基于延时相乘结构的直扩载波最优检测  

Carrier detection of direct sequence spread signals based on a delay-and-multiply device

作　　者：石明军[1] 徐振平[2] 肖立民[1] 周世东[1] 姚彦[1] 

机构地区：[1]清华大学电子工程系,北京100084 [2]国防科技大学电子科学与工程学院,长沙410073

出　　处：《清华大学学报（自然科学版）》2009年第7期968-972,共5页Journal of Tsinghua University(Science and Technology)

基　　金：国家"九七三"重点基础研究项目(2007CB310608)

摘　　要：针对直接序列扩频信号在通信、导航和雷达等应用中具有低信噪比和低截获概率等特点,给信号侦察带来很大困难,提出了一种基于延时相乘结构的载波信号最佳检测方法。通过推导检测器的输出信噪比,研究了延时、带宽和输出信噪比的关系,得到了最优的参数设置方法。分析表明:在已知部分参数下,延时为零而且匹配滤波时检测器性能最佳;在未知参数条件下,当延时与带宽之积为0.4时,检测器性能达到最佳。在此基础上,分析了检测器的性能,并通过仿真实验验证了提出方法的有效性。Direct sequence spread spectrum signals are now widely used for communications, navigations systems and radar due to their low signal-to-noise ratios （SNR） and low probability of interception. However, spectrum surveillance of DSSS signals is difficult. Thus, a carrier detection method was developed based on delay-and-multiplication pre-filters. The relations between the delay, bandwidth and output SNR are used to idenfity the optimal system parameters. A theoretical analysis shows that with known partial parameters, the optimal detector is equivalent to the matched-filter energy detector with zero delay. With unknown parameters, the optimal bandwidth-delay product of the detector is 0.4. Simulations of the system performance with these settings verify the effectiveness of the method.

关 键 词：直接序列扩频 延时相乘 载波检测 

分 类 号：TN919[电子电信—通信与信息系统]