共查询到18条相似文献,搜索用时 109 毫秒
1.
2.
3.
针对均匀圆阵互耦自校正问题,提出了一种基于旋转不变参数估计(ES-PRIT)技术的互耦自校正算法。通过模式空间转换技术将互耦影响下的均匀圆阵流型向量近似等效为存在幅相误差的虚拟均匀线阵流型向量,并且该幅相误差矩阵满足中心对称性。利用该性质并结合ESPRIT技术分别给出了信源方位和互耦向量的闭式解。为了减少模式空间转换偏差的影响,基于Belloni方法,给出了一种互耦影响下抵消模式空间转换偏差的方法。仿真实验验证了新算法的有效性。 相似文献
4.
5.
该文研究多子阵(multiple subarrays)阵元互耦条件下的波达方向(DOA)估计,假设阵列由多个位置已知的均匀线阵(ULA)组成,但线阵阵元间存在互耦效应。利用均匀线阵互耦矩阵的带状、对称Toeplitz性及多子阵互耦矩阵的块状对角特性,提出了一种解耦合波达方向估计及互耦自校正算法。该算法在未知阵元互耦参数的情况下,可准确估计出信源的波达方向。另外,算法在精确估计波达方向的同时,还可准确估计出阵元问的互耦系数,实现多子阵的互耦自校正。算法的波达方向估计只需一维谱峰搜索,避免了通常多参数联合估计的多维非线性搜索及迭代运算,可明显减小算法运算量。文中讨论了算法参数可辨识性的必要条件,并分析计算了多参数联合估计的克拉美-罗界(CRB)。理论分析及蒙特卡罗仿真结果表明,该算法具有计算量小、DOA估计分辨力高、互耦校正效果好等优点。 相似文献
6.
多子阵互耦条件下的一维波达方向估计及互耦自校正 总被引:1,自引:0,他引:1
该文研究多子阵(multiple subarrays)阵元互耦条件下的波达方向(DOA)估计,假设阵列由多个位置已知的均匀线阵(ULA)组成,但线阵阵元间存在互耦效应。利用均匀线阵互耦矩阵的带状、对称Toeplitz性及多子阵互耦矩阵的块状对角特性,提出了一种解耦合波达方向估计及互耦自校正算法。该算法在未知阵元互耦参数的情况下,可准确估计出信源的波达方向。另外,算法在精确估计波达方向的同时,还可准确估计出阵元间的互耦系数,实现多子阵的互耦自校正。算法的波达方向估计只需一维谱峰搜索,避免了通常多参数联合估计的多维非线性搜索及迭代运算,可明显减小算法运算量。文中讨论了算法参数可辨识性的必要条件,并分析计算了多参数联合估计的克拉美-罗界(CRB)。理论分析及蒙特卡罗仿真结果表明,该算法具有计算量小、DOA估计分辨力高、互耦校正效果好等优点。 相似文献
7.
8.
9.
在高斯噪声背景下,针对互耦条件下的均匀线阵(Uniform Linear Array, ULA),该文提出了一种联合多用户波达方向(Direction Of Arrival, DOA)估计与互耦误差自校正算法。该算法首先利用特征矩阵联合相似对角化(Joint Approximative Diagonalization of Eigen matrix, JADE)方法估计出各用户广义空间特征矢量,然后定义了一个将各用户广义空间特征矢量转换为只与部分阵元相关的转换矩阵,进而在斜投影及前后向空间平滑的基础上,实现了多用户相干信源DOA估计,最后以多用户相干信源DOA及广义空间特征矢量估计值为基础,给出一种互耦自校正方法。仿真结果表明:该算法具有较高的DOA估计精度及DOA估计成功率,而且对高斯白噪声/色噪声背景,阵列互耦误差已知/未知情形,均具有普适性。 相似文献
10.
提出了基于协方差匹配技术的均匀线阵互耦和幅相误差联合校正算法.首先,根据协方差匹配技术中的目标函数和均匀线阵的误差模型,设计了一种交替迭代算法用以实现各种参数的优化计算.接着,为了避免该算法中的每轮循环迭代都需要进行波达方向估计这一复杂环节,利用理想条件均匀线阵协方差阵的Toeplitz性,给出了另一种改进型交替迭代算法用以减少计算复杂度.与基于子空间技术的阵列误差校正方法相比,文中的两种新算法可直接利用信源的统计特性,并且适用于不同的高斯噪声模型(例如噪声功率不一致),仿真实验验证了新算法的有效性和优越性. 相似文献
11.
阵列信号在实际应用中,常常会面临噪声的干扰,低信噪比(signal noise ratio, SNR)时波束形成器性能会急剧下降.针对该问题,提出一种基于改进互耦系数估计的抗互耦算法的自适应波束形成,即研究信号在不同输入SNR以及不同干扰波达方向(direction of arrival,DOA)估计误差下的互耦系数估计误差;并通过误差分析修正原算法不同SNR下参与估计信号的数目.改进算法改进了导向矢量和期望信号,提高了低SNR下互耦系数估计的准确度,对比分析验证了其在低SNR情况下有更强的抗干扰能力,对互耦现象有着更好的稳健性. 相似文献
12.
阵元间互耦会严重影响阵列的测向性能。文章基于子空间类测向方法,在远场情况下,提出了一种新的阵元互耦有源校正算法。文中的算法是以迭代的形式给出,其目标函数建立在信号子空间性质的基础上,并且适用于多个校正源同时存在的情况。计算机仿真验证了它的有效性,而且可推广至校正源方位估计存在偏差的情况。 相似文献
13.
互耦条件下均匀线阵DOA盲估计 总被引:6,自引:1,他引:5
阵元间存在互耦时,经典的波达角(DOA)估计算法性能急剧下降甚至失效。针对互耦条件下均匀线阵DOA估计问题,该文提出一种基于盲源分离的DOA盲估计算法。首先,利用源信号的统计特性,由盲源分离方法估计广义阵列流形矩阵;然后,利用均匀线阵互耦矩阵带状、Toeplitz矩阵的特点,将DOA估计问题转化为多个可分离非线性最小二乘问题,由多个1维频域搜索得到DOA的估计。该算法无需高维搜索或多维迭代,对互耦自由度要求更低,互耦自由度未知时仍旧适用,稳健度高。数值仿真验证了该文算法的有效性。 相似文献
14.
阵元间存在互耦时,会对阵列流型产生扰动,同时当空间来波存在相干信源时,协方差矩阵会产生秩亏,这两类问题都会使子空间类估计算法性能急剧下降甚至失效。针对互耦效应下的解相干问题,该文提出了一种仅利用阵列单快拍即可实现完全解相干和解互耦算法互耦效应下的修正单次快拍算法(MC-ENDTOP)。该方法将原单快拍算法应用背景推广至任意形式来波信号,利用一次快拍构造等效接收数据协方差矩阵,通过数据分解,将互耦系数从阵列流型矩阵中剥离,从而实现了完全解互耦,并将其归入分解后的等效信号协方差矩阵中,由于等效信号协方差矩阵为对角阵,且对角元素与信号相关性无关,因此进一步实现了完全解相干。仿真验证了该文算法能够抑制互耦影响,估计性能和无互耦时相当,且适用于实时性要求高的场合。 相似文献
15.
Directional biases are shown to exist for a four-element square CODAR receiving array used for coastal current mapping. The sources being sidelobes and mutual coupling (a type of pattern distortion), these nonstatistical biases depend both on the geometry/size of the square array as well as the particular closed-form algorithm employed to estimate bearing. Typical rms errors due to these sources lie between 5-15°. Reconfiguration of the four-element antenna geometry may reduce sidelobe biases when closed-form algorithms are employed, but only at the expense of increased mutual-coupling bias. A least-squares algorithm is given that corrects for pattern distortion, circumventing this shortcoming of closed-form methods; this algorithm can also improve sidelobe biases. Other antenna systems possessing no sidelobes are in use for CODAR that eliminate these sources of error. 相似文献
16.
Zhongfu Ye Chao Liu 《Antennas and Propagation, IEEE Transactions on》2008,56(2):371-380
Many classical direction of arrival (DOA) estimation algorithms suffer from sensitivity to sensor coupling. By applying a group of auxiliary sensors in a uniform linear array (ULA), we prove the resiliency of the MUSIC direction finding algorithm against array sensor coupling. We show that the performance of MUSIC algorithm under antenna array with unknown coupling can be very close to the case with known coupling. We can also estimate the mutual coupling coefficients before refining the DOA estimates by utilizing an extended sensor array. Moreover, our analysis on the effect of mutual coupling in direction finding illustrates the existence of some blind angles which should be avoided when the array is designed. Our simulation results corroborate our analysis. 相似文献
17.
This paper investigates the benefit of mutual coupling compensation via a method of moments (MoM) approach in a uniform circular antenna array operating at 1.8 GHz. This mutual coupling compensation technique is applied to a direction of arrival (DOA) study of up to two cochannel mobile users. Field measurements and computer simulations are examined to explore the assumptions of the technique and verify its effect when using the Bartlett and MUSIC DOA algorithms. Computer simulations considering the application of the technique to down-link beamforming are also included. Experimental results show that the mutual coupling compensation technique improves up-link DOA algorithm performance primarily by reducing unwanted sidelobe levels. This reduction in sidelobe levels aids in down-link beamforming weight design. Specifically, simulation results show that use of the compensation technique allows DOA-based down-link beamforming algorithms to perform similarly to spatial signature-based algorithms. All field measurements were made using the smart antenna testbed at the University of Texas at Austin 相似文献
18.
Fabrizio Sellone Alberto Serra 《Signal Processing, IEEE Transactions on》2007,55(2):560-573
In this paper, a novel online mutual coupling compensation algorithm especially tailored to uniform and linear arrays is presented. It is conceived to simultaneously compensate for mutual coupling and estimate the direction-of-arrivals (DOAs) of signals impinging on the array since the estimated calibration matrix can be embedded within any classical super-resolution direction-finding method. An alternating minimization procedure based on closed-form solutions is performed to estimate the mutual coupling matrix in the field of complex symmetric Toeplitz matrices. Unlike many existing array calibration methods, it requires neither the presence of calibration sources nor previous calibration information as initialization. Computer simulations show the effectiveness of the proposed technique and prove that the nice statistical properties of classical super-resolution DOA estimation algorithms can be restored despite the presence of mutual coupling 相似文献