Haithem Ben Chikha, Ahmad Almadhor^*

CMC-Computers, Materials & Continua, Vol.70, No.1, pp. 1799-1814, 2022, DOI:10.32604/cmc.2022.018819 - 07 September 2021

Abstract To promote reliable and secure communications in the cognitive radio network, the automatic modulation classification algorithms have been mainly proposed to estimate a single modulation. In this paper, we address the classification of superimposed modulations dedicated to 5G multiple-input multiple-output (MIMO) two-way cognitive relay network in realistic channels modeled with Nakagami- distribution. Our purpose consists of classifying pairs of users modulations from superimposed signals. To achieve this goal, we apply the higher-order statistics in conjunction with the MultiBoostAB classifier. We use several efficiency metrics including the true positive (TP) rate, false positive (FP) rate, precision,… More >

T. Prabhu^1,*, S. Chenthur Pandian²

CMC-Computers, Materials & Continua, Vol.69, No.2, pp. 2549-2562, 2021, DOI:10.32604/cmc.2021.018793 - 21 July 2021

Abstract This paper proposes, demonstrates, and describes a basic T-shaped Multi-Input and Multi-Output (MIMO) antenna with a resonant frequency of 3.1 to 10.6 GHz. Compared with the U-shaped antenna, the mutual coupling is minimized by using a T-shaped patch antenna. The T-shaped patch antenna shapes filter properties are tested to achieve separation over the 3.1 to 10.6 GHz frequency range. The parametric analysis, including width, duration, and spacing, is designed in the MIMO applications for good isolation. On the FR4 substratum, the configuration of MIMO is simulated. The appropriate dielectric material ɛ_r = 4.4 is introduced using More >

Yu-Jin Na¹, Ji-Sung Jung¹, Young-Hwan You², Hyoung-Kyu Song^1,*

CMC-Computers, Materials & Continua, Vol.69, No.1, pp. 1361-1373, 2021, DOI:10.32604/cmc.2021.018481 - 04 June 2021

Abstract As the installation of small cells increases, the use of relay also increases. The relay operates as a base station as well as just an amplifier. As the roles and types of relays become more diverse, appropriate relay selection technology is an effective way to improve communication performance. Many researches for relay selection have been studied to secure the reliability of relay communication. In this paper, the relay selection scheme is proposed for a cooperative system using decode-and-forward (DF) relaying scheme in the mobile communication system. To maintain the transmission rate, the proposed scheme classifies… More >

Ayman Abdulhadi Althuwayb¹, Fazirulhisyam Hashim², Jiun Terng Liew², Imran Khan³, Jeong Woo Lee⁴, Emmanuel Ampoma Affum⁵, Abdeldjalil Ouahabi^6,7,*, Sébastien Jacques⁸

CMC-Computers, Materials & Continua, Vol.69, No.1, pp. 679-694, 2021, DOI:10.32604/cmc.2021.015421 - 04 June 2021

Abstract With the rapid development of the mobile internet and the internet of things (IoT), the fifth generation (5G) mobile communication system is seeing explosive growth in data traffic. In addition, low-frequency spectrum resources are becoming increasingly scarce and there is now an urgent need to switch to higher frequency bands. Millimeter wave (mmWave) technology has several outstanding features—it is one of the most well-known 5G technologies and has the capacity to fulfil many of the requirements of future wireless networks. Importantly, it has an abundant resource spectrum, which can significantly increase the communication rate of… More >

Shahid Bashir¹, Imran Khan², Fahd N. Al-Wesabi³, Nadhem Nemri³, Ammar Zahary⁴, Quang Ngoc Nguyen^5,*

CMC-Computers, Materials & Continua, Vol.68, No.3, pp. 3029-3044, 2021, DOI:10.32604/cmc.2021.017015 - 06 May 2021

Abstract The device-to-device (D2D) networking technology is extended to the conventional cellular network to boost the communication efficiency of the entire network, forming a heterogeneous 5G and beyond (B5G) communication network. D2D communication in a cellular cell will boost the efficiency of the spectrum, increase the ability of the device, and reduce the communication burden of base stations through the sharing of approved cell resources, causing serious interference as well. The device-to-device (D2D) networking technology is extended to the conventional cellular network to boost the communication efficiency of the entire network, forming a heterogeneous 5G communication… More >

Latif Jan¹, Mohammad Haseeb Zafar¹, Abdul Waheed², Mahdi Zareei³, Faisal Alanazi^4,*

CMC-Computers, Materials & Continua, Vol.68, No.3, pp. 3133-3145, 2021, DOI:10.32604/cmc.2021.014857 - 06 May 2021

Abstract Spatial diversity plays a significant role in wireless communication systems, including the Fourth Generation (4G) and Fifth Generation (5G) systems, and it is expected to be a fundamental part of the future wireless communication systems as well. The Multiple-Input Multiple-Output (MIMO) technology, which is included in the IEEE 802.16j standard, still holds the most crucial position in the 4G spectrum as it promises to improve the throughput, capacity, spectral, and energy efficiency of wireless communication systems in the 2020s. This makes MIMO a viable technology for delay constrained medical and health care facilities. This paper… More >

Seulgi Lee¹, Ji-Sung Jung¹, Young-Hwan You², Hyoung-Kyu Song^1,*

CMC-Computers, Materials & Continua, Vol.68, No.2, pp. 2205-2219, 2021, DOI:10.32604/cmc.2021.017008 - 13 April 2021

Abstract This paper proposes an improved hybrid beamforming system based on multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) system. The proposed beamforming system improves energy efficiency compared to the conventional hybrid beamforming system. Both sub-connected and full-connected structure are considered to apply the proposed algorithm. In the conventional hybrid beamforming, the usage of radio frequency (RF) chains and phase shifter (PS) gives high power and hardware complexity. In this paper, the phase over sampling (POS) with switches (SW) is used in hybrid beamforming system to improve the energy efficiency. The POS-SW structure samples the value of… More >

Park Chan-Yeob, Hyun-Ro Jae, Jun-Yong Jang, Song Hyoung-Kyu^*

CMC-Computers, Materials & Continua, Vol.68, No.1, pp. 137-148, 2021, DOI:10.32604/cmc.2021.016108 - 22 March 2021

Abstract Linear precoding methods such as zero-forcing (ZF) are near optimal for downlink massive multi-user multiple input multiple output (MIMO) systems due to their asymptotic channel property. However, as the number of users increases, the computational complexity of obtaining the inverse matrix of the gram matrix increases. For solving the computational complexity problem, this paper proposes an improved Jacobi (JC)-based precoder to improve error performance of the conventional JC in the downlink massive MIMO systems. The conventional JC was studied for solving the high computational complexity of the ZF algorithm and was able to achieve parallel… More >

Ji-Sung Jung¹, Won-Seok Lee¹, Yeong-Rong Lee¹, Jaeho Kim², Hyoung-Kyu Song^1,*

CMC-Computers, Materials & Continua, Vol.67, No.3, pp. 3057-3070, 2021, DOI:10.32604/cmc.2021.015673 - 01 March 2021

Abstract Massive multiple input multiple output (MIMO) has become essential for the increase of capacity as the millimeter-wave (mmWave) communication is considered. Also, hybrid beamforming systems have been studied since full-digital beamforming is impractical due to high cost and power consumption of the radio frequency (RF) chains. This paper proposes a hybrid beamforming scheme to improve the spectral efficiency for multi-user MIMO (MU-MIMO) systems. In a frequency selective fading environment, hybrid beamforming schemes suffer from performance degradation since the analog precoder performs the same precoding for all subcarriers. To mitigate performance degradation, this paper uses the… More >

Adeeb Salh¹, Lukman Audah^1,*, Qazwan Abdullah¹, Nor Shahida M. Shah², Shipun A. Hamzah¹, Shahilah Nordin³, Nabil Farah²

CMC-Computers, Materials & Continua, Vol.67, No.3, pp. 3189-3214, 2021, DOI:10.32604/cmc.2021.014746 - 01 March 2021

Abstract Energy efficiency (EE) is a critical design when taking into account circuit power consumption (CPC) in fifth-generation cellular networks. These problems arise because of the increasing number of antennas in massive multiple-input multiple-output (MIMO) systems, attributable to inter-cell interference for channel state information. Apart from that, a higher number of radio frequency (RF) chains at the base station and active users consume more power due to the processing activities in digital-to-analogue converters and power amplifiers. Therefore, antenna selection, user selection, optimal transmission power, and pilot reuse power are important aspects in improving energy efficiency in… More >