Abstract
Sparse code multiple access (SCMA) has emerged as a promising non-orthogonal multiple access technique for the next-generation wireless communication systems. Since the signal of multiple users is mapped to the same resources in SCMA, its detection imposes a higher complexity than that of the orthogonal schemes, where each resource slot is dedicated to a single user. In this paper, we propose a low-complexity receiver for SCMA systems based on the radical variational free energy framework. By exploiting the pairwise structure of the likelihood function, the Bethe approximation is utilized for estimating the data symbols. The complexity of the proposed algorithm only increases linearly with the number of users, which is much lower than that of the maximum a posteriori detector associated with exponentially increased complexity. Furthermore, the convergence of the proposed algorithm is analyzed, and its convergence conditions are derived. Simulation results demonstrate that the proposed receiver is capable of approaching the error probability performance of the conventional message-passing-based receiver.
Original language | English |
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Article number | 8509164 |
Pages (from-to) | 12398-12403 |
Number of pages | 6 |
Journal | IEEE Transactions on Vehicular Technology |
Volume | 67 |
Issue number | 12 |
Early online date | 25 Oct 2018 |
DOIs | |
Publication status | Published - Dec 2018 |
Externally published | Yes |
Bibliographical note
This work was supported in part by the National Science Foundation of China (NSFC) under Grants 61471037 and 61571041 and in part by the Foundation for the Author of National Excellent Doctoral Dissertation of China under Grant 201445. The work of Y. Li was supported in part by the Australian Research Council under Grant DP150104019 and in part by the NSFC under Grants 61531006 and 61772233. The work of L. Hanzo was supported by the Engineering and Physical Sciences Research Council through Projects EP/Noo4558/1 and EP/PO34284/1 of the Royal Society’s Global Challenges Research Fund as well as of the European Research Council’s Advanced Fellow Grant QuantCom.Keywords
- Bethe approximation
- convergence analysis
- Sparse code multiple access
- variational free energy