摘要：最常见的非平稳信号就是线性调频信号，它使用范围广大，如地质勘探，生物医学，雷达通信等领域，尤其是在雷达领域，由于其低截获概率的特性，所以其信号是雷达信号的最佳选择，而处理线性调频信号时使用分数阶傅里叶变换是最佳的备选方式。本文利用MATLAB软件模拟对线性调频信号的处理，首先产生线性调频信号，然后利用分数阶傅里叶变换在其中的应用，实现了对线性调频信号的检测与估计，本文主要论述了分数阶傅里叶变换的主要原理算法。其次使用MATLAB软件仿真过程，实现了对信号主要参数的估计。由于分数阶傅里叶变换是一种一维的线性变换，可借助FFT实现，因此其在信号中的应用使得计算量大大减小，但并没有大幅度的降低检测与参数估计的精度。91652

毕业论文关键词：线性调频信号，分数阶傅里叶变换，系统仿真，MATLAB

Abstract:As the most usual non-stationary signal, the linear frequency modulation has been widely used in geological exploration, bio-medicine,radar, communication and so on, especially in the field of radar。 Due to its property of low probability of intercept, the signal is used as the best alternative of radar one, and the Fractional Fourier Transform is applied in the processing the linear frequency modulation signal。 In this paper, by using the MATLAB software simulation of linear frequency modulation signal, the processing of the first linear frequency modulation signal。 By using the process that MATLAB software simulation dealing with the linear frequency modulation signal, we firstly find the LFM in the using of the software, and then employing the Fractional Fourier Transform in the application and finally realize testing and estimation of the LFM。 This paper mainly discusses the main principle of Fractional Fourier Transform。 Besides the achievement above, the simulation process also makes the estimation of the main parameters of the signals。 Because the fractional Fourier transform is a kind of one dimensional linear transformation,it can be achieved by means of FFT, so its application in signal greatly reduces the amount of calculation, but it does not significantly reduce the accuracy of detection and parameter estimation。

Keywords:LFM ,FRFT ,system simulation ,MATLAB

目 录

1绪论 4

1。1引言 4

1。2课题研究背景及意义 5

1。3研究方法的发展状况 5

1。4本文的主要工作 5

2线性调频信号 6

2。1线性调频信号的定义 6

2。2线性调频信号的产生 7

2。3线性调频信号的处理方法 8

3线性调频信号的检测 9

3。1算法原理 9

3。2分数阶傅里叶变换信号检测的原理 10

3。3高斯白噪声下线性调频信号的分数阶傅里叶变换 11

4线性调频信号的估计 13

4。1采样原理 13

4。2线性调频信号的参数 13

5实验仿真 14

结论 17

参考文献 18

致谢 19

附录