Software Defined Radio Based Non-orthogonal Multiple Access (NOMA) Systems

This paper focuses primarily on the study of the implementation of Non-orthogonal multiple access (NOMA) systems on Software defined radio (SDR) platforms, since NOMA has been recognized as a key enabling technology for the fifth generation (5G) wireless networks. A comprehensive review of the original birth, the latest trends, and the future research directions of NOMA is given in this paper. Specifically, several Successive Interference Cancellation (SIC) receivers are provided with mathematical analysis, such as the Ideal SIC receiver, Symbol-level SIC receiver, Codeword-level SIC receiver and Log likelihood ratio (LLR) based receivers. Furthermore, the bit error rate of two users' signals is analyzed by implementing the NOMA system with and without the SIC using GNU Radio software. In addition, the performance of orthogonal multiple access (OMA) and NOMA systems is compared in terms of rate pairs (throughput), spectral efficiency and energy efficiency. Finally, the results reveal that the NOMA system performs better than OMA systems and it will be highlighted that SDR is a flexible platform to implement and test future wireless technologies.