存在互耦误差时的圆台共形阵列DOA估计

DOA estimation for truncated cone conformal array in the presence of mutual coupling

阵列存在互耦误差时,由于理想导向矢量与实际导向矢量之间存在偏差,使得高分辨空间谱估计方法性能恶化.本文针对圆台共形阵列,充分利用其结构分布特性,以互耦矩阵呈复共轭对称分布为前提推导出了圆台共形阵列的互耦矩阵模型.在此基础上,利用两种模式对互耦矩阵进行分解,由此建立了两种基于圆台共形阵列的互耦误差自校正模型.两种模型均可以实现存在互耦误差时的圆台共形阵列DOA估计,且校正后的导向矢量与实际导向矢量之间的相关程度得到明显改善.另外,本文所提的互耦自校正方法具有较低的信噪比门限.理论分析和仿真结果证实了本文两种模型的有效性,可以为共形阵列的工程应用提供参考.

When mutual coupling error exists in the sensor array, the ideal steering vector differs from the actual steering vector, leading to degradation of the performance of some eigenstructure-based direction-finding methods. According to the truncated cone conforlnal array （TCCA） and on the premise of mutual coupling matrix （MCM） having a complex symmetric structure in this paper, we deduces the MCM model of TCCA by detailed analysis of its mutual coupling characteristics. We establish two models of mutual coupling error calibration, and realize the DOA estimation in the presence of mutual coupling by applying the multidimensional joint iteration method to these two models respectively. The correlation between the estimated steering vector and the actual steering vector becomes more closely, and these two proposed methods have an advantage of low signal-to-noise ratio （SNR） threshold. Theoretical analysis and extensive simulations verify the effectiveness of the proposed methods, and results of this paper can provide a reference for the engineering applications of conformal arrays.