中文摘要：

针对发射波形正交性退化影响机载多输入多输出（multiple-input multiple-output,MIMO）雷达的杂波特性,基于信号空间和子阵空间的变换原理,建立了波形正交性退化下的机载MIMO雷达杂波通用模型和标准模型。基于带限信号的最优逼近特性,分析了波形正交性退化下的空时等效阵列孔径变化规律,提出了杂波自由度（degree of freedom,DOF）的估计准则。最后,仿真验证了杂波模型及杂波自由度估计准则的有效性。

英文摘要：

Aiming at the clutter characteristics of airborne multiple-input multiple-output（MIMO） radar under the orthogonal degradation of waveform,the general and standard clutter models of airborne MIMO radar are presented under the orthogonal degradation of waveform based on the transformed principle of subarray space and transmit signal space.Then the regularity of change for space-time equivalence aperture is analyzed under the orthogonal degradation of waveform based on the optimum approached property of the band-limit signal,and an estimation rule for the degree of freedom（DOF） of clutter is presented.Finally,simulation results show the effectivity of the proposed models and rules.