Nowadays, sparse arrays have been a focus for direction-of-arrival (DOA). The existing arrays can achieve high degree of freedom (DOF) bigger than the number of sensors when using the spatial smoothing methods. However, the small inter-element spacing degrades the DOA estimation accuracy when facing severe mutual coupling. In order to alleviate mutual coupling, a coprime linear array using three uniform linear arrays (CLA-U3) is proposed. The expression of sensor locations is given, and the analysis of DOF is considered. The minimum subarray inter-element spacing in CLA-U3 is bigger than that of the existing arrays, which means that CLA-U3 can be less sensitive to mutual coupling. Moreover, the difference co-subarrays can fill each other's holes, so CLA-U3 and other sparse arrays composed of three subarrays have close DOF. Simulation experiments prove the favourable performance of DOA estimation.

中文翻译：

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考虑互耦合的三个均匀线阵互素线阵到达方向估计

如今，稀疏阵列已成为到达方向（DOA）的焦点。当使用空间平滑方法时，现有阵列可以实现大于传感器数量的高自由度（DOF）。然而，当面临严重的相互耦合时，较小的阵元间距会降低 DOA 估计的精度。为了减轻相互耦合，提出了使用三个均匀线性阵列的互质线性阵列（CLA-U3）。给出了传感器位置的表达式，并考虑了自由度的分析。 CLA-U3 中的最小子阵列元件间间距大于现有阵列的最小子阵列元件间间距，这意味着 CLA-U3 对相互耦合的敏感度较低。而且，不同的共子阵可以互相填补空洞，因此CLA-U3等由三个子阵组成的稀疏阵具有接近的自由度。仿真实验证明了DOA估计的良好性能。