二维混合MIMO相控阵雷达的嵌套阵列结构设计

Nested array structure design of two dimensional hybrid MIMO phased radar

针对二维混合多输入多输出(multiple input multiple output,MIMO)相控阵雷达发射阵列子阵分割带来的自由度(degree of freedom,DOF)减小问题,提出了基于嵌套阵结构的收发阵列设计方法。首先给出基于一维嵌套阵的二维混合MIMO相控阵雷达发射阵列,在此基础上将接收端设置为嵌套阵,最后通过做虚拟阵列以及差异阵列,形成虚拟阵元数目扩展,在保留混合MIMO相控阵雷达优势的基础上增大了阵列DOF。同时给出了阵列流形的闭合表达式,推导出了基于最大DOF准则的最优嵌套阵元数目。仿真实验表明,相较于传统和互质的混合MIMO相控阵雷达,所提方法可有效提高阵列DOF和波达方向估计精度。

In order to reduce the loss of degree of freedom (DOF) brought by the transmit sub-array splitting of two dimensional hybrid multiple input multiple output (MIMO) phased radar, this paper presents a design method of transmitting and receiving array based on the nested array structure. Firstly, a two dimensional hybrid MIMO phased radar transmitting array based on the one dimensional nested array is presented. On this basis, the receiving end is set as a nested array, and finally a virtual array and difference coarray are formed to expand the number of virtual array elements. The expansion increases the DOF of arrays while preserving the advantages of hybrid MIMO phased radars. At the same time, the closed-form expressions of array manifolds are also given. Based on the maximum DOF criterion, the optimal number of nested array elements at the transceiver is deduced. Simulation experiments show that compared with the traditional and coprime hybrid MIMO phased radar, the proposed method can effectively improve the array DOF and direction of arrival estimation accuracy.