Resource-Selection Based Low Complexity Detector for Uplink SCMA Systems With Multiple Antennas

Abstract

Sparse code multiple access (SCMA) is a novel non-orthogonal multiple access scheme for 5G systems, in which based stations are usually equipped with multiple antennas. In this letter, we propose a novel resource-selection based message passing algorithm (RSB-MPA) detector for uplink SCMA systems with multiple receive antennas. In the proposed RSB-MPA detector, several resources are selected to perform the Jointly Gaussian Algorithm and the remaining are to perform the maximum likelihood algorithm. The resource selection criterion is based on the minimum distance at each resource, which is lower bounded by the minimum singular value of the corresponding channel matrix. Simulation results show that the RSB-MPA detector can significantly reduce the computational complexity with slight performance degradation.