文档介绍：摘 要
本论文利用混沌振子的初值敏感性和对噪声的免疫力检测微弱信号，分析了
Duffing 方程的基本形式以及 Duffing 振子的混沌运动，阐述了基于相平面变化进
行微弱信号检测的工作原理，并推导出系统发生间歇混沌现象的频差条件和相位差
对于系统特性的影响。文章给出了适合于检测微弱正弦信号、方波信号和任意周期
信号的仿真模型，随后利用此模型进行一系列仿真实验；提出改进的频率、相位、
幅值检测方法。最后，本文阐述了相关检测的原理以及将相关检测和混沌理论相结
合检测微弱正弦周期信号的新方法，同时给出了原理框图、试验模型和仿真试验结
果。
关键词：微弱信号检测，Duffing 振子，信噪比，间歇混沌，相关
ABSTRACT
The weak signal can be detected by chaotic oscillator owing to its property of
sensitive dependence on initial conditions and of immunity from noise. This paper
analyzes the basic form of Duffing equation and the chaotic motion of the Duffing
oscillator, and then describes the principle of weak signal detection based on the
change of phase trace. The frequency difference condition of the intermittent chaos
happening and the effect of phase difference on system performance are deduced.
The simulation model applicable to signal detection of sine wave，square wave and
arbitrary periodic signals is given. Afterwards, with these models, lots of simulation
experiments are done. Improved methods to detect frequency, phase and amplitude
are put forward. Finally, the principle of correlation detection and new methods for
weak signal detection based on combining correlation function with chaos theory
are introduced; simulation model, frame diagram and simulation results are given.
Liu Li(Communication and Information System)
Directed by prof Sun Jun
Key words: weak signal detection, Duffing oscillator, signal to noise ratio (SNR), intermittent chaos,
correlation
目 录
中文摘要
ABSTRACT
第一章 引言…………………………………………………1
本课题的选题意义……………………………………………1
本课题的研究现状……………………………………………3
本文的主要研究工作…………………………………………3
第二章 微弱信号检测的进展和混沌理论概述…………………5
微弱信号检测的常用方法………………………………………5
微弱信号检测的