SCMA Detection in MIMO Systems with Low Complexity EP using QRD

This article presents new low complexity message passing based detection algorithms for Sparse Code Multiple Access (SCMA) in Multiple Input Multiple Output (MIMO) systems thanks to the combination of sparser Factor Graph (FG) representation via QR Decomposition (QRD) and enhanced message-passing scheduling. The proposed algorithm achieves better performance to complexity trade-off than state-of-the-art message-passing-based detectors. Our results are presented based on complexity and error rate performance analysis.