摘要
由多维星座经星座运算得到用户码本的典型稀疏码多址接入(SCMA)码本设计方案中,多维星座设计的复杂度和最优星座运算确定的难度实际上增加了码本设计难度,对此,分析了SCMA码本对消息传递算法(MPA)具体过程的影响,提出了一种以最大化距离谱最小元素为准则的SCMA码本设计方案.所提方案将多维星座的设计和星座运算的确定过程转化为简单的码本设计参数选择过程.在不影响用户码本唯一可译码性的前提下,通过替换部分码本设计参数,降低了参数选择复杂度.仿真结果表明,采用所提基于距离谱的码本设计方案与现有的码本设计方案相比,系统的误比特率性能有显著改善.
Aiming at the problem that the complexity of multidimensional constellation design,and the difficulty of determining optimal constellation operators actually increase the difficulty of codebook design in the typical sparse code multiple access(SCMA)codebook design scheme,which gets user codebooks from a multidimensional constellation via the constellation operation,the influence of user codebooks on the specific process of message passing algorithm(MPA)is analyzed,and a codebook design scheme based on maximizing the minimum element of the distance spectrum is proposed.The scheme transforms the process of multidimensional constellation design,and constellation operators determination into a simple codebook design parameter selection process.Without affecting the unique decodability of user codebooks,the complexity of parameter selection is reduced by replacing some codebook design parameters.Simulations show that compared with the existing SCMA codebook design schemes,the scheme based on distance spectrum can significantly improve the bit error rate performance of system.
作者
郭鸣坤
邵小桃
杨维
GUO Ming-kun;SHAO Xiao-tao;YANG Wei(School of Electronic and Information Engineering,Beijing Jiaotong University,Beijing 100044,China)
出处
《北京邮电大学学报》
EI
CAS
CSCD
北大核心
2019年第3期1-6,28,共7页
Journal of Beijing University of Posts and Telecommunications
基金
国家重点研发计划项目(2016YFC0801800)
国家自然科学基金项目(51474015)
关键词
稀疏码多址接入
码本设计
消息传递算法
距离谱
sparse code multiple access
codebook design
message passing algorithm
distance spectrum
