Xingwang Li^1,2, Hua Pang¹, Geng Li^1,*, Junjie Jiang¹, Hui Zhang³, Changfei Gu⁴, Dong Yuan⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.139, No.2, pp. 1135-1166, 2024, DOI:10.32604/cmes.2023.031534

Abstract The development of the fifth-generation (5G) mobile communication systems has entered the commercialization stage. 5G has a high data rate, low latency, and high reliability that can meet the basic demands of most industries and daily life, such as the Internet of Things (IoT), intelligent transportation systems, positioning, and navigation. The continuous progress and development of society have aroused wide concern. Positioning accuracy is the core demand for the applications, especially in complex environments such as airports, warehouses, supermarkets, and basements. However, many factors also affect the accuracy of positioning in those environments, for example, multipath effects, non-line-of-sight, and clock… More >

Ping Li¹, Kefeng Guo^2,*, Feng Zhou¹, Xueling Wang³, Yuzhen Huang⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.138, No.2, pp. 1849-1864, 2024, DOI:10.32604/cmes.2023.029801

Abstract Integrated satellite unmanned aerial vehicle relay networks (ISUAVRNs) have become a prominent topic in recent years. This paper investigates the average secrecy capacity (ASC) for reconfigurable intelligent surface (RIS)-enabled ISUAVRNs. Especially, an eve is considered to intercept the legitimate information from the considered secrecy system. Besides, we get detailed expressions for the ASC of the regarded secrecy system with the aid of the reconfigurable intelligent. Furthermore, to gain insightful results of the major parameters on the ASC in high signal-to-noise ratio regime, the approximate investigations are further gotten, which give an efficient method to value the secrecy analysis. At last,… More >

Xianli Gong¹, Chongwen Huang^2,3,4, Xinwei Yue⁵, Zhaohui Yang^2,4,6, Feng Liu^1,*

CMES-Computer Modeling in Engineering & Sciences, Vol.135, No.3, pp. 2531-2555, 2023, DOI:10.32604/cmes.2023.024940

Abstract In this paper, we consider a downlink non-orthogonal multiple access (NOMA) network assisted by two reconfigurable intelligent surfaces (RISs) over Rician fading channels, in which each user communicates with the base station by the virtue of a RIS to enhance the reliability of the received signal. To evaluate the system performance of our proposed RIS-NOMA network, we first derive the exact and asymptotic expressions for the outage probability and ergodic rate of two users. Then, we derive the exact and asymptotic upper bound expressions for the ergodic rate of the nearby user. Based on asymptotic analytical results, the diversity orders… More >