Fractional Fourier Transform Of The Lfm Signal Detection Theory And Application

In practical application , the signals , such as radar signal , seismic wave and sonar signal etc. , these are nonstationary signal .Traditionally Fourier analysis is a transform in full-time domain , it can't describe the signal property in time-frequency domain , but this is the most important and key property of a nonstationary signal . so some people study and advance a series of new signal analysis theories , such as short Fourier transform , time-frequency analysis , Gabor transform , wavelet transform , Radon-Wigner transform , Fractional Fourier transform and so on . Fractional Fourier transform is found on the rotate of coordinate axis , it is an one dimension linearity transform essentially , can't describe the local properties of signal in time domain or frequency domain .but if use the fractional transform axis u ,v make a (u ,v)plane to describe the signal , Fractional Fourier transform can be used to analysis signals in time-frequency plane , and because it's a linearity transform , it can wipe off the across item in twain transform .In this thesis , the main aim is to study the method for intercepting and processing one of nonstationary signal~LFM signal , the following aspects has researched in this thesis , and obtained some valuable results :Found the model for separation filter and interference using Fractional Fourier transform.Bring forward a method for estimating the frequency in radar signal detection .Found the model of antenna array , bring forward an algorithm to estimate the 2D DOA base on TLS-ESPRIT algorithm and MUSIC algorithm.Bring forward a algorithm to estimate DOA under the spatial sub-Nyqusit sampling.Bring forward a algorithm to estimate frequency under the temporal sub-Nyqusit sampling.