The coprime array owns a sparse array structure, which can effectively alleviate mutual coupling, while the holes existing in the difference co-array(DCA) greatly reduce the number of uniform degrees of freedom(uDOFs). In this letter, we propose a new coprime array structure called hole-free coprime array (HFCA) by carefully assembling the subarrays, and the resulting HFCA can generate a hole-free DCA. Furthermore, we derive the optimal HFCA that can produce the largest hole-free DCA with a given number of sensors, which contributes to an increase of uDOFs compared with existing coprime array structures. In addition, the simulations are provided to demonstrate the superiority of HFCA in terms of uDOFs, direction of arrival estimation performance, and spatial resolution.

中文翻译：

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用于 DOA 估计的无孔互质阵列：增强均匀协阵列

互素阵列具有稀疏阵列结构，可以有效缓解相互耦合，而差分协阵列（DCA）中存在的孔洞大大减少了统一自由度（uDOF）的数量。在这封信中，我们通过仔细组装子阵列提出了一种新的互素阵列结构，称为无孔互素阵列（HFCA），由此产生的 HFCA 可以生成无孔 DCA。此外，我们推导出了最佳 HFCA，它可以在给定数量的传感器下产生最大的无孔 DCA，与现有的互质阵列结构相比，这有助于增加 uDOF。此外，还提供了模拟以证明 HFCA 在 uDOF、到达方向估计性能和空间分辨率方面的优越性。