共查询到18条相似文献,搜索用时 125 毫秒
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共形阵列幅相误差校正快速算法 总被引:1,自引:0,他引:1
基于子空间的联合迭代算法可以实现对空间信源方位和阵列幅相误差参数的联合估计。当对共形阵列进行幅相误差校正时,由于其空域导向矢量不具有Vander monde结构,导致快速高分辨空间谱估计方法无法直接应用,而利用2维谱峰搜索实现空间方位估计的运算量较大,限制了算法在共形阵列上的应用。针对此问题,该文提出一种借助虚拟阵列实现共形阵列幅相误差校正的新方法。该方法利用虚拟阵列的特殊结构快速实现对信源的DOA估计,省去了谱峰搜索过程,因而运算复杂度低,便于工程实现。理论分析和仿真结果验证了所提算法的有效性,可为共形阵列的工程应用提供参考。 相似文献
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针对传统相干信号DOA估计算法在低信噪比、少快拍数以及阵列通道幅相误差下存在的角度分辨力差和测角性能不稳定问题,本文提出一种基于噪声空间加权重构的相干信号DOA估计算法。该算法首先利用共轭重构对阵列接收信号协方差矩阵作解相干处理;然后在信源大致方位内对导向矢量作定积分,计算积分矢量与整个噪声子空间正交基矢量的交空间基矢量,并以此对噪声子空间进行加权;最后运用加权重构后的噪声子空间建立算法空间谱函数,谱峰搜索估计得目标的DOA。计算机仿真结果表明,本文所提算法易实现低信噪比、少快拍数以及通道幅相误差下相干信号的DOA估计。 相似文献
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在运动阵列存在幅相误差和阵元位置未知的条件下,提出了一种基于子空间方法的阵列幅相误差校正和阵元位置估计方法。该方法要求一个方位已知的近场校正源。计算机仿真结果表明,该校正方法可有效地估计出阵列参数。 相似文献
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当阵列存在近场散射源时,互耦效应的分析和校正更加繁杂,这就导致了阵列互耦矩阵的参数化建模需要做进一步的扩展,使得互耦矩阵不再为方阵。然而现有的参数化互耦校正方法均假设互耦矩阵是一个具有特殊数学结构的方阵,对非方阵的互耦矩阵模型不适用。本文通过引入少量远离阵列且相互间隔较远的辅助阵元(互耦效应可以忽略)和方向未知的校正信源,提出了一种阵列天线散射条件下的互耦校正的参数估计算法。首先,推导了扩展后的非方阵互耦矩阵系数与方位依赖的幅相误差的等价关系;然后,对每次单源实验,得到校正源方位和各阵元方位依赖的幅相误差的联合估计,建立估计的幅相误差以非方阵互耦系数为参数的方程;最后,将多次单源校正得到的方程进行整合构建方程组,利用Tikhonov正则化方法求解不适定方程组实现互耦系数的有效估计,进而对阵列互耦进行校正。计算机仿真实验结果表明所提算法可以很好地解决阵列天线散射条件下的互耦校正问题,从而验证了算法的有效性。 相似文献
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针对导航应用中阵列天线导向矢量误差导致波束合成器性能恶化甚至失效的问题,提出了一种“北斗”信号重构的导向矢量实时校正算法。该算法利用重构的本地“北斗”参考信号与阵列天线接收信号进行相关解扩处理,然后利用信号子空间与信号正交补空间正交的特性,构造代价函数对各卫星方向的阵列导向矢量进行校正。仿真结果表明,经过校正的导向矢量相位误差从-100°~100°降低到-10°~10°范围内,幅度误差从-10~10 dB降低到-4~2 dB范围内;另外,导向矢量校正后,卫星信号波达方向估计误差在0.2°以内,估计精度大大提高。 相似文献
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一种利用互耦矩阵稀疏性的阵列误差有源校正改进算法 总被引:1,自引:0,他引:1
重点研究了波达方向估计中由阵元互耦、幅相误差以及阵元位置误差的综合影响引起的阵列误差校正问题,其主要方法是通过矩阵特征分解得到一组校正源的方向矢量来估计阵列误差.文中给出了一种改进的参数估计算法,该算法充分利用了互耦矩阵的稀疏性,并通过交替迭代的方法实现了阵列误差矩阵和阵元位置误差的优化校正.计算机仿真结果表明文中的改进算法提高了参数估计精度. 相似文献
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Junli Liang Ding Liu 《Signal Processing, IEEE Transactions on》2010,58(1):108-120
Passive source localization is one of the issues in array signal processing fields. In some practical applications, the signals received by an array are the mixture of near-field and far-field sources, such as speaker localization using microphone arrays and guidance (homing) systems. To localize mixed near-field and far-field sources, this paper develops a two-stage MUSIC algorithm using cumulant. The key points of this paper are: (i) in the first stage, this paper derives one special cumulant matrix, in which the virtual ?steering vector? is the function of the common electric angle in both near-field and far-field signal models so that source direction-of-arrival (DOA) (near-field or far-field one) can be obtained from this electric angle using the conventional high-resolution MUSIC algorithm; (ii) in the second stage, this paper derives another particular cumulant matrix, in which the virtual ?steering matrix? has full column rank no matter whether the received signals are multiple near-field sources or multiple far-field ones or their mixture. What is more important, the virtual ?steering vector? can be separated into two parts, in which the first one is the function of the common electric angle in both signal models, whereas the second part is the function of the electric angle that exists only in near-field signal model. Furthermore, by substituting the common electric angle estimated in the first stage into one special Hermitian matrix formed from another MUSIC spectral function, the range of near-field sources can be obtained from the eigenvector of the Hermitian matrix. The resultant algorithm avoids two- dimensional search and pairing parameters; in addition, it avoids the estimation failure problem and alleviates aperture loss. Simulation results are presented to validate the performance of the proposed method. 相似文献
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针对近场信号源,本文基于对称子阵列提出了两种稀疏信号表示的目标定位方法。首先利用对称阵元导向矢量的关系分离出时延中的方向角和距离两个参数,将一个近场目标定位问题转换为一个类远场的方向角估计问题,再通过稀疏信号重构的方法分步得到方向角和距离两个参数的估计。在参数分离的过程中,方法二通过构造共轭部分,所得到的虚拟远场阵列阵元数等效于原始阵列,故所能估计的信源数约为方法一的两倍。和同类方法相比,本文提出的方法具有较低的计算量。仿真表明,本文两种方法具有更高的分辨率。 相似文献
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In this paper, we consider the manifold separation technique (MST), which stems from the wavefield modeling formalism developed for array processing. MST is a method for modeling the steering vector of antenna arrays of practical interest with arbitrary 2-D or 3-D geometry. It is the product of a sampling matrix (dependent on the antenna array only) and a Vandermonde structured coefficients vector depending on the wavefield only. This allows fast direction-of-arrival (DoA) algorithms designed for linear arrays to be used on arrays with arbitrary configuration. In real-world applications, the calibration measurements used to determine the sampling matrix are corrupted by noise. This impairs the performance of MST-based algorithms. In particular, we study the effect of noisy calibration measurements on subspace-based DoA algorithms using MST. Expressions describing the error in the DoA estimates due to calibration noise and truncation are derived. This allows predicting the performance of MST-based algorithms in real-world applications. The analysis is verified by simulations. We established a link between the optimal number of selected modes and the statistics of calibration noise. We analyze the modeling error when MST is used for 1-D (azimuth) DoA estimation. 相似文献