一种基于循环谱的直扩信号参数估计方法

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一种基于循环谱的直扩信号参数估计方法

作者：曹志明张继文

来源：《现代电子技术》2010年第07期

摘要:分析BPSK调制的直扩信号循环谱密度函数特征,提出一种直扩信号参数估计方法。从循环谱物理意义入手,计算谱密度,通过时域预处理,可以减少DFT要求的数据量,提高运算效率,使循环谱实时处理成为可能,同时可以准确分辨出循环频率方向和谱频率方向的谱峰;在非零循环频率上搜索特征谱线,可以在较低信噪比环境下完成直扩信号载波频率和PN码速率的估计,并通过仿真确定了该方法的信噪比容限。

关键词:循环平稳; 循环频率; 参数估计; 直扩信号

中图分类号:TN911 文献标识码:A

文章编号:1004-373X(2010)07-0085-04

Method of Direct Sequence Spread Spectrum Signal Parameter Estimation

Based on Cyclostationary Spectral Density

CAO Zhi-ming, ZHANG Ji-wen

(Patent Examination Cooperation Center of SIPO, Beijing 100190, China)

Abstract: The function characteristics of the spectral correlation density of the direct sequence spread spctrum signal modulated by BPSK are analysed, and a new method for parameter estimation of the direct sequence spread spctrum signal is proposed. The cyclic spectral density is calculated proceeding with the cyclic spectrum physical meaning, and the burden of calculation is lessened greatly by the time domain preprocessing. It reduces the quantity of data required by DFT, improves computational efficiency, and improves the capability for the real-time processing in cyclic spectral estimation. Moreover, the spectrum peaks can be identified clearly both in cyclic frequency direction and spectrum frequency direction. This algorithm makes use of the positions and magnitude of non-zero cyclic spectral peaks to estimate the key parameters in low SNR environment. The result of the simulation proves the validity of the algorithm.

Keywords:cyclostationariness; cyclic frequency; parameter estimation; direct sequence spread spectrum signal