PN序列估计与扩频隐藏信息分析

摘要

An efficient method that can estimate PN sequence of direct sequence spread spectrum (DS-SS) signal is presonted in a non-cooperative comext, on this base, spread-spectrum hidden message can be extracted blindly. At first, the optimization model with the cumnulative correlation value between estimate sequence and SS signal as the objective function is established, and then the PN sequeace can be estimated by Genetic Algorithm. Finally, by analyzing the correlation between PN sequence and stegosignal,the hidden messmate can be extracted.The method bas been carried out on PC, the experimental results show that,PN sequence estimation peformance of the low-SNR DS-SS signal is good,nnd the extracted hidden message can be identificated.%在非协作信息侦测情况下,提出了一种直接序列扩频(DS-SS)信号PN序列的估计方法,在此基础上实现了扩频隐藏信息的盲提取.该方法以估计序列和扩频信号的累积相关值为目标函数,建立估计序列长度及其构成的两变量优化模型,通过遗传算法求解,可较好地估计出PN序列.通过获取的PN序列与藏密信号的相关性分析,可实现扩频隐藏信息的盲提取.该方法已在微机上进行了实验,实验结果表明,该方法在截获信号信噪比较低情况下仍具有较好的估计性能,提取的秘密信息具有较好的可辨认性.