利用匹配傅里叶变换的直扩信号捕获算法  

Fast DSSS acquisition algorithm based on the match Fourier transform

作　　者：张轩 李勇朝[1] 叶迎晖 张海林[1] ZHANG Xuan LI Yongzhao YE Yinghui ZHANG Hailin(State Key Lab. of Integrated Service Networks, Xidian Univ. , Xi＇an 710071, China)

机构地区：[1]西安电子科技大学综合业务网理论及关键技术国家重点实验室,陕西西安710071

出　　处：《西安电子科技大学学报》2017年第5期18-24,113,共8页Journal of Xidian University

基　　金：高等学校学科创新引智计划("111计划")资助项目(B08038);先进轨道交通重点专项资助项目(2016YFB1200202)

摘　　要：针对临近空间超高速接收机在高动态环境下存在码片效应和多普勒效应,进而导致直扩信号能量累积受限的问题,提出一种基于粒子群快速离散匹配傅里叶变换的双块补零快速捕获算法.该算法在双块补零算法的基础上引入快速离散匹配傅里叶变换对码片效应和多普勒效应进行联合补偿,并通过粒子群算法进一步优化匹配傅里叶变换的迭代过程.仿真及理论分析表明,该算法能有效解决高动态所造成的累积增益损失,提升双块补零算法在低信噪比时的捕获概率和捕获精度且同时具有较低的运算量.当累积时间为10ms时,运算量为同类算法的46%.Induced by Chip Effects and Doppler Effects, the accumulating performance of the Direct Sequence Spread Spectrum signal is limited under high dynamic and low signal noise ratio scenarios in near space. To circumvent this problem, a particle swarm fast discrete match Fourier transform based Double Block Zero Padding algorithm is proposed by compensating Chip Effects and Doppler Effects simultaneously. Further, the particle swarm optimization is employed to optimize the iteration of fast discrete match Fourier transforms. Both simulation and theoretical analysis show that the proposed algorithm can not only enhance the acquisition probability and accuracy, but reduce the computational complexity as well. The computation of the proposed algorithm is 46~ that of other existing methods when the coherent time is 10 ms.

关 键 词：扩频通信 信号捕获 高动态 匹配傅里叶变换 粒子群优化 

分 类 号：TN914.42[电子电信—通信与信息系统]