Contents I. Introduction
Orthogonal multiple access (OMA) technique is channel dependent technique i.e., for better channel condition its performance is good while for poor channel condition its performance degrades [1]. Generation of large number of orthogonal signal is also difficult so for future mobile networks, Non-orthogonal multiple access technique (NOMA) identified as a optimistic multiple access technique [2]. NOMA enhances spectrum efficiency by assigning numerous user to a single resource block. Therefore, It has been suggested as an alternative approach for future wireless systems [3]. The primary goal of NOMA is to enhance system capacity by allowing multiple users to share a single resource block. For this motive, NOMA has been identified to be able to solve this problem. NOMA is classified into two types i.e., code domain NOMA and power domain NOMA [4].
