| 引用本文： |
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郭道省,郭文韬,秦 勇,等.低信噪比高动态条件下基于FFT的二维平移累加PN码捕获算法[J].电讯技术，2012，52（3）： - . [点击复制]
- GUO Dao-xing,GUO Wen-tao,QIN Yong,et al.Two-dimensional shift accumulation algorithm based on FFT for PN code acquisition in high dynamic and low SNR environment[J].，2012，52（3）： - . [点击复制]
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| 摘要: |
| 针对低信噪比高动态条件下直接序列扩频（DSSS）系统中PN码捕获的问题，提出了基于FFT
二维平移累
加的PN码捕获算法。首先对现有的PN码捕获技术进行了分析，然后研究了时变的载波频偏与
码频频偏对PN码捕获的影响，在此基础上，提出了基于FFT二维平移累加的PN码捕获算法。
算法的基本思想是对相关器输出的相关值在载波频偏不确定度与码相位不确定度同时进行平
移，从而消除相关峰“漂移”现象，增大非相干累加的有效性。给出了采用此算法的捕获系
统结构图，并对关键参数进行了分析。最后，通过仿真表明了该算法对捕获系统有6 dB的改
善。 |
| 关键词: 直接序列扩频 低信噪比 高动态 PN码捕获 载波频偏 码频
频 |
| DOI： |
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| 基金项目: |
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| Two-dimensional shift accumulation algorithm based on FFT for PN code acquisition in high dynamic and low SNR environment |
| GUO Dao-xing,GUO Wen-tao,QIN Yong,XU Li,YANG Mao-qiang |
| () |
| Abstract: |
| This paper provides twodimensional shift accumulation algorithm based on
FFT for acquisition of high dynamic DSSS(Direct Sequence Spread Spectrum) signal
with low signaltonoise ratio(SNR).
Firstly, current PN code acquisition technologies are analysed. Secondly, PN co
de acquisition affected by changing carrier frequency offset and code frequency
offset is researched. On this base, twodimensional shift accumulation alg
orithm based on FFT for acquisition of PN code is provided, and the fundamental
ide
a of the algorithm is that correlation results from correlators will be shifted
simultaneously in carrier frequency offset and code phase uncertainty region, an
d this can eliminate the phenomenon of correlation peaks drift and makes non-
coherent accumulation more effective. Structure diagram and working principle of
acquisition system which uses this algorithm are given, and choice for importan
t
parameters is analysed. Simulation shows that performance of acquisition system
is impr
oved by 6 dB with this algorithm. |
| Key words: low signal-to-noise ratio high dynamic PN code acquisition carrier frequency o
ffset code frequency offset |
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