针对共形阵列天线的宽带独立信源方位估计问题,给出了一种信源方位与极化参数的联合估计算法.首先通过短时傅里叶变换(STFT),将宽带信号划分为多个窄子带信号,然后延时接收信号,构造满足旋转变换关系的成对快拍数据,从而估计出不同子带的信号流型矩阵.在此基础上,利用各子带间的频率差异性,实现信源方位与极化参数的联合估计.所提算法适用于任意共形载体,无需参数搜索和配对,可完成二维波达方向和极化参数的联合估计,极大地降低了估计算法复杂度,具有较强的普适性与工程实现价值.计算机仿真实验验证了算法的有效性.
Taking into account the direction of arrival(DOA)of wideband signals for conformal array antenna,ajoint DOA and polarization estimation algorithm was proposed.First,the narrow sub-band was acquired by using the short time Fourier transformation(STFT).Then,two sets of snapshots which satisfied rotation invariance were construsted via time-delayed signal.So the array steering matrices corresponding respectively to different narrow sub-bands were estimated.Furthermore,making use of the frequency difference of different narrow sub-bands,the 2D DOA and polarization estimation were acquired jointly.The proposed method can be applied to arbitrary conformal array structure without parameter matching and searching process.The algorithm can also reduce the computational complexity considerably and can efficiently improve the practical engineering value.Monte-Carlo simulation demonstrates the good performance and the effectiveness of the proposed method.