JOURNAL OF CHINA UNIVERSITIES OF POSTS AND TELECOM ›› 2017, Vol. 24 ›› Issue (1): 11-17.doi: 10.1016/S1005-8885(17)60182-1

• Wireless • Previous Articles     Next Articles

Optimized multiuser detection algorithm for uplink SCMA system

Tan Yuxi, Gao Zehua, Guo Siyan, Gao Feng   

  1. School of Information and Communication Engineering, Beijing University of Posts and Telecommunications
  • Received:2016-11-11 Revised:2017-01-17 Online:2017-02-28 Published:2017-02-28
  • Contact: Yu-Xi TAN E-mail:tanyuxi@bupt.edu.cn
  • Supported by:
    This work was supported by the NSFC Young Scientists Research Fund (61501047).

Abstract: Sparse code multiple access (SCMA) is a competitive nonorthogonal access scheme for the next mobile communication. As a multiuser sharing system, SCMA adopts message passing algorithm (MPA) for decoding scheme in receiver, but its iterative method leads to high computational complexity. Therefore, a serial message passing algorithm based on variable node (VMPA) is proposed in this paper. Making some subtle alterations to message update in original MPA, VMPA can greatly reduce overall computing complexity of decoding scheme. Furthermore, considering that serial structure may increase decoding delay, a novel grouping scheme based sparse matrix is applied to VMPA. Simulation results verify that the new algorithm, termed as grouping VMPA (G-VMPA), can achieve a better tradeoff between bit error rate (BER) and computing complexity than MPA.

Key words: SCMA, MPA, computational complexity

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