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孟乃宣 , 孙君 . 基于最佳虚拟网关的认知SCMA系统 [J ] . 电子学报 , 2021 , 49 ( 4 ): 736 - 743 . DOI: 10.12263/DZXB.20200165 http://doi.org/10.12263/DZXB.20200165 在5G的海量机器类通信（mMTC）场景下，为解决频谱资源不足和网络拥塞问题，本文提出一种基于最佳虚拟网关的认知SCMA系统模型.该模型根据QoS要求和地理位置把机器类通信设备（MTCD）分成独立的集群，在每个集群中通过认知无线电技术感知可能提供空闲频谱资源的LTE用户，定义为虚拟网关，再根据满意度最大规则选出最佳虚拟网关，将最佳虚拟网关提供的频谱资源分为多个子载波组，并设计MTCD与子载波组的最优匹配算法，MTCD以SCMA （稀疏码多址接入Sparse Code Multiple Access）方式接入网络.仿真结果表明所提方案可有效提高系统的吞吐量.

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赵耿 , 马艳艳 , 马英杰 . 基于混沌序列的SCMA码本设计及系统性能分析 [J ] . 通信学报 , 2019 , 40 ( 2 ): 137 - 144 . DOI: 10.11959/j.issn.1000-436x.2019026 http://doi.org/10.11959/j.issn.1000-436x.2019026 稀疏码多址接入（SCMA）技术是新一代5G通信技术的多址技术方案之一。针对5G海量用户传输需求问题，提出了用户传输信息时采用 logistic 混沌序列代替原始系统中的随机序列来选择码本。在编码端利用基于网格编码调制（TCM）的子集分割法设计星座图，结合映射矩阵生成码本，用户信息经信道传输后在解码端通过消息传递算法（MPA）进行解码。仿真结果表明，利用混沌的伪随机序列选择码字，系统传输的误码率（BER）较低，且在高过载率情况下系统性能表现良好。

ZHAO G , MA Y Y , MA Y J . Design of SCMA codebook based on chaotic signal and system performance analysis [J ] . Journal on Communications , 2019 , 40 ( 2 ): 137 - 144 . (in Chinese) DOI: 10.11959/j.issn.1000-436x.2019026 http://doi.org/10.11959/j.issn.1000-436x.2019026 Sparse code multiple access (SCMA) technology is one of the multiple access technology schemes for the new generation of 5G.In order to solve the transmission requirement of massive users,the logistic chaos sequence was proposed instead of the random sequence in the original system to select the codeword.The constellation method based on trellis coded modulation (TCM) subset segmentation with the mapping matrix was used to generate codebook in the encoder,and decoded through message passing algorithm (MPA) detection method.The simulation results show that the bit error rate (BER) is low when the system uses the pseudo-random sequence of chaos to select the codeword,and the system also performs well under the condition of high overload rate.

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