基于双频互质阵列的DOA估计方法

DOA estimation based on dual-frequency co-prime array

针对互质阵列单频工作模式下,舍弃差协同阵中非均匀虚拟阵元引起的DOA估计最大可分辨信号源数目损失的问题,提出了一种利用双频工作模式提升互质阵列DOA估计最大可分辨信号源数目的方法,通过选择单个合适的额外工作频率获取额外不同位置的差协同阵虚拟阵元,进而填充参考工作频率下互质阵列差协同阵中两个缺失的虚拟阵元。相比于单频工作模式,双频工作模式获取了更多均匀分布的虚拟阵元,DOA估计的自由度得到了提升,实现了对更多非相干信号源的DOA估计。具体来讲,对于具有N+2M-1个物理阵元的互质阵列,双频工作获得的自由度提升为M,对可实现DOA估计的非相干信源数目的增加为M。

Under the condition of single-frequency operation for co-prime array,discarding the non-uniform virtual elements in the difference co-array brings about the number loss of the resolvable sources in DOA estimation. This paper proposed a DOA estimation algorithm to improve the number of the resolvable sources based on the co-prime array with dual-frequency operation. By selecting single proper additional operation frequency,it obtained the additional different positions of virtual elements in the difference co-array to fill two missed virtual elements in the difference co-array of co-prime array with the reference operation frequency. Compared with the single-frequency operation,the proposed dual-frequency operation acquired more uniform virtual elements,improving the degree-of-freedom of DOA estimation which resulted in the DOA estimation for more incoherent sources. More specifically,corresponding to a co-prime array with N + 2M-1 physical elements,the dual-frequency operation improves the degree-of-freedom by M and increases the number of resolvable incoherent sources in DOA estimation by M.