*

CMC-Computers, Materials & Continua, Vol.72, No.3, pp. 5807-5821, 2022, DOI:10.32604/cmc.2022.028434 - 21 April 2022

Abstract With the rapid evolution of Internet of things (IoT), many edge devices require simultaneous connection in 5G communication era. To afford massive data of IoT devices, multiple input multiple output non-orthogonal multiple access (MIMO-NOMA) method has been considered as a promising technology. However, there are numerous drawbacks due to error propagation and inter-user interferences. Therefore, proposed scheme aims to improve the reliability of the MIMO-NOMA system with digital beamforming and intra-cluster cooperative multi point (CoMP) to efficiently support IoT system. In the conventional MIMO-NOMA system, user entities are grouped into clusters. Block diagonalization (BD) is… More >

Ayman Massaoudi^*, Abdelwahed Berguiga, Ahlem Harchay

CMC-Computers, Materials & Continua, Vol.72, No.3, pp. 4663-4673, 2022, DOI:10.32604/cmc.2022.026972 - 21 April 2022

Abstract Smart irrigation system, also referred as precision irrigation system, is an attractive solution to save the limited water resources as well as to improve crop productivity and quality. In this work, by using Internet of things (IoT), we aim to design a smart irrigation system for olive groves. In such IoT system, a huge number of low-power and low-complexity devices (sensors, actuators) are interconnected. Thus, a great challenge is to satisfy the increasing demands in terms of spectral efficiency. Moreover, securing the IoT system is also a critical challenge, since several types of cybersecurity threats More >

Waleed Shahjehan¹, Abid Ullah¹, Syed Waqar Shah¹, Imran Khan¹, Nor Samsiah Sani², Ki-Il Kim^3,*

CMC-Computers, Materials & Continua, Vol.72, No.2, pp. 2797-2810, 2022, DOI:10.32604/cmc.2022.026185 - 29 March 2022

Abstract Millimeter-Wave (mmWave) Massive MIMO is one of the most effective technology for the fifth-generation (5G) wireless networks. It improves both the spectral and energy efficiency by utilizing the 30–300 GHz millimeter-wave bandwidth and a large number of antennas at the base station. However, increasing the number of antennas requires a large number of radio frequency (RF) chains which results in high power consumption. In order to reduce the RF chain's energy, cost and provide desirable quality-of-service (QoS) to the subscribers, this paper proposes an energy-efficient hybrid precoding algorithm for mmWave massive MIMO networks based on More >

L. Vasanth^*, N. J. R. Muniraj

Intelligent Automation & Soft Computing, Vol.33, No.2, pp. 955-966, 2022, DOI:10.32604/iasc.2022.022979 - 08 February 2022

Abstract Multiple Input Multiple Output (MIMO) is an advanced communication technology that is often used for secure data transfer for military and other applications while transmitting data with high error and noise. To address this issue, a step-by-step hybrid Quadrature Phase Shift Keying (QPSK) modulation scheme in the MIMO system for a complex Very Large-Scale Integration (VLSI) format is recommended. When compared to Binary Phase Shift Keying (BPSK), this approach provides twice the data rate while using half the bandwidth. The complexity is lowered through multiplication and addition, as well as error and noise reduction in More >

Muhannad Y. Muhsin^1,*, Ali J. Salim², Jawad K. Ali²

Computer Systems Science and Engineering, Vol.42, No.3, pp. 919-934, 2022, DOI:10.32604/csse.2022.023102 - 08 February 2022

Abstract A compact self-isolated Multi Input Multi Output (MIMO) antenna array is presented for 5G mobile phone devices. The proposed antenna system is operating at the 3.5 GHz band (3400–3600 MHz) and consists of eight antenna elements placed along two side edges of a mobile device, which meets the current trend requirements of full-screen smartphone devices. Each antenna element is divided into two parts, a front part and back part. The front part consists of an I-shaped feeding line and a modified Hilbert fractal monopole antenna, whereas the back part is an L-shaped element shorted to… More >

Kyu-haeng Lee^*

CMC-Computers, Materials & Continua, Vol.71, No.3, pp. 5561-5580, 2022, DOI:10.32604/cmc.2022.024562 - 14 January 2022

Abstract Recently, as deep learning technologies have received much attention for their great potential in extracting the principal components of data, there have been many efforts to apply them to the Channel State Information (CSI) feedback overhead problem, which can significantly limit Multi-Input Multi-Output (MIMO) beamforming gains. Unfortunately, since most compression models can quickly become outdated due to channel variation, timely model updates are essential for reflecting the current channel conditions, resulting in frequent additional transmissions for model sharing between transceivers. In particular, the heavy network models employed by most previous studies to achieve high compression… More >

Waleed Shahjehan¹, Abid Ullah¹, Syed Waqar Shah¹, Ayman A. Aly², Bassem F. Felemban², Wonjong Noh^3,*

CMC-Computers, Materials & Continua, Vol.71, No.3, pp. 5399-5411, 2022, DOI:10.32604/cmc.2022.022034 - 14 January 2022

Abstract Millimeter wave communication works in the 30–300 GHz frequency range, and can obtain a very high bandwidth, which greatly improves the transmission rate of the communication system and becomes one of the key technologies of fifth-generation (5G). The smaller wavelength of the millimeter wave makes it possible to assemble a large number of antennas in a small aperture. The resulting array gain can compensate for the path loss of the millimeter wave. Utilizing this feature, the millimeter wave massive multiple-input multiple-output (MIMO) system uses a large antenna array at the base station. It enables the… More >

Farung Samklang, Peerapong Uthansakul, Monthippa Uthansakul^*, Patikorn Anchuen

CMC-Computers, Materials & Continua, Vol.71, No.1, pp. 1887-1902, 2022, DOI:10.32604/cmc.2022.022139 - 03 November 2021

Abstract Precoding is a beamforming technique that supports multi-stream transmission in which the RF chain plays a significant role as a digital precoding at the receiver for wireless communication. The traditional precoding contains only digital signal processing and each antenna connects to each RF chain, which provides high transmission efficiency but high cost and hardware complexity. Hybrid precoding is one of the most popular massive multiple input multiple output (MIMO) techniques that can save costs and avoid using complex hardware. At present, network services are currently in focus with a wide range of traffic volumes. In… More >