三正交分离式极化敏感阵列的波达方向估计

摘要

This paper discusses the issue of multiple targets’ Direction Of Arrival (DOA) estimation for Spatially Spread Polarization Sensitive Array (SS-PSA). First, the signal model of sparsely uniform SS-PSA with three orthogonally oriented polarized-antenna is presented. Then the rotational invariance of the proposed uniform array is utilized to calculate the ambiguous DOA estimation by means of ESPRIT method. The spatial phase shift raised by spatially spread polarized-antenna is compensated by the ambiguous DOA estimation to obtain virtual collocated polarized-antenna. The corresponding virtual DOA estimation is calculated by the multi-dimensional angle structure among the virtual collocated polarized-antenna. Finally, the multiple targets’ DOA estimation is obtained by extracting the minimum norm of the difference between the ambiguous DOA estimation and the corresponding virtual DOA estimation. The proposed array can reduce the array mutual coupling by using the spatially spread polarized-antenna instead of conventional collocated polarized-antenna. Moreover, the DOA estimation accuracy can be improved greatly because of the extended aperture offered by the sparse array. Computer simulation results verify the effectiveness and high-accuracy of the proposed SS-PSA DOA estimation algorithm.%该文研究了分离式极化敏感阵列(SS-PSA)的多目标波达方向(DOA)估计问题。首先建立三正交分离式极化敏感均匀稀疏阵列的信号模型；接着利用阵列的旋转不变性采用ESPRIT算法计算出多值模糊DOA估计；利用该模糊DOA估计值对分离式极化天线进行空间相移的补偿，然后利用共点式极化天线之间的多维角度结构求出对应的虚拟DOA估计；最后通过提取多值模糊估计值和对应虚拟估计值之差的最小范数得到多目标的DOA估计。该文所提阵列采用分离式极化天线代替传统共点式极化天线，降低了阵列的互耦影响；采用稀疏阵列结构有效地扩展了阵列的物理孔径，大大提高了DOA估计精度。计算机仿真结果证明了该算法对分离式极化天线DOA估计的有效性和高精度性。