相干信號(hào)來波方向估計(jì)技術(shù)研究
發(fā)布時(shí)間：2018-09-18 13:18
【摘要】：來波方向估計(jì)技術(shù),也就是DOA估計(jì)技術(shù)由于其精確的角度估計(jì)特點(diǎn),被廣泛地應(yīng)用在衛(wèi)星、通信、探測(cè)等多個(gè)方面。本文在簡(jiǎn)單的總結(jié)了傳統(tǒng)的經(jīng)典DOA估計(jì)算法之后,針對(duì)相干信號(hào)條件下的DOA估計(jì)問題,DOA算法快速化問題以及寬帶信號(hào)條件下的穩(wěn)健DOA估計(jì)問題分別進(jìn)行了研究,同時(shí)也對(duì)通道不一致性對(duì)DOA估計(jì)問題的影響以及解決辦法進(jìn)行了研究。本文主要工作如下：1.首先,給出了陣列信號(hào)處理的基本模型。簡(jiǎn)單地介紹了傳統(tǒng)的經(jīng)典MUSIC算法以及ESPRIT算法的基本原理,給出了具體的推導(dǎo)過程,分析了算法的各自特點(diǎn)。之后,給出具體的仿真參數(shù),對(duì)算法進(jìn)行了仿真,并分析了具體場(chǎng)合下,算法的角度分辨力隨輸入SINR之間的關(guān)系。2.針對(duì)相干信號(hào)條件下,傳統(tǒng)的DOA估計(jì)算法失效的問題,提出了若干解決方案。第一,利用Toeplitze技術(shù)將相干信號(hào)條件下得到的陣列接收信號(hào)協(xié)方差矩陣進(jìn)行Toeplitze化,然后將重新得到的新協(xié)方差矩陣應(yīng)用到傳統(tǒng)DOA算法中,能夠在信號(hào)相干條件下,得到正確的來波方向估計(jì)值。第二,利用虛擬空間平滑技術(shù),通過虛擬化陣元數(shù)目,實(shí)現(xiàn)信號(hào)的解相干,進(jìn)而完成DOA估計(jì)。計(jì)算機(jī)仿真驗(yàn)證了上述算法的正確性和有效性。3.針對(duì)傳統(tǒng)DOA算法需要進(jìn)行譜峰搜索以及特征分解,從而導(dǎo)致運(yùn)算量特別大的問題,提出了基于GS正交化的DOA估計(jì)以及基于MSWF的DOA估計(jì)算法。上述算法以獲取近似的信號(hào)子空間為目的,在適當(dāng)?shù)臓奚涌臻g估計(jì)精度的情況下,極大的減少了的運(yùn)行時(shí)間,降低了算法的復(fù)雜度。通過計(jì)算機(jī)仿真將上述方法和傳統(tǒng)DOA方法進(jìn)行了比較,可以看出,程序運(yùn)行時(shí)間在很大程度上減少了。此類算法對(duì)實(shí)際工程應(yīng)用具有一定的指導(dǎo)意義。4.針對(duì)寬帶信號(hào)DOA中的色散問題,在系統(tǒng)總結(jié)了前人基于聚焦技術(shù)的DOA算法之后,提出了基于全局聚焦的穩(wěn)健DOA算法。該算法不需要任何先驗(yàn)知識(shí),能夠準(zhǔn)確地估計(jì)出寬帶信號(hào)的來波方向信息,并且再經(jīng)過聚焦和頻域平滑處理之后,后續(xù)的算法步驟和窄帶信號(hào)DOA算法基本相同。仿真實(shí)驗(yàn)驗(yàn)證了該算法的正確性和有效性。5.針對(duì)實(shí)際工程環(huán)境中往往不可避免的通道不一致性問題,首先理論分析了通道不一致性給DOA算法帶來的影響,并通過計(jì)算機(jī)對(duì)該影響進(jìn)行了仿真。仿真表明幅度誤差主要影響譜峰的高度,而相位誤差不僅影響譜峰的高度,還同時(shí)影響譜峰的位置。之后,針對(duì)這個(gè)問題,提出了一種有效的通道校準(zhǔn)算法。實(shí)驗(yàn)表明,經(jīng)過通道校準(zhǔn)后的DOA算法在性能上存在顯著的提升。
[Abstract]:Due to its accurate angle estimation, DOA estimation technology is widely used in satellite, communication, detection and other fields. After a brief summary of the classical DOA estimation algorithm, the fast DOA estimation problem under coherent signal condition and the robust DOA estimation problem under wideband signal condition are studied respectively in this paper. At the same time, the influence of channel inconsistency on DOA estimation problem and its solution are also studied. The main work of this paper is as follows: 1. Firstly, the basic model of array signal processing is given. This paper briefly introduces the classical MUSIC algorithm and the basic principle of the ESPRIT algorithm, gives the concrete derivation process, and analyzes the respective characteristics of the algorithm. After that, the specific simulation parameters are given, the algorithm is simulated, and the relationship between the angular resolution of the algorithm and the input SINR is analyzed. In order to solve the problem of failure of traditional DOA estimation algorithm under coherent signal condition, several solutions are proposed. First, the array received signal covariance matrix under coherent signal condition is Toeplitze based on Toeplitze technique, and then the new covariance matrix is applied to the traditional DOA algorithm, which can be used in the coherent signal condition. The correct estimation of the direction of the wave is obtained. Secondly, using the virtual space smoothing technology, the signal decoherence is realized by virtualizing the number of array elements, and then the DOA estimation is completed. The correctness and validity of the algorithm are verified by computer simulation. In order to solve the problem that the traditional DOA algorithm needs spectral peak search and feature decomposition, which results in a large amount of computation, a DOA estimation algorithm based on GS orthogonalization and a DOA estimation algorithm based on MSWF are proposed. In order to obtain the approximate signal subspace, the algorithm can greatly reduce the running time and reduce the complexity of the algorithm under the condition of sacrificing the estimation accuracy of the subspace. Compared with the traditional DOA method by computer simulation, it can be seen that the running time of the program is reduced to a great extent. This kind of algorithm has certain guiding significance for practical engineering application. 4. Aiming at the dispersion problem in wideband signal DOA, a robust DOA algorithm based on global focusing is proposed after summarizing the previous DOA algorithm based on focusing technique. The algorithm does not need any prior knowledge, and can accurately estimate the direction of arrival of wideband signals. After focusing and frequency domain smoothing, the following algorithm steps are basically the same as the narrowband signal DOA algorithm. Simulation results show that the algorithm is correct and effective. In view of the channel inconsistency which is often unavoidable in practical engineering environment, the influence of channel inconsistency on DOA algorithm is analyzed theoretically, and the influence is simulated by computer. The simulation results show that the amplitude error mainly affects the height of the spectral peak, while the phase error affects not only the height of the spectral peak, but also the position of the peak. Then, an effective channel calibration algorithm is proposed to solve this problem. Experiments show that the performance of the DOA algorithm after channel calibration is improved significantly.
【學(xué)位授予單位】：南京理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：TN911.23
，
本文編號(hào)：2248039
[Abstract]:Due to its accurate angle estimation, DOA estimation technology is widely used in satellite, communication, detection and other fields. After a brief summary of the classical DOA estimation algorithm, the fast DOA estimation problem under coherent signal condition and the robust DOA estimation problem under wideband signal condition are studied respectively in this paper. At the same time, the influence of channel inconsistency on DOA estimation problem and its solution are also studied. The main work of this paper is as follows: 1. Firstly, the basic model of array signal processing is given. This paper briefly introduces the classical MUSIC algorithm and the basic principle of the ESPRIT algorithm, gives the concrete derivation process, and analyzes the respective characteristics of the algorithm. After that, the specific simulation parameters are given, the algorithm is simulated, and the relationship between the angular resolution of the algorithm and the input SINR is analyzed. In order to solve the problem of failure of traditional DOA estimation algorithm under coherent signal condition, several solutions are proposed. First, the array received signal covariance matrix under coherent signal condition is Toeplitze based on Toeplitze technique, and then the new covariance matrix is applied to the traditional DOA algorithm, which can be used in the coherent signal condition. The correct estimation of the direction of the wave is obtained. Secondly, using the virtual space smoothing technology, the signal decoherence is realized by virtualizing the number of array elements, and then the DOA estimation is completed. The correctness and validity of the algorithm are verified by computer simulation. In order to solve the problem that the traditional DOA algorithm needs spectral peak search and feature decomposition, which results in a large amount of computation, a DOA estimation algorithm based on GS orthogonalization and a DOA estimation algorithm based on MSWF are proposed. In order to obtain the approximate signal subspace, the algorithm can greatly reduce the running time and reduce the complexity of the algorithm under the condition of sacrificing the estimation accuracy of the subspace. Compared with the traditional DOA method by computer simulation, it can be seen that the running time of the program is reduced to a great extent. This kind of algorithm has certain guiding significance for practical engineering application. 4. Aiming at the dispersion problem in wideband signal DOA, a robust DOA algorithm based on global focusing is proposed after summarizing the previous DOA algorithm based on focusing technique. The algorithm does not need any prior knowledge, and can accurately estimate the direction of arrival of wideband signals. After focusing and frequency domain smoothing, the following algorithm steps are basically the same as the narrowband signal DOA algorithm. Simulation results show that the algorithm is correct and effective. In view of the channel inconsistency which is often unavoidable in practical engineering environment, the influence of channel inconsistency on DOA algorithm is analyzed theoretically, and the influence is simulated by computer. The simulation results show that the amplitude error mainly affects the height of the spectral peak, while the phase error affects not only the height of the spectral peak, but also the position of the peak. Then, an effective channel calibration algorithm is proposed to solve this problem. Experiments show that the performance of the DOA algorithm after channel calibration is improved significantly.
【學(xué)位授予單位】：南京理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：TN911.23
，
本文編號(hào)：2248039
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