消除数据调制影响的FFT捕获方法

孙国良; 李育琦; 张晓林

消除数据调制影响的FFT捕获方法

北京航空航天大学电子信息工程学院, 北京 100083

详细信息

作者简介:
孙国良(1976-), 男, 山东潍坊人, 讲师, mrsgl@buaa.edu.cn.

中图分类号: TN 914.42
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- 被引次数: 0
出版历程
- 收稿日期: 2007-06-29
- 网络出版日期: 2008-03-31

FFT-based acquisition method to eliminate influence caused by data modulation

School of Electronics and Information Engineering, Beijing University of Aeronautics and Astronautics, Beijing 100083, China

摘要

摘要: 在利用快速傅里叶变换(FFT, Fast Fourier Transform)捕获扩频信号的过程中,为了提高捕获精度,会遇到基带数据调制影响捕获性能的问题.主要分析了基带数据符号跳变影响FFT捕获性能的原因:在频域内造成待检测信号的幅度衰减以及频点偏移.提出了一种解决此问题的方法:通过对I和Q两路信号的运算,构造一个不受数据调制影响的复信号,对此信号作FFT,完成捕获.给出了此方法的MATLAB仿真,以及基于现场可编程门阵列(FPGA, Field Programmable Gate Array)的实现方案.实验数据表明,此方法消除了基带数据调制对FFT捕获性能的影响,且在相等积分时间的条件下,比常用方法的捕获精度提高了一倍.
- 扩频通信 /
- 信号捕获 /
- 快速傅里叶变换 /
- 捕获精度 /
- 数据调制 /
- 现场可编程门阵列
Abstract: To achieve higher acquisition accuracy while using FFT(fast Fourier transform)-based algorithm to acquire spread spectrum signal, integration across data bit transition boundaries is necessary. However, performance degradation due to data modulation must be eliminated. Two effects of baseband data shift on acquisition performance, amplitude attenuation and frequency offset of the detected signal in frequency domain, were analyzed. A method to solve this problem was given. This algorithm constructs a complex signal which is free from data modulation, and detects Doppler shift using this signal through FFT. Simulation in MATLAB and FPGA(field programmable gate array)-based implementation of this method was also described. The simulation and experiment results verify that, this method can overcome the problem caused by baseband data shift, and improve acquisition accuracy by one times compared with conventional method in the same predetection integration time.
- spread spectrum communication /
- signal acquisition /
- fast Fourier transform /
- acquisition accuracy /
- data modulation /
- field programmable gate array

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参考文献(1)

[1] Holmes J K, Chen C C. Acquisition time performance of PN spread-spectrum systems[J]. IEEE Transactions on Communication,1977,25(8):778-784 [2] Chawla K K, Sarwate D V. Parallel acquisition of PN sequences in DS/SS systems[J]. IEEE Transactions on Communication,1994,42(5):2155-2164 [3] 朱昆,黄启华,郑玉簋. FFT在高动态扩频信号快速捕获中的应用张洪涛.北京航空航天大学第三届研究生学术论坛论文集.北京:北京航空航天大学研究生院,2006:120-125 Zhu Kun,Huang Qihua, Zheng YuGui. Implementation and analysis of an FFT approach for fast spread spectrum code acquisition in dynamic circumstance Zhang Hongtao. The Attendance Guide of 3rd Academic Forum for Graduate Students at Beihang University.Beijing: Graduate School,Beijing University of Aeronautics and Astronautics,2006:120-125(in Chinese) [4] Tsui James Bao-Yen. Fundamentals of global positioning system receiver: a software approach [M]. New York:John Wiley & Sons Inc,2000:137-138 [5] 郭肃丽,刘云飞.一种基于FFT的伪码快捕方法[J].无线电通信技术,2003,29(1):11-13 Guo Suli, Liu Yunfei. An FFT-based approach for the fast acquisition of PN Code[J].Radio Communication Reference,2003,29(1):11-13(in Chinese) [6] 胡建波,杨莘元,卢满宏.一种基于FFT的高动态扩频信号的快捕方法[J].遥控遥测,2004,25(6):19-24 Hu Jianbo, Yang Xinyuan, Lu Manhong. An FFT based method for fast acquisition of high dynamic DS spread spectrum signals[J]. Telemetry and Telecontrol, 2004,25(6):19-24(in Chinese)

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