一种优化嵌套MIMO的无孔差合阵列设计

针对现有嵌套MIMO阵列自由度有限的问题，提出一种基于优化嵌套阵的优化改进方案。其不止保留了嵌套MIMO阵列设计的原有优势，具有阵元位置以及自由度的闭合表达式，而且极大程度地提高了阵列孔径以及自由度。优化嵌套MIMO阵列设计首先将优化嵌套阵作为发射和接收阵，其次对MIMO阵列的合阵进行做差处理，得到阵元位置的差合阵列。通过合理的设计发射和接收阵的阵元间距，可以获得一个无孔的差合阵列。当阵元总数给定的时候，通过分析阵列结构的特点，可以得到发射和接收阵的最佳阵元数目。仿真实验表明，与嵌套MIMO阵列设计相比，所提方法在不增加实际阵元数目的情况下可以有效扩展阵列孔径，增加自由度，从而提高MIMO雷达波达方向估计精度。

An Optimized Nested MIMO Array with Hole-Free Difference Array

Aimed at the problems that the degree of freedom in the current nested MIMO array (Multiple-Input Multiple-Input Multiple Output Multiple Array) is limited, an optimized nested array is proposed, i.e. to optimize the nested MIMO array design. This method not only retains the original advantage of nested MIMO array design-closed expression with array element position and degree of freedom, but also greatly improves the array aperture and degree of freedom (DOF). Firstly, the optimized nested array is used as the transmitting and receiving arrays, and then the difference between the MIMO arrays is processed to obtain the difference array of array elements. By properly designing the array spacing of the transmitting and receiving arrays, a non-porous difference matrix can be obtained. When the total number of array elements is given, by analyzing the characteristics of the array structure, the best array element number of the transmitting and receiving arrays can be obtained. The simulation experiments show that compared with the nested MIMO array design, the proposed method can effectively expand the array aperture, increase the degree of freedom, and increase the DOA estimation accuracy of the MIMO radar under condition of non increasing the number of actual array elements.