高动态下基于DMF的伪码捕获频差估计研究  

Research on Frequency Offset Estimation of PN Code Acquisition Based on DMF under the Condition of High Dynamic

作　　者：张爱民[1] 国世超[1] 陈安乐[1] 韩方景[1] 

机构地区：[1]国防科技大学电子科学与工程学院,长沙410073

出　　处：《空间电子技术》2009年第4期12-15,共4页Space Electronic Technology

基　　金：航空科学基金项目(20060112005)

摘　　要：基于数字匹配滤波器(DMF)的PN码捕获电路具有较快的捕获速度,但其输出主相关峰值对频差较为敏感。为了消除频差对捕获性能的影响,文章提出了一种基于FFT的频差估计算法。首先构造一个载波频差的希尔波特复矢量,然后对其进行快速傅里叶变换。该算法能够精确检测出载波频偏的绝对值大小和方向,可以有效地改善大频差下的伪码捕获性能。The PN Code acquisition circuit based on DMF can accelerate the process of PN code acquisition. But the maximum correlation value is sensitive to frequency offset. In order to avoid influence of frequency offset on PN code acquisition, an algorithm based on FFT that can estimate frequency offset is presented, a hibert complex vector of carrier frequency offset must be constructed, and then Fast Fourier Transform, the algorithm can accurately estimate the absolute value and polarity of frequency offset. Therefore the research of this paper provide the solution for the better acquisition performance under the condition of frequency offset.

关 键 词：频差估计 复矢量 快速傅里叶变换 

分 类 号：TN914.3[电子电信—通信与信息系统] TN914.42[电子电信—信息与通信工程]