相干信号来波方向估计技术研究
发布时间：2018-09-18 13:18
【摘要】：来波方向估计技术,也就是DOA估计技术由于其精确的角度估计特点,被广泛地应用在卫星、通信、探测等多个方面。本文在简单的总结了传统的经典DOA估计算法之后,针对相干信号条件下的DOA估计问题,DOA算法快速化问题以及宽带信号条件下的稳健DOA估计问题分别进行了研究,同时也对通道不一致性对DOA估计问题的影响以及解决办法进行了研究。本文主要工作如下：1.首先,给出了阵列信号处理的基本模型。简单地介绍了传统的经典MUSIC算法以及ESPRIT算法的基本原理,给出了具体的推导过程,分析了算法的各自特点。之后,给出具体的仿真参数,对算法进行了仿真,并分析了具体场合下,算法的角度分辨力随输入SINR之间的关系。2.针对相干信号条件下,传统的DOA估计算法失效的问题,提出了若干解决方案。第一,利用Toeplitze技术将相干信号条件下得到的阵列接收信号协方差矩阵进行Toeplitze化,然后将重新得到的新协方差矩阵应用到传统DOA算法中,能够在信号相干条件下,得到正确的来波方向估计值。第二,利用虚拟空间平滑技术,通过虚拟化阵元数目,实现信号的解相干,进而完成DOA估计。计算机仿真验证了上述算法的正确性和有效性。3.针对传统DOA算法需要进行谱峰搜索以及特征分解,从而导致运算量特别大的问题,提出了基于GS正交化的DOA估计以及基于MSWF的DOA估计算法。上述算法以获取近似的信号子空间为目的,在适当的牺牲子空间估计精度的情况下,极大的减少了的运行时间,降低了算法的复杂度。通过计算机仿真将上述方法和传统DOA方法进行了比较,可以看出,程序运行时间在很大程度上减少了。此类算法对实际工程应用具有一定的指导意义。4.针对宽带信号DOA中的色散问题,在系统总结了前人基于聚焦技术的DOA算法之后,提出了基于全局聚焦的稳健DOA算法。该算法不需要任何先验知识,能够准确地估计出宽带信号的来波方向信息,并且再经过聚焦和频域平滑处理之后,后续的算法步骤和窄带信号DOA算法基本相同。仿真实验验证了该算法的正确性和有效性。5.针对实际工程环境中往往不可避免的通道不一致性问题,首先理论分析了通道不一致性给DOA算法带来的影响,并通过计算机对该影响进行了仿真。仿真表明幅度误差主要影响谱峰的高度,而相位误差不仅影响谱峰的高度,还同时影响谱峰的位置。之后,针对这个问题,提出了一种有效的通道校准算法。实验表明,经过通道校准后的DOA算法在性能上存在显著的提升。
[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.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN911.23
，
本文编号：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.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN911.23
，
本文编号：2248039
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