任意波形相关性的机载MIMO雷达杂波建模与分析

摘要

This paper focuses on the effect of arbitrary transmitted waveform on clutter characteristics for airborne MIMO radar. Transmit waveform synthesis model is established by the transformation for signal space and sensor space. The uniform model of space time clutter is presented for airborne MIMO Radar, and the relation ship between signal waveform synthesis and the uniform model is expatiated. Clutter characteristics are analyzed in the simulations for arbitrary waveforms including coherent, correlated and orthogonal waveforms. It is found that the degree of clutter broaden is determined by the structure of signal cross-correlation matrix, and the clutter degree of freedom (DOF) is determined by the rank of the cross-correlation matrix. The uniform model is the foundation for the design of STAP algorithm.%为了分析任意发射波形相关性影响下的机载MIMO雷达杂波分布特性,从信号空间与阵元空间变换的数学角度构建了发射波形合成模型.在此基础上,提出了任意发射波形合成影响下的机载MIMO雷达杂波统一模型,论述了发射波形合成与杂波统一模型之间的关系.仿真揭示了统一模型下发射波形从全正交、相关到全相干的演变过程中杂波的分布特性.研究得出,发射波形互相关矩阵的结构决定了杂波谱展宽的程度,而该互相关矩阵的秩决定了杂波自由度大小.该模型为波形设计影响下的机载MIMO雷达STAP算法的设计提供了理论依据.