發(fā)布時間：2018-06-23 16:15

  本文選題：線性調(diào)頻連續(xù)波雷達 + 距離速度去耦合��； 參考：《西安電子科技大學(xué)》2014年碩士論文

【摘要】：線性調(diào)頻連續(xù)波(LFMCW)雷達通過對連續(xù)波進行頻率調(diào)制來獲取被測目標距離與速度信息。由于其具有無測距盲區(qū)、測距測速精度高、發(fā)射信號時寬帶寬積大、接收靈敏度高、結(jié)構(gòu)簡單等優(yōu)點,得到了國內(nèi)外學(xué)者的重視,LFMCW雷達的理論研究、關(guān)鍵技術(shù)及其應(yīng)用得到了迅速發(fā)展。其中,運動目標距離速度去耦合方法以及強目標背景下的弱小目標檢測算法是LFMCW雷達信號處理的重要研究方向,也是本文研究的重點。本文首先研究了一種傳統(tǒng)的基于差拍傅里葉-頻域配對法的LFMCW雷達信號處理算法。由于LFMCW雷達在發(fā)射單一調(diào)頻斜率的連續(xù)波時被測動目標差拍信號頻率會出現(xiàn)偏移,導(dǎo)致無法獲取準確的目標信息。因此該方法中雷達發(fā)射信號采用三角波形調(diào)制連續(xù)波,根據(jù)運動目標差拍頻率在對稱三角形調(diào)頻連續(xù)波正、負斜率頻段會出現(xiàn)對稱偏移的特點,采用差拍傅里葉-頻域配對法對目標回波進行處理,將同一個目標在正、負斜率掃頻段的兩個頻譜進行配對,消除運動目標多普勒頻率的影響,得到被測目標的真實距離與速度。該方法的優(yōu)點是結(jié)構(gòu)簡單,易于實現(xiàn),但在檢測具有大動態(tài)范圍的多目標差拍信號時,容易出現(xiàn)弱小目標無法被檢測的情況。鑒于差拍傅里葉-頻域配對法存在的問題,本文提出了一種基于信道化結(jié)構(gòu)的LFMCW雷達信號處理新方法。該方法采用信道化結(jié)構(gòu)替代傳統(tǒng)的差拍傅里葉方法,對不同目標差拍信號頻率進行檢測后完成配對,實現(xiàn)動目標的距離速度去耦合。針對差拍傅里葉方法在檢測大動態(tài)范圍的多目標差拍信號時出現(xiàn)丟失弱小目標的問題,本文設(shè)計了高阻帶衰減的原型濾波器,利用信道化結(jié)構(gòu)完成強目標背景下弱小目標的檢測。文中最后利用MATLAB仿真驗證了基于信道化結(jié)構(gòu)LFMCW雷達信號處理方法的有效性,并與傳統(tǒng)的基于差拍傅里葉結(jié)構(gòu)方法在檢測弱小目標問題上進行了對比,仿真結(jié)果表明在多目標環(huán)境下,本文提出的方法可以準確測出各目標的距離、速度。當(dāng)原型低通濾波器阻帶衰減滿足要求時,該方法可以用于弱小目標的檢測,并達到較好的效果。
[Abstract]:The linear frequency modulated continuous wave (LFMCW) radar can obtain the range and velocity information of the target by frequency modulation of the continuous wave. Because of its advantages such as no blind area of ranging, high accuracy of ranging and velocity measurement, large wide band product when transmitting signal, high sensitivity of receiving, simple structure and so on, the theoretical research of LFMCW radar has been paid more attention to by scholars at home and abroad. Key technologies and their applications have developed rapidly. Among them, the de-coupling method of moving target range velocity and the weak target detection algorithm under strong target background are the important research direction of LFMCW radar signal processing, and also the focus of this paper. In this paper, a traditional LFMCW radar signal processing algorithm based on beat Fourier transform and frequency domain pairing is studied. Because LFMCW radar is unable to obtain accurate target information because of the offset of beat signal frequency when it transmits the continuous wave with a single frequency modulation slope. Therefore, in this method, the radar transmit signal modulates the continuous wave with triangular waveform. According to the beat frequency of the moving target, the symmetrical deviation will occur in the frequency band of the symmetrical triangular FM continuous wave and the negative slope frequency band. In order to eliminate the influence of Doppler frequency of moving target, two spectra of the same target in the positive and negative slope sweep band are matched by using the beat Fourier frequency-domain pairing method to deal with the echo of the target. The real distance and velocity of the target are obtained. The advantage of this method is that it is simple in structure and easy to be realized, but it is easy to detect small and weak targets in the detection of multi-target beat signals with large dynamic range. In view of the problem of beat Fourier frequency-domain pairing, a new method of LFMCW radar signal processing based on channelized structure is proposed in this paper. This method uses channelized structure instead of the traditional beat Fourier method to detect the frequency of different target beat signals and then complete the matching to realize the distance and velocity decoupling of moving targets. In this paper, a prototype filter with high stopband attenuation is designed to solve the problem of the loss of small and weak targets in the detection of multi-target subbeat signals in large dynamic range by using the subbeat Fourier method. The weak and small targets in strong target background are detected by channelized structure. Finally, the validity of LFMCW radar signal processing method based on channelized structure is verified by MATLAB simulation. The simulation results show that the proposed method can accurately measure the distance and velocity of each target in a multi-target environment. When the stopband attenuation of the prototype low-pass filter meets the requirements, the proposed method can be used to detect small and weak targets, and a better result is achieved.
【學(xué)位授予單位】：西安電子科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TN957.51

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相關(guān)期刊論文 前1條

1 徐濤,金昶明,孫曉瑋,夏冠群;一種采用變周期調(diào)頻連續(xù)波雷達的多目標識別方法[J];電子學(xué)報;2002年06期

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本文編號：2057707