基于插值拟合的抛面共形阵盲极化DOA估计

Blind polarization DOA estimation of parabolic conformal array based on interpolation fitting

共形阵的载体曲率形式复杂,导致抛面共形阵的方向图指向不同,而且不同天线单元的极化特性迥异。常见的圆柱阵、圆锥阵在同一母线上的极化分量是相同的,但是抛面共形阵的载体曲率是变化的,因此抛面共形阵的参数估计问题需要考虑极化分量的影响,导致无法直接用同一母线上阵元回波数据结合免搜索算法获得目标二维波达方向(direction of arrival,DOA)估计。首先,提出一种通过插值拟合思想将抛面共形阵带有极化参数的阵列流形拟合成无极化参数的阵列流形,然后合理选择子阵对,再利用旋转不变技术估计信号参数(estimation of signal parameters via rotational invariance techniques,ESPRIT)方法实现盲极化的DOA估计,同时给出了经过插值拟合后的克拉美罗边界(Cramer-Rao bound,CRB)。最后仿真验证了方法的有效性。

The carrier curvature of the conformal array is complex,which leads to the variation of the pattern gains and the polarization characteristics of conformal array.The polarization components of common cylindrical arrays and conical arrays on the same generatrix are the same,but the curvature of the carrier of parabolic conformal arrays is variable.Therefore,the parameter estimation problem of parabolic conformal arrays needs to consider the influence of polarization components.As a result,it is impossible to directly obtain the two-dimensional direction of arrival(DOA)estimation for the target by the search-free algorithm.Firstly,a method of fitting the parabolic conformal array with polarization parameters to an array manifold with no polarization parameters through the idea of interpolation fitting is proposed.Then,the estimation of signal parameter via rotational invariance techniques(ESPRIT)method is used after reasonable selection of sub-array pairs for realizing blind polarization DOA estimation.At the same time,the Cramer-Rao bound(CRB)value is given after interpolation fitting.Finally,the simulation verifies the effectiveness of the method.