基于LFM模型的高动态弱GPS信号载波捕获  

Carrier Acquisition of High Dynamic and Weak GPS Signal Based on LFM Model

作　　者：何晓云 冯冀宁[2] 杨晓波[3] 

机构地区：[1]北京卫星导航中心,北京100094 [2]河北师范大学电子工程系,石家庄050031 [3]石家庄职业技术学院电子工程系,石家庄050081

出　　处：《电讯技术》2015年第8期895-900,共6页Telecommunication Engineering

摘　　要：根据极大似然估计理论,通过载波频率和频率变化率分段对消、快速傅里叶变换(FFT)结果选大估计载波频率和频率变化率,实现载波信号捕获,建立了高动态全球定位系统(GPS)载波的线性调频(LFM)信号模型,并给出了算法的具体实现。详细分析了该算法中检测统计量的分布特性,推导了恒虚警准则下的检测门限,并讨论了其中关键参数的设计。仿真结果表明,该算法可以实现对18 d BHz的GPS高动态信号的载波捕获。According to the maximum likelihood （ML） method, through the correlation cancellation of carri- er frequency and carrier frequency change selecting maximum value of fast Fourier transform （ FFT）, carrier acquisition is realized and a linear frequency modulation （LFM） signal model of high dynamic global posi- tioning system（GPS） carrier is established. The implementation solution of the algorithm is presented in which the distributing characteristic of detecting statistic quantity is analyzed, the detecting threshold under the constant false alarm rules is derived and the key parameters design is presented. The simulation results show that the algorithm can achieve the carrier acquisition of high dynamic GPS signals in 18 dBHz.

关 键 词：GPS 载波捕获 高动态 微弱信号 线性调频 

分 类 号：TN962[电子电信—信号与信息处理]