非均匀线阵的互耦自校正

针对非均匀线阵(non-uniform linear array,NULA)互耦问题进行了研究。与均匀线阵(uniform linear array,ULA)不同的是,NULA的互耦矩阵并不具有带状对称Toeplitz的特性,因而处理起来更为复杂。首先,根据阵列结构的特点,可将其互耦矩阵转换为两个具有Toeplitz特性矩阵相减的形式,从而方便实现角度和互耦系数的解耦合。而后结合子空间原理,同时估计信号的波达方向(direction of arrival, DOA)和互耦系数。算法无需额外的校正源,也不需要非线性的高维搜索和迭代过程,计算量小。仿真结果表明,所提算法能够很好地估计出信号角度和互耦误差系数,具有精度高、分辨力强的特点,可以有效地解决此类NULA的互耦问题。

Self-calibration of mutual coupling for non-uniform linear array

The mutual coupling problem of non-uniform linear array (NULA) is studied. Unlike uniform linear array (ULA), the mutual coupling matrix of NULA does not have the characteristics of banded symmetric Toeplitz, so it is more complex to deal with. First of all, according to the characteristics of the array structure, the mutual coupling matrix is transformed into the form of two ‘Toeplitz’ matrix subtractions. Thus, it is convenient to realize the decoupling of the angle and the mutual coupling coefficients. And then combining with the subspace principle, the direction of arrival (DOA) and the mutual coupling coefficient are estimated simultaneously. The algorithm does not require additional auxiliary correction source, and also it does not need non-linear high-dimensional search and iterative process, so the computation is small. Simulation results show that the proposed algorithm can estimate the signal angle and the mutual error coefficient well, which has the characteristics of high precision and strong resolution, hence, it can effectively solve the mutual coupling problem of the NULA.