窄带脉冲干扰环境下直扩信号伪码周期及序列的盲估计  

Blind Estimation for the Pseudo-code Sequence and Its Period of DSSS Signals Under Narrowband Impulse Interference Environment

作　　者：王绍威 高勇[1] 

机构地区：[1]四川大学电子信息学院,成都610065

出　　处：《电子信息对抗技术》2015年第4期8-14,共7页Electronic Information Warfare Technology

摘　　要：带内窄带脉冲干扰会对直接序列扩频信号估计性能产生较大的影响,针对此问题,提出了一种抑制窄带脉冲干扰并对扩频码序列及周期的盲估计算法。采用最大熵概率密度谱估计算法估计出接收信号的概率密度谱,进而用估计的概率密度谱设计滤波函数对信号滤波来抑制窄带脉冲干扰。利用二次谱算法对扩频码周期进行估计并通过Viterbi算法对扩频序列进行提取。仿真实验表明,该算法不仅能抑制较强的窄带脉冲干扰,而且能在无先验信息的条件下估计出扩频信号的扩频码周期及序列等信息,从而获知直扩通信中所传输的码元序列。Aiming at the issue of blind estimation of direct sequence spread spectrum （DSSS） signals in narrowband impulse interference environment, an algorithm of blind estimation for spreading code and its period after suppressing narrowband impulse interference is proposed. A maximum entropy probability density function （PDF） estimation algorithm is used to estimate the PDF of received signal. Then the estimated PDF is utilized as parameter of the filter, whose function is suppressing the narrowband impulse interference in received signal. Spectrum repro-cessing is performed to estimate the period of spreading code and the sequence of spreading code could be estimated by Viterbi algorithm. Simulation results show that this algorithm performs well in suppressing narrowband impulse interference in strong narrowband noise environment, al-so in estimating the spreading code and its period without any priori information, and then the chip sequence of DSSS communication is obtained.

关 键 词：窄带脉冲干扰抑制 直扩信号 二次谱 VITERBI 算法 盲估计 

分 类 号：TN973[电子电信—信号与信息处理]