A Low-Complexity Detection Algorithm for Uplink NOMA System Based on Gaussian Approximation

摘要

LDS-OFDM and SCMA are two examples of non orthogonal multiple access (NOMA), which is considered to be a promising technology for next generation wireless communications due to its larger capacity region compared with orthogonal multiple access (OMA). Iterative receiver structure is used in these two systems to get better performance than the noniterative receiver, but a direct implementation of iterative receiver with conventional message passing algorithm has a prohibitive computational complexity, especially when the system uses high order modulation. In this paper, Gaussian approximation is used to solve this problem, and can reduce the complexity of detector effectively. Simulation results demonstrate that the proposed Gaussian approximation based iterative receiver offers significant performance gains over the traditional non-iterative receiver structure. Even compared with the computationally intractable message passing based iterative receiver, the performance does not degrade much. This means that the proposed method offers a tradeoff between performance and complexity, and is a good candidate for future use in LDS-OFDM and SCMA systems.