一种混沌扩频信号的同步方法及仿真  

Algorithm and Simulation for Fast Acquisition of Chaotic Sequence in Spectrum-Spread System

作　　者：朱文明[1] 程剑[1] 李广侠[1] 李志强[1] 

机构地区：[1]解放军理工大学通信工程学院全军卫星通信重点试验室,南京210007

出　　处：《系统仿真学报》2011年第1期100-103,共4页Journal of System Simulation

基　　金：国家863计划项目(2008AA12A204);国家自然科学基金(60972061;60972062;61032004)

摘　　要：提出了一种低信噪比条件下混沌扩频信号的捕获算法,利用扩频序列在时间上的相关等价于频域内相乘的特性,可实现无周期混沌扩频信号的快速捕获,并对频差搜索方法做了改进,给出降低捕获门限的方法,提出了捕获时消除数据调制的方法。然后,运用Matlab 6.0仿真分析了这种同步方法在各种条件下,特别是低信噪比条件下的捕获性能。仿真结果表明此方法捕获时不需要数据辅助并可以使捕获时间大幅度缩短,该方法能够实现低信噪比条件下混沌扩频信号的快速捕获。An algorithm for acquisition of the chaotic sequence in spectrum-spread system under low SNR condition was proposed based on the principle that the correlation of signals in time domain was equivalent to the multiple product in frequency domain, and the fast acquisition for non-periodical chaotic sequence could be realized. An improve method for scanning the frequency offset was proposed, and a method to decrease the acquisition threshold was also proposed, and a method to remove data modulation during acquisition process was demonstrated. Matlab 6.0 software was used to simulate the acquisition performance of this synchronization method under all conditions, especially under the low SNR conditions. Simulation results prove such method can realize the fast acquisition for chaotic sequence under the low SNR conditions.

关 键 词：混沌序列 扩频 频域变换 仿真分析 

分 类 号：TN929.5[电子电信—通信与信息系统]