Abstract— The communication industry is making rapid strides toward the implementation of 5G and beyond 5G (B5G) wireless technology. New applications are being developed in order to fulfil the ever-increasing demand for faster data rates as well as increased service quality (Quality Of Service). These new applications require wireless connectivity that possesses a massive increase in data rates, a significant decrease in latency, and widespread public acceptance for a large number of devices. The non-orthogonal multiple access (NOMA) protocol, which is a key component of the family of protocols known as the next-generation multiple access (NGMA), has recently come to be acknowledged as a viable multiple access option for sixth-generation (6G) networks. In this article, we will discuss the different 6G dimensions that are available. The primary objective of this paper is to present fundamental ideas on multiple access that are necessary for B5G communication, to discuss recent research developments on significant technologies, and to provide research and development guidelines for NOMA in mobile communication systems that go beyond 5G communication networks.

Keywords—  6G, Artificial Intelligence (AI), Intelligent Reflecting Surfaces (IRS), Machine learning, non-orthogonal multiple access (NOMA), successive interference cancellation (SIC).