基于全相位FFT的伪码捕获研究

摘要

To improve the acquisition performance of direct sequence spread spectrum (DSSS) system under a high dynamic telecommunication circumstance, a novel PN code acquisition system based on all-phase FFT (apFFT) is presented, the doppler frequences are parallel searched during the PN code phase searching time by the apFFT frequence chanels at the the same time, the all-phase time-shift phase difference method is introduced to correct the rough doppler frequence estimation, the first apFFT. Theoretical analysis and simulation results prove that compared with the traditional FFT PN code acquisition method, the proposed scheme, has a better Anti noise performanc, and is suit to the complex high dynamic communication environment.%为了快速捕获高动态直接序列扩频信号,文章基于全相位FFT(apFFT)设计了一种变换域伪码捕获方法,该方法利用apFFT的频率通道完成了对不同码相位上多普勒频偏的并行搜索,同时在apFFT的基础上,利用全相位时移相位差法进行频率校正,理论分析和仿真结果表明,相比于传统的FFT伪码捕获法,该方法在进行伪码搜索时,可完成对多普勒频高精度估计,并且该方法具有更强的抗噪性能,适用于存在强噪声且快速移动的复杂通信环境.