This article represents a comparative study of various types of multiple users' access schemes for cellular radio system. One of the promising technique for the significant bandwidth efficiency enhancement in future wireless cellular system compared to the conventional multiple access technologies, especially orthogonal multiple access is Non-Orthogonal multiple access(NOMA). NOMA have grater spectral efficiency and more massive connectivity over orthogonal in fading environment. Third

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... n partnership projects have recently been proposed NOMA for 4G (3GPP-LTE-A). It is a Novel technique focusing the solution for 5G, advanced multimedia applications and Internet of things in terms of supporting massive heterogeneous data traffic. This review paper primarily focus on diverse NOMA techniques and provides a detailed outline of the Cutting edge in NOMA basic principles, NOMA power domain and its other variants.