本文選題：數(shù)字天線陣列 + 導向矢量　； 參考：《中國科學技術(shù)大學》2014年博士論文

【摘要】：近年來數(shù)字天線陣列技術(shù)在現(xiàn)代國防軍事工業(yè)、移動通信和聲納等領(lǐng)域發(fā)揮了越來越重要的作用。自適應(yīng)波束成形作為數(shù)字陣列的核心技術(shù),它的不斷發(fā)展極大的推動了數(shù)字陣列的研究。與數(shù)據(jù)獨立型波束成形方法相比,自適應(yīng)波束形成具有更高的分辨率和更強的干擾抑制能力,并且這些特性都是建立在期望信號導向矢量等信息精確已知的前提下。但是,與傳統(tǒng)的相控陣一樣,數(shù)字陣列在工作時,也面臨了諸多誤差因素的影響,例如,陣元間互耦、幅相誤差、陣元位置誤差等。而一般的自適應(yīng)波束成形方法對誤差因素造成的導向矢量失配是比較敏感的。因此,近年來,大量的研究工作將重心放在了如何提高自適應(yīng)波束形成器在導向矢量失配條件下的穩(wěn)健性上。本文在已有工作的基礎(chǔ)上,研究了幾種新的穩(wěn)健自適應(yīng)波束成形方法。 本文首先在導向矢量的橢球不確定集基礎(chǔ)上,以最小化誤差敏感性為目標來設(shè)計穩(wěn)健自適應(yīng)波束形成器。與傳統(tǒng)的輸出性能最佳化法相比,誤差敏感性最小化法在導向矢量失配程度一定的前提下,對算法中導向矢量誤差范數(shù)上界的取值不敏感。理論上,誤差敏感性最小化法仍然屬于基于導向矢量不確定集的穩(wěn)健自適應(yīng)波束成形。但是,對于這一大類穩(wěn)健波束成形方法來說,當參考導向矢量與實際的導向矢量之間的失配程度較高時,其輸出信干噪比會出現(xiàn)較為明顯的下降。 接著,針對以上所述方法的輸出性能在較大導向矢量失配度下出現(xiàn)下降的問題。本文利用特征子空間分解定理構(gòu)造了關(guān)于導向失配度的估計方程,并以這些方程為基礎(chǔ)發(fā)展出了具有自適應(yīng)可調(diào)誤差半徑的迭代穩(wěn)健自適應(yīng)波束成形技術(shù)。在每一步迭代中都可以依據(jù)一定的準則估計出導向矢量不確定集的半徑。隨后以該誤差半徑為基礎(chǔ),求解出相應(yīng)的最優(yōu)導向矢量,并將其作為下一步迭代中使用的參考向量。該處理方法能夠有效提高較大導向矢量失配度下自適應(yīng)波束形成器的輸出性能。另一方面,該迭代搜索法也可被推廣到橢球不確定集中。但是,以上的迭代處理法在改善穩(wěn)健性的同時也增加了計算的復雜度。所以,本文又提出了一類新的基于泰勒級數(shù)展開的迭代穩(wěn)健自適應(yīng)波束成形。該方法無需構(gòu)建導向矢量的不確定集,其在輸出性能和處理復雜度之間進行了一定的平衡。 最后,考慮到均勻矩形平面陣中陣元間互耦的對稱性,本文進一步研究了具有低互耦敏感度的穩(wěn)健自適應(yīng)波束成形。通過在均勻矩形面陣的四周添加若干層輔助陣元,可以在不構(gòu)建導向矢量不確定集的前提下,也能夠有效改善自適應(yīng)波束形成器的性能。但是輔助陣元的引入也會造成在特定互耦系數(shù)條件下的空間譜估計中出現(xiàn)盲角問題,該問題可以通過使用不維度的噪聲子空間進行循環(huán)空間譜估計來解決。
[Abstract]:In recent years, digital antenna array technology has played a more and more important role in modern defense and military industry, mobile communication and sonar. As the core technology of digital array, adaptive beamforming has greatly promoted the research of digital array. Compared with the data independent beamforming method, adaptive beamforming has higher resolution and stronger interference suppression capability, and these characteristics are based on the premise that the information such as the desired signal guidance vector is accurately known. However, like the traditional phased array, the digital array also faces the influence of many error factors, such as mutual coupling between array elements, amplitude and phase error, position error and so on. The conventional adaptive beamforming method is sensitive to the mismatch of steering vector caused by error factors. Therefore, in recent years, a lot of research has focused on how to improve the robustness of adaptive beamformer under the guidance vector mismatch condition. Based on the previous work, several new robust adaptive beamforming methods are studied in this paper. In this paper a robust adaptive beamformer is designed based on the ellipsoidal uncertainty set of the guidance vector with the aim of minimizing error sensitivity. Compared with the traditional output performance optimization method, the error sensitivity minimization method is insensitive to the upper bound of the guidance vector error norm on the premise of a certain mismatch degree of the guide vector. In theory, error sensitivity minimization still belongs to robust adaptive beamforming based on guidance vector uncertainty set. However, for this class of robust beamforming methods, when the mismatch between the reference steering vector and the actual guidance vector is high, the output signal-to-noise ratio will decrease obviously. Then, the output performance of the method is reduced under the larger mismatch of steering vector. In this paper, the estimation equations of steering mismatch are constructed by using characteristic subspace decomposition theorem. Based on these equations, an iterative robust adaptive beamforming technique with adaptive adjustable error radius is developed. The radius of the guidance vector uncertainty set can be estimated according to certain criteria in each step iteration. Based on the error radius, the corresponding optimal guidance vector is solved and used as the reference vector in the next iteration. This method can effectively improve the output performance of adaptive beamformer with large steering vector mismatch. On the other hand, the iterative search method can also be extended to ellipsoidal uncertain sets. However, the above iterative methods not only improve robustness, but also increase computational complexity. Therefore, a new class of iterative robust adaptive beamforming based on Taylor series expansion is proposed. The method does not need to construct an uncertain set of guidance vectors, and it balances the output performance with the processing complexity. Finally, considering the symmetry of mutual coupling between elements in a uniform rectangular planar array, robust adaptive beamforming with low mutual coupling sensitivity is further studied in this paper. By adding several layer auxiliary elements around the uniform rectangular array, the performance of the adaptive beamformer can be improved effectively without constructing the guidance vector uncertainty set. However, the introduction of auxiliary elements will also lead to the blind angle problem in the spatial spectral estimation under the condition of specific mutual coupling coefficient. This problem can be solved by using non-dimensional noise subspace to estimate the cyclic spatial spectrum.
【學位授予單位】：中國科學技術(shù)大學
【學位級別】：博士
【學位授予年份】：2014
【分類號】：TN820.15

【共引文獻】

相關(guān)期刊論文 前9條

1 王燕;吳文峰;梁國龍;;基于穩(wěn)健最小二乘的魯棒波束形成[J];電子學報;2013年12期

2 王燕;吳文峰;梁國龍;;基于最小二乘估計的聲矢量陣穩(wěn)健波束形成[J];兵工學報;2014年03期

3 陳明建;羅景青;;基于雙不確定集約束的穩(wěn)健寬帶波束形成算法[J];電子學報;2014年03期

4 王燕;吳文峰;范展;梁國龍;;迭代尋優(yōu)的穩(wěn)健波束形成[J];哈爾濱工程大學學報;2014年06期

5 夏景;孔娃;王剛;;超寬帶微波近場目標探測成像實驗系統(tǒng)[J];微波學報;2009年04期

6 李艷茹;來欣;王剛;;用于早期乳腺癌檢測的超寬帶微波探頭設(shè)計[J];醫(yī)療衛(wèi)生裝備;2008年10期

7 肖夏;徐立;李欽偉;;A double constrained robust capon beamforming based imaging method for early breast cancer detection[J];Chinese Physics B;2013年09期

8 徐定杰;劉向鋒;沈鋒;韓浩;;基于干擾噪聲矩陣估計的穩(wěn)健Capon波束形成算法[J];現(xiàn)代雷達;2014年09期

9 任曉松;楊嘉偉;崔嵬;吳嗣亮;歐春湘;朱振虹;陳巖;;基于穩(wěn)健Capon波束形成技術(shù)的矢量相關(guān)測向方法[J];現(xiàn)代電子技術(shù);2014年18期

相關(guān)博士學位論文 前6條

1 劉廣東;乳腺癌檢測的時域微波成像算法研究[D];南京郵電大學;2011年

2 顧宇杰;魯棒自適應(yīng)波束成形研究[D];浙江大學;2008年

3 黃玲;多輸入多輸出探地雷達方法研究[D];吉林大學;2010年

4 何子遠;稀疏陣DOA估計及模糊特性研究[D];電子科技大學;2012年

5 王芳芳;超寬帶穿墻雷達成像算法研究[D];南京郵電大學;2012年

6 李杰;穩(wěn)健波束形成與稀疏空間譜估計技術(shù)研究[D];華南理工大學;2013年

相關(guān)碩士學位論文 前2條

1 李艷茹;早期乳腺癌超寬帶微波檢測系統(tǒng)[D];江蘇大學;2008年

2 榮笑;自適應(yīng)波束形成算法的魯棒性研究[D];西安電子科技大學;2014年

，

本文編號：1925027