The Key Technological Developments of Non-Orthogonal Multiple Access (NOMA) in 5G Cellular Networks

With the evolution of cellular networks, the shortage of spectrum resources remains a vital limitation for the technology. In the application of 5G, traditional Orthogonal Frequency Division Multiple Access (OFDMA) technology cannot meet the technical specifications of R17. NOMA technology introduces interference information to allow spectrum resource sharing between mass users. Therefore it improves the capacity and efficiency of the channel and is valued for its immense potential for 5G future development. This paper mainly focuses on NOMA technology. Firstly the paper introduces the technology’s working principles and design concepts, then respectively elaborates on the basic principle of three mainstream technical solutions under this approach. The three technologies are MUSA, SCMA, and PDMA. The paper pointed out that NOMA realizes a non-orthogonal multi-user shared spectrum by introducing interference to differentiate different users on the same frequency resources. NOMA possesses excellent scalability and potential for enhancement, offering improved performance compared to the previous generation. However, meanwhile, the technology also faces drawbacks such as a high bit error rate under high resource utilization and limited performance improvement under low utilization. Future development of NOMA technology should mainly focus on optimizing and simplifying the code to enhance various performances. The technology can also integrate with other mature technologies for broader practical implementation. In summary, the current state of NOMA development shows great potential but faces challenges such as limited performance improvement and high bit error rates. The paper comes up with practical suggestions for optimizing NOMA to achieve mass 5G applications.