色噪声环境下单基地MIMO雷达分布式目标角度估计

Angle Estimation of Distributed Source for Monostatic MIMO Radar in Colored Noise

针对传统的二阶统计量角度估计算法在高斯色噪声环境下估计性能急剧下降甚至失效的问题,该文提出一种基于四阶累积量的单基地MIMO雷达相干分布式目标角度估计算法。首先建立单基地MIMO雷达的相干分布式目标信号模型,求取信号的四阶累积量矩阵;利用特征值分解分离出相互正交的信号子空间与噪声子空间,根据多重信号分类(MUSIC)算法原理,获得阵列的空间谱函数,通过谱峰搜索得到分布式目标的中心波达方向。该算法充分利用了四阶累积量对高斯过程的不敏感性,能够很好地抑制高斯色噪声对角度估计的影响。仿真结果证明了该算法的正确性和有效性。

An angle estimation algorithm based on fourth-order cumulants for distributed targets in monostatic Multiple Input Multiple Output （MIMO） radar is proposed in this paper, which could be used to deal with the problem of the performance declining in colored noise based on second order statics algorithm. At first, the signal model of coherent distributed targets is constructed, and then the fourth-order cumulants matrix can be calculated. Based on the eigen-decomposition, the signal subspace and the noise subspace, which are orthogonal, can be derived. Finally, according to the principle of the MUltiple SIgnal Classification （MUSIC）, the spectral function can be obtained, and with spectral peak searching, the central direction of arrival is estimated. The proposed algorithm makes full use of the property of fourth-order cumulants which ignores the Gaussian process to restrain the influence of the colored noise on estimating the angles. The computer simulation results demonstrate the correction and efficiency of the proposed method.