Research On Robust Beamforming Methods For MIMO Radar Based On Non-uniform Linear Arrays

Multiple input multiple output(MIMO)radar is a research hotspot in the field of radar,which has larger virtual aperture and better parameter accuracy than traditional phased array radar.Beamforming technology is one of the important research directions in array signal processing.Because the transmitter and receiver of MIMO radar system use array antenna arrangement,beamforming technology has become an important research content of MIMO radar.In the traditional MIMO radar beamforming algorithm,the uniform linear array(ULA)configuration is always adopted.However,the number of virtual elements generated by uniform linear array is limited.In recent years,the emerging non-uniform linear array(NLA)has more important significance in practical application.NLA can generate more virtual array elements and form larger virtual aperture.When the number of physical array elements is the same,NLA can provide higher beampattern solution and more number of target recognition.There are many kinds of NLA.This paper focuses on the study of Coprime array and Nested array.In this paper,NLA is introduced into the array configuration of MIMO radar,and the corresponding signal model is established.On this basis,the robust beamforming algorithm of MIMO Radar based on the NLA is studied deeply.The innovative research work of this paper is as follows:Firstly,based on the analysis of the existing robust Capon beamforming in array signal processing,NLA is introduced into the array element configuration,and two kinds of high-resolution beamforming algorithms with greater interference suppression ability named coprime array robust beamforming algorithm and nested array robust beamforming algorithm are implemented.Simulation results show that compared with the traditional ULA,these two methods can suppress more interference and greatly improve beampattern solution.Then,the robust beamforming method based on NLA for monostatic MIMO radar is investigated.An improved robust beamforming algorithm for monostatic MIMO radar which is the coprime between the transmitting array and receiving array is proposed by introducing the coprime array into the traditional signal model.Then,the nested array is introduced into the traditional signal model,and a robust beamforming algorithm for Monostatic MIMO radar which is the nested between the transmitting array and receiving array is proposed.Simulation results show that,compared with the existing algorithms,the proposed algorithm can not only improve the influence of angle error,but also greatly improve the number of interference suppression and beampattern solution.Finally,the robust beamforming method based on NLA for bistatic MIMO radar is studied.The coprime array and the nested array are introduced into the MIMO radar transmitting array and receiving array,and the corresponding signal models are established.The two robust high-resolution beamforming algorithms based on the coprime array and the nested array are proposed,respectively.The simulation results show that the two high-performance algorithms proposed in this paper can not only correct the angle error and achieve the purpose of robustness,but also greatly increase the beampattern solution and the number of interference suppression.They have better performance than traditional algorithms.