多径条件下米波OFDM-MIMO雷达波束性能及特性分析

针对米波正交频分多路复用-多输入多输出(Orthogonal Frequency Division Multiplexing-Multiple Input Multiple Output, OFDM-MIMO)雷达波束形成问题,建立了米波条件下频分复用MIMO雷达阵列信号模型,理论导出了该体制下多径特性定量分析的理论框架、直达波和多径回波模型及其联合发射-接收双程方向图增益闭合表达式。提出了利用米波OFDM-MIMO雷达阵列双程方向图具有距离-角度二维分辨能力抑制多径算法。所提方法能够有效抑制阵列法线方向多径回波,同时有效抑制输出信干噪比周期性损失,且随频偏带宽的增大抑制能力进一步提升。

Multipath scenario beam performance and characteristics analysis for meter-wave OFDM-MIMO radar

In order to solve the beamforming problem of meter-wave OFDM-MIMO (orthogonal frequency division multiplexing-multiple input multiple output) radar, a signal model of frequency division multiplexed MIMO radar array under meter-wave conditions was established, and a theoretical framework for quantitative analysis of multipath characteristics of this system was derived theoretically. The direct-wave and multipath echo models, as well as the closed-form expression of the gain of the joint transmitter-receive bi-directional pattern were derived. A multipath suppression algorithm with range-angle two-dimensional resolution based on the bi-path pattern of a meter-wave OFDM-MIMO radar array was proposed. The proposed method can effectively suppress the multipath echo in the normal direction of the array, and also effectively suppress the periodic loss of the output fresh dryness ratio, and the inhibition ability is further improved with the increase of the frequency offset bandwidth.