One of the most dynamic and quickly expanding technology subfields within the communication industry is wireless communication. To be able to improve interaction between users and base stations, multiple access techniques must be employed. These various access techniques can be categorised broadly into two categories: non-orthogonal multiple access techniques and orthogonal multiple access techniques. We employed a variety of OMA strategies in 1G-TDMA, 2G-FDMA, 3G-CDMA, and 4G-OFDMA, among other generations. In the context of next-generation wireless technology, researchers aim to introduce the Non-Orthogonal Multiple Access (NOMA) technique to enhance reliability and facilitate multi-user access.