A Systematic Review of NOMA Variants for 5G and Beyond

With the fast expansion of the Internet of Things (IoT), there is an exponential need for mobile intelligent terminals .However, the connectivity of large-scale intelligent terminals is constrained by increasingly restricted spectrum resources. To address this issue, non-orthogonal multiple access (NOMA) technology, which can handle more users with less resources, is predicted to enable future wireless networks beyond 5G,., 6G, to give huge terminal access. The fundamental idea behind NOMA is to superimpose signals from numerous users on the same time-frequency resource prior to transmission. At the receiver, serial interference cancellation (SIC) technology is used to reduce interference among users. In this  review paper  we discusses the principles of the strong candidate Non-Orthogonal Multiple Access (NOMA) approach, as well as how it can best match the requirements of the Fifth Generation (5G) requirements in practical applications.  

Optical Non-Orthogonal Multiple Access for Visible Light Communication

The proliferation of mobile Internet and connected devices, offering a variety of services at different levels of performance, represents a major challenge for the fifth generation wireless networks and beyond. This requires a paradigm shift towards the development of key enabling techniques for the next generation wireless networks. In this respect, visible light communication (VLC) has recently emerged as a new communication paradigm that is capable of providing ubiquitous connectivity by complementing radio frequency communications. One of the main challenges of VLC systems, however, is the low modulation bandwidth of the light-emitting-diodes, which is in the megahertz range. This article presents a promising technology, referred to as "optical- non-orthogonal multiple access (O-NOMA)", which is envisioned to address the key challenges in the next generation of wireless networks. We provide a detailed overview and analysis of the state-of-the-art integration of O-NOMA in VLC networks. Furthermore, we provide insights on the potential opportunities and challenges as well as some open research problems that are envisioned to pave the way for the future design and implementation of O-NOMA in VLC systems