On Gaussian Approximation Algorithms for SCMA

Sparse code multiple access (SCMA) is a promising technique in future fifth generation (5G) wireless networks. Since message passing algorithm (MPA) as a widely-used SCMA detection algorithm has exponential complexity with codebook size, researching lower complexity algorithms is of significant importance. In this paper, we propose a first-order approximated algorithm based on Gaussian approximation (FO-GAA). Simulation results demonstrate that FO-GAA is an excellent alternative algorithm among simplified detection algorithms with high convergence rate, lowest complexity and good BER performance.