基于信噪比的自适应门限判决PN码捕获算法  

Adaptive Threshold Decision PN Code Acquisition Algorithm Based on SNR

作　　者：尚耀波[1,2] 郭英[1] 王锦江[2] 韩立峰[1,2] 

机构地区：[1]空军工程大学信息与导航学院,西安710077 [2]空军工程大学综合电子信息系统与电子对抗技术研究中心,西安710051

出　　处：《南京邮电大学学报（自然科学版）》2014年第4期88-93,共6页Journal of Nanjing University of Posts and Telecommunications：Natural Science Edition

基　　金：国家部委基金(51310020401);陕西省电子信息系统综合集成重点实验室基金(2011ZD09)资助项目

摘　　要：现有的自适应门限判决PN码捕获方法在低信噪比条件下的检测概率较低。针对这一问题,文中提出一种考虑噪声功率的改进算法。该算法首先通过参数设置对基于信噪比的门限进行调整,然后利用中值滤波平滑门限波形,减少了由于起伏波动引起的错误捕获,最后通过限幅滤波降低因毛刺造成的虚警概率。理论分析以及蒙特卡罗仿真表明,改进算法较现有算法能够获得更高的检测概率和更低的虚警概率,同时对窄带干扰有较强的抑制能力。The present adaptive threshold based PN code acquisition methods can only obtain low detection probability under the condition of low SNR.To resolve this problem,an improved algorithm based on noise power is proposed.Firstly,the threshold based on the SNR is adjusted by parameter setting.Secondly,the median filter is brought to smooth the threshold waveform,this makes the fluctuations caused by the error trapping reduced.Finally,the limiting filter is used to reduce the false alarm probability caused by glitches.The theoretical analysis and Monte Carlo simulations show that the proposed method can obtain higher detection probability,lower false alarm probability and strong narrowband interference rejection capability compared with the original algorithms.

关 键 词：自适应门限 信号检测 虚警概率 捕获 

分 类 号：TN911.3[电子电信—通信与信息系统]