内容发布更新时间 : 2024/5/20 18:54:00星期一 下面是文章的全部内容请认真阅读。

摘 要

线性调频信号即LFM信号是一种在雷达，通信，声纳，地震探测等领域中有着重要作用的非平稳信号。因为LFM信号是一种非平稳信号，对它进行参数估计会比较复杂，现在的处理方法大多是使用时频面上的二维峰值搜索。分数阶傅里叶变换是时频变换中的一种，因为它在处理多分量LFM信号时不会产生交叉项，所以在LFM信号的参数估计中得到了广泛的应用。

本文首先介绍了分数阶傅里叶变换的基本定义及性质，然后介绍了变换的离散算法中的采样型算法，即Ozaktas采样型算法和Pei采样型算法，并使用这两种算法在matlab上进行了LFM信号参数估计的仿真实验。

在论文的安排上，首先介绍了题目的背景和所做的工作；然后，介绍了离散分数阶傅里叶变换的定义及计算过程，还有使用这些算法进行参数估计时的计算方法；之后，讲述了的仿真过程和结果；最后，对实验结果进行了分析和主观评估。

关键词：分数阶傅里叶变换；线性调频信号；参数估计；离散算法

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Abstract

The LFM signal is a kind of non-stationary signal ,which plays an important role in the field of radar, communication, sonar, seismic detection etc.Because of LFM signal is a nonstationary signal, so the parameter estimation for it is more complex. now most of the method to estimation it parameter,is two-dimensional peak search on ime-frequency plane .Fractional Fourier transform is one kind of frequency conversion, because when it's processing the multi-component LFM signal it will not get cross terms. so it has been widely used in the parameter estimation of LFM signal .

This article first introduces tthen introduces the discrete fractional Fourier transform algorithm type of sampling algorithm, and use these two kinds of algorithm do parameter estimation of LFM signal simulation experiment on matlab.

On the arrangement of the thesis, the author firstly introduces the background of the topic and the authors have done;Then, this paper introduces the definition of discrete fractional Fourier transform and the calculation process, and using these algorithms for parameter estimation method;After, tells the way of the process and results of the author;Finally, the experimental results are analyzed and subjective evaluation.

Keywords: FRFT；LFM signal；parameter estimation；disperse calculate

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目录

第1章 引 言 ....................................................................................................................... 1 1.1 应用背景及其意义 ....................................................................................................... 1 1.2 研究的现状 ................................................................................................................ 2 第2章 离散分数阶傅里叶变换 ........................................................................................ 7 2.1 分数阶傅里叶变换 .................................................................................................... 7 2.1.1 分数阶傅里叶变换的定义 ................................................................................. 7 2.1.2 分数阶傅里叶变换的性质 ................................................................................. 9 2.2 离散分数阶傅里叶变换 .......................................................................................... 11 2.2.1 离散分数阶傅里叶变换简介 ........................................................................... 11 2.2.2 Ozaktas采样型算法 .......................................................................................... 12 2.2.3 Pei采样型算法 .................................................................................................. 16 2.3 基于FRFT的LFM信号参数估计的理论模型 .................................................... 18 2.3.1 基于Ozaktas算法的参数估计模型 ................................................................ 19 2.3.2 基于Pei算法的参数估计模型 ........................................................................ 21 第三章 基于DFRFT的LFM信号参数估计 ................................................................ 22 3.1 引言 .......................................................................................................................... 22 3.1.1主要技术和方法 ................................................................................................ 22 3.1.2问题总结与分析 ................................................................................................ 23 3.2 算法设计及实验分析 .............................................................................................. 24 3.2.1 使用FFT来对LFM信号进行参数估计 ........................................................ 24 3.2.2 基于Ozaktas算法的参数估计 ........................................................................ 27 3.2.3 基于Pei算法的参数估计 ................................................................................ 31 第4章 对实验结果的分析 .............................................................................................. 39 4.1两种算法对参数估计的实验结果分析 ................................................................... 39

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