摘要
为解决低信噪比下长伪码序列快速捕获问题,提出一种基于迭代消息传递算法的快速捕获方法.通过证明m序列是一种特殊的线性分组码,将m序列用Tanner型因子图表示,然后在得到的图模型上迭代运行消息传递算法来估计m序列的初始相位.在低信噪比下的分析和仿真结果均表明:该算法能稳定工作.相比混合捕获算法,其检测性能下降了大约5 dB,但其平均捕获时间约为同条件下混合捕获方法的1/10,其计算复杂度仅为传统捕获算法的几十分之一.
A rapid acquisition based on iterative message passing algorithm （iMPA） was developed to solve the problem of rapid acquisition for a long pseudorandom （PN） code under low SNR. Tanners＇ factor graph was u^d to represent the m sequence via demonstrating that m sequence is a sort of especial linear block code, and then the message passing algorithm was executed iter- atively to estimate the original phase of the received m sequence over the graph model. Both analysis and simulation results show that the rapid acquisition using iMPA can work steadily under low SNR, and its detection performance drops about 5 dB com- paring with hybrid acquisition. But the average acquisition time is about one tenth of the hybrid acquisition in the same acquisi- tion environment, and the computing complexity is only one over tens of the traditional acquisition.
出处
《大连海事大学学报》
CAS
CSCD
北大核心
2009年第1期43-46,52,共5页
Journal of Dalian Maritime University
基金
国家自然科学基金资助项目(60704018)
关键词
长伪码序列
快速捕获
迭代消息传递算法(iMPA)
因子图
long pseudorandom （ PN ） code
rapid acquisition
iterative message passing algorithm （iMPA）
factor graph
