针对双基地嵌套多输入多输出雷达现有算法复杂度较高的问题,文中提出了一种基于泰勒展开离散傅里叶变换(DFT)的快速角度估计算法。该算法首先将匹配滤波输出转化为等效虚拟阵列接收信号的DFT空间谱,随后通过谱峰搜索得到波离方向(DOD)和波达方向(DOA)的初始角度估计,然后通过相位旋转技术在角度初始估计值附近搜索得到DOD和DOA的二次角度估计,最后根据虚拟阵列等效方向矩阵的一阶泰勒级数展开式对角度二次估计值进行误差修正,计算得到修正后的DOD和DOA的精确角度估计。与子空间算法相比,该算法避免了协方差矩阵计算和特征值分解,不仅提高了估计性能,而且显著降低了计算复杂度。仿真结果验证了所提算法的有效性和优越性。

Aiming at the problem of high complexity of existing algorithms in bistatic nested multiple input multiple output radar, a fast algorithm for angle estimation based on Taylor approximation discrete Fourier transform (DFT) is proposed. In this algorithm, the output matched filtering is firstly transformed to the DFT spatial spectrum of the signal received by the equivalent virtual array. Then the initial angle estimation of direction of departure (DOD) and direction of arrival(DOA) can be obtained by searching the peaks of DFT spectrum. Moreover, the fine estimation of DOD and DOA can be obtained by refine searching around the initial angle estimation with phase rotation technology. Finally, the fine angle estimation is revised to obtain the accurate DOD and DOA angle estimation from the first-order Taylor series expansion of equivalent direction matrix of virtual array. Compared with subspacebased algorithm, the proposed algorithm can avoid the calculation of covariance matrix and eigenvalue decomposition. Simulation results have verified the superiorities of the proposed algorithm in terms of computational complexity and estimation accuracy.

TN957.51