本文關(guān)鍵詞：MIMO雷達(dá)發(fā)射方向圖與波形設(shè)計(jì)方法研究　出處：《西安電子科技大學(xué)》2014年博士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： MIMO雷達(dá) 方向圖設(shè)計(jì) 波形設(shè)計(jì) 距離旁瓣抑制 雜波抑制

【摘要】：多輸入多輸出(MIMO)雷達(dá)具有多個(gè)發(fā)射和接收天線,各發(fā)射天線可以發(fā)射不同信號(hào),這使得MIMO雷達(dá)具有波形分集的優(yōu)勢(shì)。根據(jù)天線的間距,通常將MIMO雷達(dá)分為分布式MIMO雷達(dá)和集中式MIMO雷達(dá)。在復(fù)雜多變的工作環(huán)境下,傳統(tǒng)雷達(dá)所采用的往復(fù)掃描的單個(gè)窄波束和相對(duì)固定的發(fā)射波形,很難取得滿意的性能,也無(wú)法滿足多任務(wù)、多功能的需求。而MIMO雷達(dá)的波形分集優(yōu)勢(shì),使得雷達(dá)系統(tǒng)具有更高的發(fā)射自由度,可以針對(duì)工作場(chǎng)景和需求,靈活的設(shè)計(jì)發(fā)射方向圖;可以根據(jù)環(huán)境信息及時(shí)調(diào)整發(fā)射波形。因此,MIMO雷達(dá)方向圖和波形設(shè)計(jì)成為一個(gè)很有意義的研究領(lǐng)域。本文從發(fā)射方向圖逼近、合成信號(hào)距離旁瓣抑制、多功能波形、雜波抑制和抗干擾等方面對(duì)MIMO雷達(dá)波形設(shè)計(jì)進(jìn)行了研究。論文的主要工作概括如下:1.從正交波形和具有特定方向圖的波形等兩方面對(duì)MIMO雷達(dá)方向圖設(shè)計(jì)進(jìn)行研究。首先介紹了一種基于梯度下降的正交波形循環(huán)設(shè)計(jì)方法,該方法基于最小化加權(quán)積分旁瓣(Weighted Integrated Sidelobe Level,WISL)準(zhǔn)則,根據(jù)各波形的梯度信息,依次對(duì)每個(gè)波形進(jìn)行優(yōu)化。仿真實(shí)驗(yàn)表明該算法與基于最小化峰值旁瓣準(zhǔn)則的序列二次規(guī)劃法性能相當(dāng),且可以應(yīng)用于大規(guī)模陣列。針對(duì)多波束的方向圖設(shè)計(jì),利用基于修正的最小化旁瓣模型,設(shè)計(jì)具有較低旁瓣的多波束方向圖;通過調(diào)整發(fā)射樣本順序和優(yōu)化初相,有效地抑制了波束方向信號(hào)的自相關(guān)旁瓣和互相關(guān)。最后提出一種基于空時(shí)聯(lián)合優(yōu)化的MIMO雷達(dá)波形設(shè)計(jì)方法,對(duì)集中式MIMO雷達(dá)的正交波形設(shè)計(jì)與具有特定方向圖的波形設(shè)計(jì)建立了統(tǒng)一的優(yōu)化模型,該方法在實(shí)現(xiàn)方向圖逼近的同時(shí),可以對(duì)感興趣方向信號(hào)的時(shí)域自相關(guān)旁瓣進(jìn)行有效抑制。2.初步研究、分析了通過MIMO雷達(dá)波形設(shè)計(jì)來(lái)實(shí)現(xiàn)同時(shí)多功能。首先提出一種MIMO雷達(dá)多模波形設(shè)計(jì)方法,以方向圖逼近、波束方向信號(hào)的功率譜逼近及頻譜逼近等為準(zhǔn)則優(yōu)化波形,所設(shè)計(jì)的波形可以在期望方向形成多個(gè)波束,各波束方向的信號(hào)可以具有不同特性,以同時(shí)實(shí)現(xiàn)搜索、成像和跟蹤等功能。在多目標(biāo)場(chǎng)景中,傳統(tǒng)雷達(dá)通過波束切換的方式,依次對(duì)各目標(biāo)成像,可減少對(duì)于每個(gè)目標(biāo)的駐留時(shí)間,從而導(dǎo)致多普勒分辨力的降低。針對(duì)此問題,提出一種寬帶MIMO雷達(dá)波形設(shè)計(jì)方法,該方法可以實(shí)現(xiàn)期望的多波束方向圖,波束方向信號(hào)具有期望的功率譜特性。通過利用CZT(Chirp-Z Transform)變換來(lái)計(jì)算各方向信號(hào)的離散頻譜,有效地降低了計(jì)算量。另外,為了在保證分辨率不損失的情況下降低目標(biāo)回波間的相互干擾,將各期望功率譜隨機(jī)分布于多個(gè)不重疊的子帶區(qū)域�；谒O(shè)計(jì)波形,通過應(yīng)用稀疏重構(gòu)方法可以實(shí)現(xiàn)多目標(biāo)成像。3.實(shí)際場(chǎng)景中目標(biāo)信息不斷變化,需要對(duì)波束指向、各目標(biāo)分配的功率及時(shí)調(diào)整。針對(duì)此問題,提出了一種基于迭代FFT的MIMO雷達(dá)快速波形設(shè)計(jì)方法。該方法分兩個(gè)獨(dú)立的階段:快速方向圖綜合和空域合成信號(hào)優(yōu)化。首先利用迭代FFT方式設(shè)計(jì)波形以逼近期望的方向圖;然后通過優(yōu)化波形的初相序列來(lái)提高空域合成信號(hào)的自相關(guān)特性。在初相優(yōu)化中,采用了最小化積分旁瓣電平(ISL)和加權(quán)積分旁瓣電平(WISL)準(zhǔn)則來(lái)抑制旁瓣。由于該算法的主要計(jì)算可由FFT/IFFT實(shí)現(xiàn),因此可以滿足實(shí)時(shí)性要求。4.針對(duì)空域合成信號(hào)的距離旁瓣抑制,提出了兩種方式:脈沖串編碼和失配濾波器設(shè)計(jì)。對(duì)于靜止或速度較低的目標(biāo),脈沖串編碼的方式可以在保證方向圖不變的情況下,進(jìn)一步抑制距離旁瓣。而對(duì)于較高速的目標(biāo),采用一種基于輔助變量的MIMO雷達(dá)失配濾波器,可以在一定的信噪比損失(Signal-to-Noise Ratio Loss,SNRLoss)范圍下,最小化零頻附近多普勒失配下的距離旁瓣。該方式可以在多普勒維展寬距離旁瓣的抑制范圍,對(duì)多普勒頻移具有一定穩(wěn)健性。5.針對(duì)抗干擾和雜波抑制問題,初步研究了MIMO雷達(dá)認(rèn)知發(fā)射。為了降低被干擾源偵察到的可能,提出了一種自適應(yīng)發(fā)射置零方法,利用接收到的干擾數(shù)據(jù),構(gòu)造干擾子空間,通過對(duì)波形與干擾子空間的正交化,實(shí)現(xiàn)自適應(yīng)發(fā)射置零。另外,針對(duì)快速運(yùn)動(dòng)干擾,通過添加導(dǎo)數(shù)約束或利用錐化矩陣可以實(shí)現(xiàn)干擾子空間擴(kuò)展,從而獲得零陷展寬。針對(duì)空域非均勻雜波的抑制,提出了一種MIMO雷達(dá)發(fā)射方向圖優(yōu)化設(shè)計(jì)方法。首先通過發(fā)射正交波形對(duì)雜波環(huán)境進(jìn)行感知,以發(fā)射波形與正交波形回波間的平均相關(guān)性作為接收陣列中雜波功率的近似,再根據(jù)最大化信雜噪比模型優(yōu)化發(fā)射波形。仿真結(jié)果表明,在空域非均勻強(qiáng)雜波背景下,優(yōu)化后的波形可以有效地提高回波信雜噪比。
[Abstract]:Multiple input multiple output (MIMO) radar with multiple transmit and receive antennas, the antenna can transmit different signals, which makes the MIMO radar with waveform diversity advantage. According to the antenna spacing, MIMO is usually divided into distributed radar MIMO radar and centralized MIMO radar. In the complex work environment, single sweep the traditional radar waveform and the narrow beam is relatively fixed, it is difficult to obtain satisfactory performance, can not meet the requirements of multi task, multi function demand. MIMO radar waveform diversity advantage, so the radar system has a higher degree of freedom for launch, work scenarios and requirements, the design of transmitting pattern flexible; according to the environmental information in a timely manner to adjust the transmitted waveform. Therefore, MIMO radar waveform design pattern and it has become an interesting research field. This paper from the beampattern approximation, synthesis Signal sidelobe suppression, multi function waveform, clutter suppression and anti-jamming of MIMO radar waveform design. The main work of this thesis is summarized as follows: 1. from two aspects and has a specific pattern of orthogonal waveform waveform of MIMO radar pattern design research. This paper introduces a kind of orthogonal waveform loop design method based on gradient descent, this method is based on minimizing the weighted integral side lobe (Weighted Integrated Sidelobe Level, WISL) criterion, according to the gradient information of each waveform, for each waveform optimization. Simulation results show that the algorithm with minimum peak sidelobe performance of sequential quadratic programming method based on two criteria, and can be applied to large scale array. For the multi beam pattern design, by minimizing the sidelobe model based on the multi beam pattern design with low sidelobe by adjusting; Sample order and optimize the launch phase, effectively suppress the beam direction signal autocorrelation sidelobe and cross correlation. Finally, a combined optimization based on space-time MIMO radar waveform design method, design orthogonal waveform waveform design of centralized MIMO radar and has a specific pattern of the optimization model is established and unified, the method in the approximation of direction map at the same time, can be interested in the direction of the signal time-domain autocorrelation sidelobe suppressed.2. preliminary study, analyzed by MIMO radar waveform design to achieve multi function. We propose a MIMO multimode radar waveform design method, the pattern approximation, the power spectrum of the signal beam direction and spectral approximation for the approximation optimization criteria of waveform design waveform can form multiple beams in the desired direction, the direction of the signal beam can have different characteristics, at the same time The search function, imaging and tracking. In the scene, the traditional radar beam switching mode, in order to various target imaging, can reduce the dwell time for each target, which leads to the Doppler resolution is reduced. In order to solve this problem, proposes a wideband MIMO radar waveform design method, multi beam pattern this method can achieve the desired direction of the beam, with the desired signal power spectral characteristics. By using CZT (Chirp-Z Transform) to calculate the discrete spectrum transform direction signal, effectively reduces the amount of calculation. In addition, in order to reduce mutual interference in the guarantee target echo the loss of resolution of the case, the expected the power spectrum of random distribution in multiple non overlapping sub area. The design of waveform based on sparse reconstruction method can be achieved through the application of target information becomes multi target imaging.3. in the actual scene And the need for beam pointing, timely adjustment of power allocation of each target. To solve this problem, we propose a fast iterative MIMO radar waveform design method based on FFT. The method is divided into two separate stages: fast pattern synthesis and spatial synthetic signal optimization. First using iterative FFT method to approximate the desired waveform design the direction of the map; then by optimizing the waveform phase sequence to improve the spatial autocorrelation characteristics of synthetic signals. In the early phase of optimization, the minimization of integral sidelobe level (ISL) and the weighted integral sidelobe level (WISL) criterion to suppress sidelobe. Because the main calculation of the algorithm can be realized by FFT/IFFT, so you can meet the requirements of real-time.4. for spatial synthetic signal sidelobe suppression, puts forward two kinds of methods: pulse string encoding and mismatched filter design for static or low speed, pulse string encoding To ensure the direction map unchanged, further sidelobe suppression. For the high speed target, using a mismatch filter MIMO radar based on instrumental variable, can be in a certain SNR loss (Signal-to-Noise Ratio Loss, SNRLoss) range, the minimization of near zero frequency Doppler lost sidelobe distribution this approach can be inhibited. In the range of Doppler broadening dimension range sidelobe, has certain robustness against.5. interference and clutter suppression of Doppler frequency shift, preliminary research on MIMO radar. In order to reduce the emission of cognitive interference source is detected, we proposed an adaptive transmit nulling method, using interference data receiving the structure of the interference subspace through orthogonal waveform and interference subspace, to achieve adaptive zero emission. In addition, for the rapid movement of interference, by adding derivative constraints By using the cone or matrix can realize interference subspace expansion, so as to obtain the null broadening. In order to suppress clutter of non uniform airspace, proposes a MIMO radar transmit beampattern optimization design method. Firstly, by transmitting orthogonal waveforms for sensing the clutter environment, to launch an average correlation between echo waveform and orthogonal waveforms as approximate clutter power receiving array, and then according to the optimized waveform maximum SCNR model. The simulation results show that the spatial non-uniform strong background clutter, the optimized waveform can effectively improve the signal clutter noise ratio.

【學(xué)位授予單位】：西安電子科技大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2014
【分類號(hào)】：TN958

【共引文獻(xiàn)】

相關(guān)期刊論文 前10條

1 武擁軍;吳先良;;雙站移不變SAR成像的一種通用等效單站RD算法[J];安徽大學(xué)學(xué)報(bào)(自然科學(xué)版);2009年05期

2 謝宜壯;朱柏承;汪精華;;星載SAR實(shí)時(shí)成像處理系統(tǒng)結(jié)構(gòu)設(shè)計(jì)[J];兵工學(xué)報(bào);2010年S2期

3 郭琨毅;盛新慶;唐波;;機(jī)動(dòng)目標(biāo)的時(shí)頻變換ISAR成像仿真[J];北京理工大學(xué)學(xué)報(bào);2009年02期

4 劉偉;李海;;基于Photoshop插件的SAR圖像處理與評(píng)估系統(tǒng)[J];北京理工大學(xué)學(xué)報(bào);2009年05期

5 鄭坤;高梅國(guó);劉國(guó)滿;;一種基于擴(kuò)展孔徑的SAR欺騙干擾算法[J];北京理工大學(xué)學(xué)報(bào);2009年05期

6 傅雄軍;方秋均;鄢宏華;高梅國(guó);;基于天基雷達(dá)探測(cè)的靜止軌道目標(biāo)監(jiān)視[J];北京理工大學(xué)學(xué)報(bào);2009年06期

7 陳德峰;高梅國(guó);傅雄軍;江長(zhǎng)勇;;參數(shù)偵測(cè)誤差對(duì)SAR欺騙干擾的影響[J];北京理工大學(xué)學(xué)報(bào);2009年07期

8 張雄奎;傅雄軍;高梅國(guó);夏雯涓;;多通道實(shí)時(shí)ISAR成像系統(tǒng)的設(shè)計(jì)與實(shí)現(xiàn)[J];北京理工大學(xué)學(xué)報(bào);2010年03期

9 鄢宏華;栗蘋;傅雄軍;高梅國(guó);;月面態(tài)勢(shì)感知雷達(dá)三維成像方法[J];北京理工大學(xué)學(xué)報(bào);2011年05期

10 王彥華;姚迪;曾濤;;沿航向運(yùn)動(dòng)誤差對(duì)SAR回波特性的影響[J];北京理工大學(xué)學(xué)報(bào);2011年12期

相關(guān)博士學(xué)位論文 前10條

1 劉吉英;壓縮感知理論及在成像中的應(yīng)用[D];國(guó)防科學(xué)技術(shù)大學(xué);2010年

2 王力寶;多輸入多輸出合成孔徑雷達(dá)關(guān)鍵技術(shù)研究[D];國(guó)防科學(xué)技術(shù)大學(xué);2010年

3 王懷軍;MIMO雷達(dá)成像算法研究[D];國(guó)防科學(xué)技術(shù)大學(xué);2010年

4 賀思三;微動(dòng)目標(biāo)高分辨雷達(dá)信號(hào)建模及特征提取[D];國(guó)防科學(xué)技術(shù)大學(xué);2010年

5 楊科鋒;移變雙基地SAR特性與成像方法研究[D];國(guó)防科學(xué)技術(shù)大學(xué);2009年

6 李金梁;箔條干擾的特性與雷達(dá)抗箔條技術(shù)研究[D];國(guó)防科學(xué)技術(shù)大學(xué);2010年

7 賴濤;星載多通道SAR高分辨寬測(cè)繪帶成像方法研究[D];國(guó)防科學(xué)技術(shù)大學(xué);2010年

8 陶勇;知識(shí)輔助的SAR圖像目標(biāo)特性分析與識(shí)別研究[D];國(guó)防科學(xué)技術(shù)大學(xué);2010年

9 朱洪波;基于亮度變化測(cè)度的多源影像抗干擾融合模型研究[D];華中科技大學(xué);2011年

10 楊予昊;自旋目標(biāo)運(yùn)動(dòng)成像與靜止目標(biāo)凝視成像方法及關(guān)鍵技術(shù)研究[D];中國(guó)科學(xué)技術(shù)大學(xué);2011年

相關(guān)碩士學(xué)位論文 前1條

1 王廣龍;艦船目標(biāo)ISAR成像方法研究[D];電子科技大學(xué);2014年

，

本文編號(hào)：1419835