This paper investigates the performance of nonorthogonal multiple access (NOMA) based hybrid satelliteunmanned aerial vehicle (UAV) systems, where a low Earth orbit (LEO) satellite communicates with the ground users via a decode and forward (DF) UAV relay. We investigate a two NOMA users system, where a far user (FU) and a near user (NU) are served by the UAV which is located at a certain height above the origin of the coverage circle. The channel between satellite and UAV is assumed to follow a Shadowed-Rician fading and the channels between UAV and users are assumed to follow a Nakagami-m fading. New closedform expressions of the outage probabilities for the two users and the system are derived. Different from other work in literature, we take into consideration different parameters affecting the total link budget. Additionally, we propose an algorithm for minimizing the system outage probability. The mathematical analysis is verified by extensive representative Monte-Carlo (MC) simulations. Finally, simulations are provided to demonstrate the impact of important parameters on the considered system as well as the superiority of the NOMA scheme the over reference scheme.
Abstract-Recent technical advancements in low-power integrated circuits, ultra low-power RF (radio frequency) technology, wireless communications and micro sensors allowed the realization of a futuristic health care system called Wireless Body Area Networks (WBANs). This new type of technology hold much promise for future patient health monitoring. A body area network wirelessly connects independent nodes (e.g. medical devices, earphones, sensors, actuators) attached to the body surface, implanted into tissues/body, or dispersed in the clothing for applications in home/health care, sports, entertainment, defense, ambient intelligence, pervasive computing and many other areas. These sensors offer promising applications in areas such as real time health monitoring, interactive gaming and consumer electronics. WBAN does not compel the patient to stay in the hospital thereby giving much physical mobility. This paper presents an overview on the various aspects of WBAN including the importance of context awareness in body area networks, applications of WBANs, major security requirements for data security and privacy in WBAN and various research challenges existing in this area Index Terms-Wireless body area network, WBAN, body area network, real time health monitoring, bio sensors, context-awareness, data security and privacy.
The Open Radio Access Network (O-RAN) architecture has been identified as a promising technology for enhanced network deployment, innovation, improved competition, and reduction of capital and operating expenses (CAPEX/OPEX) of 5G and beyond networks because of its open interfaces, disaggregated network entities and functions, virtualization of network hardware and software, and intelligent control. However, the effect of this improved technology on the energy consumption of the RAN needs to be carefully investigated, so that the many advantages that can be obtained from the O-RAN are not overwhelmed by increased energy consumption. Hence, in this paper, we investigate the O-RAN from an Energy efficiency (EE) perspective by reviewing the state-of-the-art power consumption models, and EE techniques that have been proposed to minimize the energy consumption of O-RAN. In addition, the challenges associated with the optimization of the EE of O-RAN and opportunities for further research are highlighted.
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