時(shí)域?qū)拵Ш愣ㄊ鴮挷ㄊ纬煞椒ㄑ芯?/H1>
發(fā)布時(shí)間：2019-06-17 18:48
【摘要】：隨著陣列信號(hào)處理的日益發(fā)展,其在現(xiàn)代信號(hào)處理的地位也越加顯著,并在諸多領(lǐng)域,如:雷達(dá)、通信、射電天文以及醫(yī)學(xué)診斷等得到了廣泛應(yīng)用。通過(guò)對(duì)傳感器陣列賦以不同的系數(shù)獲得最優(yōu)的輸出性能是自適應(yīng)波束形成的目標(biāo),也是陣列信號(hào)處理的重要組成部分之一。寬帶信號(hào)帶寬足夠大能夠傳輸很大的信息量,并且混響背景相關(guān)性弱不容易受到信道傳輸過(guò)程的影響,在目標(biāo)的檢測(cè)、參數(shù)估計(jì)和目標(biāo)特征的提取這些方面上更具有優(yōu)勢(shì),然而傳統(tǒng)的寬帶信號(hào)波束形成設(shè)計(jì)中會(huì)因?yàn)閹拑?nèi)子帶頻率的不同導(dǎo)致入射信號(hào)來(lái)波方向在波束主瓣寬度內(nèi)的其他方向上時(shí)出現(xiàn)失真,在實(shí)際應(yīng)用中無(wú)法滿足頻率上恒定束寬,這會(huì)導(dǎo)致算法性能的下降。因此,寬帶恒定束寬波束形成算法具有很大的實(shí)際意義。并且當(dāng)期望寬帶信號(hào)和干擾信號(hào)共同在遠(yuǎn)場(chǎng)平面入射時(shí),如何抑制干擾信號(hào)和噪聲信號(hào)的影響也是恒定束寬波束形成中的一個(gè)重要問題。本文對(duì)恒定束寬波束形成算法的實(shí)現(xiàn)和波束圖中干擾方向上的零陷形成進(jìn)行了深入研究。首先,在聚焦變換思路下把寬帶信號(hào)劃分后的不同頻率子帶上的數(shù)據(jù)通過(guò)聚焦變換矩陣聚焦到一個(gè)參考頻率上,推導(dǎo)了寬帶信號(hào)各個(gè)子帶頻域數(shù)據(jù)的輸出矩陣形式和RSS方法下的聚焦變換矩陣表達(dá)式,之后通過(guò)MVDR波束形成方法設(shè)計(jì)得到頻率不變恒定束寬并且具有很好零陷區(qū)域的波束形成器。其次,利用SRV約束實(shí)現(xiàn)恒定束寬最低旁瓣波束形成,然后在滿足期望信號(hào)指定來(lái)波方向上波束輸出增益最大和干擾信號(hào)來(lái)波方向零陷抑制的條件下,分析寬帶恒定束寬波束形成中最佳權(quán)矢量的設(shè)定,得出了滿足設(shè)計(jì)需求的SRV約束下恒定束寬MVDR最低旁瓣波束形成,并對(duì)其進(jìn)行改進(jìn)得到新算法,仿真證明改進(jìn)后的方法在小采樣數(shù)和較高輸入SNR的情況下具有更好的輸出性能。再次,重點(diǎn)研究了最差環(huán)境下波束形成算法,詳細(xì)推導(dǎo)了波束形成算法的形成過(guò)程,引入橢球體約束集實(shí)現(xiàn)對(duì)任意方向向量失配的信號(hào)的無(wú)失真接收并將優(yōu)化問題化簡(jiǎn)成為凸優(yōu)化問題,采用內(nèi)點(diǎn)法求取最優(yōu)的權(quán)重向量。最后,將該波束形成算法用于寬帶恒定束寬波束形成算法中,提出了導(dǎo)向向量失配下恒定束寬波束形成算法,經(jīng)過(guò)仿真研究,驗(yàn)證了該算法對(duì)小采樣樣本引起的采樣自相關(guān)矩陣誤差以及方向向量失配都具有很好的魯棒性,并且可以實(shí)現(xiàn)帶寬上恒定束寬,在干擾信號(hào)來(lái)波方向上形成較大的零陷深度,波束形成系統(tǒng)有很好的輸出性能。
[Abstract]:With the development of array signal processing, its position in modern signal processing is becoming more and more prominent, and it has been widely used in many fields, such as radar, communication, radio astronomy and medical diagnosis. It is the target of adaptive beamforming to obtain the optimal output performance by assigning different coefficients to the sensor array, and it is also one of the important components of array signal processing. The broadband signal bandwidth is large enough to transmit a large amount of information, and the reverberation background correlation is not easily affected by the channel transmission process, so it has more advantages in target detection, parameter estimation and target feature extraction. However, in the traditional broadband signal beamforming design, due to the different subband frequency in the bandwidth, the incident signal will be distorted in other directions in the main lobe width of the beam, and the constant beam width in the frequency can not be satisfied in practical application, which will lead to the degradation of the performance of the algorithm. Therefore, the broadband constant beam width beamforming algorithm has great practical significance. When the broadband signal and the interference signal are expected to incident in the far field plane, how to suppress the influence of the interference signal and the noise signal is also an important problem in the constant beam width beamforming. In this paper, the realization of constant beam width beamforming algorithm and the zero notch formation in interference direction in beam graph are deeply studied. Firstly, under the idea of focusing transformation, the data on different frequency subbands of broadband signal are focused on a reference frequency by focusing transformation matrix, and the output matrix form of frequency domain data of each subband of broadband signal and the expression of focusing transformation matrix under RSS method are derived. then the beamformer with constant frequency beam width and good zero notch region is designed by MVDR beamforming method. Secondly, the constant beamwidth minimum sidelobe beamforming is realized by using SRV constraint, and then the optimal weight vector setting in broadband constant beamwidth beamforming is analyzed under the condition of satisfying the maximum output gain of the beam output and the zero notch suppression of the interference signal in the specified incoming direction of the desired signal, and the constant beamwidth MVDR minimum sidelobe beamforming under the SRV constraint to meet the design requirements is obtained, and a new algorithm is obtained. The simulation results show that the improved method has better output performance under the condition of small sampling number and high input SNR. Thirdly, the beamforming algorithm in the worst environment is studied, and the forming process of the beamforming algorithm is deduced in detail. The ellipsoid constraint set is introduced to realize the distortionless reception of the mismatched signal in any direction vector, and the optimization problem is simplified into a convex optimization problem. The optimal weight vector is obtained by the interior point method. Finally, the beamforming algorithm is applied to broadband constant beamwidth beamforming algorithm, and a constant beamwidth beamforming algorithm under guidance vector mismatch is proposed. The simulation results show that the algorithm has good robustness to the sampling autocorrelation matrix error and direction vector mismatch caused by small sampling samples, and can achieve constant beam width on bandwidth and form a large zero-notch depth in the wave side of the interference signal. Beamforming system has good output performance.
【學(xué)位授予單位】：哈爾濱工程大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：TN911.7
【引證文獻(xiàn)】
相關(guān)碩士學(xué)位論文 前1條
1 龐宇;語(yǔ)音分離技術(shù)的研究與實(shí)現(xiàn)[D];國(guó)防科學(xué)技術(shù)大學(xué);2016年
，
本文編號(hào)：2501186
本文鏈接：http://www.sikaile.net/kejilunwen/wltx/2501186.html
[Abstract]:With the development of array signal processing, its position in modern signal processing is becoming more and more prominent, and it has been widely used in many fields, such as radar, communication, radio astronomy and medical diagnosis. It is the target of adaptive beamforming to obtain the optimal output performance by assigning different coefficients to the sensor array, and it is also one of the important components of array signal processing. The broadband signal bandwidth is large enough to transmit a large amount of information, and the reverberation background correlation is not easily affected by the channel transmission process, so it has more advantages in target detection, parameter estimation and target feature extraction. However, in the traditional broadband signal beamforming design, due to the different subband frequency in the bandwidth, the incident signal will be distorted in other directions in the main lobe width of the beam, and the constant beam width in the frequency can not be satisfied in practical application, which will lead to the degradation of the performance of the algorithm. Therefore, the broadband constant beam width beamforming algorithm has great practical significance. When the broadband signal and the interference signal are expected to incident in the far field plane, how to suppress the influence of the interference signal and the noise signal is also an important problem in the constant beam width beamforming. In this paper, the realization of constant beam width beamforming algorithm and the zero notch formation in interference direction in beam graph are deeply studied. Firstly, under the idea of focusing transformation, the data on different frequency subbands of broadband signal are focused on a reference frequency by focusing transformation matrix, and the output matrix form of frequency domain data of each subband of broadband signal and the expression of focusing transformation matrix under RSS method are derived. then the beamformer with constant frequency beam width and good zero notch region is designed by MVDR beamforming method. Secondly, the constant beamwidth minimum sidelobe beamforming is realized by using SRV constraint, and then the optimal weight vector setting in broadband constant beamwidth beamforming is analyzed under the condition of satisfying the maximum output gain of the beam output and the zero notch suppression of the interference signal in the specified incoming direction of the desired signal, and the constant beamwidth MVDR minimum sidelobe beamforming under the SRV constraint to meet the design requirements is obtained, and a new algorithm is obtained. The simulation results show that the improved method has better output performance under the condition of small sampling number and high input SNR. Thirdly, the beamforming algorithm in the worst environment is studied, and the forming process of the beamforming algorithm is deduced in detail. The ellipsoid constraint set is introduced to realize the distortionless reception of the mismatched signal in any direction vector, and the optimization problem is simplified into a convex optimization problem. The optimal weight vector is obtained by the interior point method. Finally, the beamforming algorithm is applied to broadband constant beamwidth beamforming algorithm, and a constant beamwidth beamforming algorithm under guidance vector mismatch is proposed. The simulation results show that the algorithm has good robustness to the sampling autocorrelation matrix error and direction vector mismatch caused by small sampling samples, and can achieve constant beam width on bandwidth and form a large zero-notch depth in the wave side of the interference signal. Beamforming system has good output performance.
【學(xué)位授予單位】：哈爾濱工程大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：TN911.7
【引證文獻(xiàn)】
相關(guān)碩士學(xué)位論文 前1條
1 龐宇;語(yǔ)音分離技術(shù)的研究與實(shí)現(xiàn)[D];國(guó)防科學(xué)技術(shù)大學(xué);2016年
，本文編號(hào)：2501186
本文鏈接：http://www.sikaile.net/kejilunwen/wltx/2501186.html
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