基于FFT的高动态直扩信号快捕改进方法研究  

Research on improved fast acquisition method based on FFT of high dynamic direct spread spectrum signal

作　　者：许斌[1] 崔永[2] 王传鑫[2] 李欣[2] 

机构地区：[1]装备指挥技术学院光电装备系,北京101416 [2]装备指挥技术学院研究生院,北京101416

出　　处：《国外电子测量技术》2009年第8期17-20,共4页Foreign Electronic Measurement Technology

摘　　要：本文针对大多普勒频偏条件下直扩信号捕获时间长的问题,分析了两种基于FFT算法的频偏精确估计改进方法。一是利用分段FFT的相位差修正算法,二是基于二次内插的频率FFT校正法。理论分析和MATLAB仿真结果表明,两种改进算法都能明显提高估计精度。最后指出在低信噪比环境下,二次内插法优于相位差修正法。Two kinds of improved code acquisition methods based on FFT are presented to solve the problems of long code acquisition time in high dynamic DSSS receivers having large frequency offset. One method is phase difference correction of partly FFT; the other is FFT frequency correction with quadratic interpolation. Both analysis and simulations demonstrate that two methods achieve high precision compared with traditional FFT. At last, the result indicates that FFT frequency correction with quadratic interpolation is better than phase difference correction of partly FFT on low SNR environment.

关 键 词：频偏估计 FFT 快捕 二次内插 相位差修正 

分 类 号：TP914[自动化与计算机技术]