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 >

Jun-Yong Jang¹, Won-Seok Lee¹, Jae-Hyun Ro¹, Young-Hawn You², Hyoung-Kyu Song^1,*

CMC-Computers, Materials & Continua, Vol.67, No.2, pp. 1729-1745, 2021, DOI:10.32604/cmc.2021.015424 - 05 February 2021

Abstract In this paper, a novel precoding scheme based on the Gauss-Seidel (GS) method is proposed for downlink massive multiple-input multiple-output (MIMO) systems. The GS method iteratively approximates the matrix inversion and reduces the overall complexity of the precoding process. In addition, the GS method shows a fast convergence rate to the Zero-forcing (ZF) method that requires an exact invertible matrix. However, to satisfy demanded error performance and converge to the error performance of the ZF method in the practical condition such as spatially correlated channels, more iterations are necessary for the GS method and increase… More >