一种低复杂度SCMA多用户检测算法

doi:10.19665/j.issn1001-2400.2019.04.012

摘要/Abstract

摘要：

为了进一步降低稀疏码多址接入系统中多用户检测算法的复杂度,提出了一种基于部分资源块高斯近似的多用户检测算法。首先对资源块优势等级进行比较;然后选择译码优势等级高的 $n$ 个资源块使用加权消息传递算法,剩下的资源块使用高斯近似消息传递算法。同时联合资源块和用户优势等级,在每次迭代后对译码优势等级较高的用户直接译码并剔除,使得后续每轮迭代的复杂度依次降低。仿真结果表明,通过合理选择资源块个数,可以在保证检测性能的同时,有效地降低检测复杂度。因此,提出的算法较好地实现了译码性能和复杂度之间的平衡。

关键词: 稀疏码多址接入, 消息传递算法, 资源块, 高斯近似

Abstract:

To further reduce the complexity of multi-user detection algorithm for a sparse code multiple access system, a multi-user detection algorithm applied Gaussian approximation based on partially resource nodes is proposed. We first compare the superiority levels of resource nodes, then selectresource nodes with higher superiority and apply the weighted message passing algorithm to those nodes. For the remaining resource nodes, the Gaussian approximation is performed. Meanwhile, we develop a method for combining the superiority levels of resource nodes and users, and directly decode and remove the users with a higher superiority level after each iteration, so the complexity of subsequent iteration is decreased gradually. Simulation results show that, by rationally selecting the resource nodes, the proposed algorithm can guarantee the detection performance and effectively reduce the detection complexity, thus achieving a better tradeoff between the decoding performance and complexity.

Key words: sparse code multiple access, message passing algorithm, resource nodes, Gaussian approximation

中图分类号:

TN929.5

朱翠涛,吴蓓. 一种低复杂度SCMA多用户检测算法[J]. 西安电子科技大学学报, 2019, 46(4): 80-86.

ZHU Cuitao,WU Bei. Low-complexity multi-user detection algorithm for an SCMA system[J]. Journal of Xidian University, 2019, 46(4): 80-86.

图/表 8

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表1

复杂度比较"

迭代次数	消息传递算法 (MPA)	PGA-MPA (1≤n<K)
第1次迭代	K $M d R$	O¹=n $M d R$ +(K-n)M
第2次迭代	K $M d R$	n $M d R - 1$ +(K-n)M<O²<O¹
第3次迭代	K $M d R$	n $M d R - 2$ +(K-n)M<O³<O²
第t次迭代	K $M d R$	n $M d R - (t - 1)$ +(K-n)M<O^t<O^t^-1

表1

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图7

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