Robust Superdirective Frequency-Invariant Beamforming for Circular Sensor Arrays
Robust Superdirective Frequency-Invariant Beamforming for Circular Sensor Arrays
复制标题
用于圆形传感器阵列的鲁棒超定向频率不变波束形成
DOI：
10.1109/lsp.2017.2712151
复制
发表时间：
2017-08-01
影响因子：
3.9
通讯作者：
Li, Bing
中科院分区：
文献类型：
--
作者：
Wang, Yong;Yang, Yixin;Li, Bing
本文提出了一种用于圆形传感器阵列的鲁棒超指令频率不变波束形成方法。首先，利用圆阵列的特性将波束方向图精确地转换为等效形式，并对指向性因子和白噪声增益的表达式进行相应的修正。其次，基于以一般形式表示的所需超指示波束方向图的最小均方误差逼近，精确地推导出封闭形式的加权向量。当单元数足够大时，可以进一步简化权重向量，白噪声增益也被修改为简洁的形式，发现它是低频范围内单元数的递增函数。仿真和实验结果表明，该方法在给定适当的单元数的情况下，可以在较宽的频带内提供鲁棒的超指示不变频波束图，并且可以很容易地应用于实际中使用小型圆形传感器阵列处理宽带信号。
This letter proposes a robust superdirective frequency-invariant beamforming method for circular sensor arrays. First, the beampattern is accurately transformed into an equivalent form using the property of circular arrays, and the expressions of directivity factor and white noise gain are correspondingly modified. Second, a closed-form weighting vector is accurately derived based on the minimum mean square error approximation to a desired superdirective beampattern that is expressed in a general form. When the number of elements is sufficiently large, the weighting vector can be further simplified, and the white noise gain is also modified to a concise form that is found to be an increasing function of the number of elements in the low-frequency range. Simulations and experimental results show that this method can provide a robust superdirective frequency-invariant beampattern over a wide frequency band given a suitable number of elements, and it can be readily applied to process broadband signals in practice using small circular sensor arrays.