Research On Interference Suppression Based On Frequency-Controlled Array Beamforming

The system model of target Angle and distance correlation is constructed by transmitting signals in each array with small frequency offset.In order to solve the range and Angle coupling characteristics of frequency-controlled array radar,form energy-gathered spot beam,and improve the anti-jamming ability of frequency-controlled array radar,this paper starts from the basic characteristics of uniform linear frequency array,extends to uniform circular array,and focuses on the study of spot beamforming and interference suppression methods.Firstly,based on the basic theory of array signal processing and frequency-controlled array beam characteristics,nonlinear frequency offset,multi-carrier array method and adaptive beamforming method are used in uniform linear array and nonlinear frequency offset and adaptive beamforming method is used in uniform circular array.The range and Angle coupling characteristics of frequency array are solved,so that the frequency array emission pattern can form energy concentrated spot beam at the target position.Secondly,the most common multi-antenna receiving array of linear frequency array is discussed,and two different receiving modes of unified receiving and separated receiving are compared.Then the adaptive beamforming method for Minimum Variance distortion-free Response(MVDR)was used to suppress the interference based on the point beam energy accumulation.Based on the independent analysis of the high side lobe energy of Angle and distance dimension,an improved convex Optimization method of the Worst-Case Performance Optimization algorithm(WCP)is proposed.The optimal solution of the weight vector is obtained through the convex optimization theory.Can form spot beamforming pattern while reducing sidelobe energy and interference suppression.In the independent analysis of two-dimensional Angle dimension and distance dimension,it has lower sidelobe energy,deeper zero trap,better interference suppression effect and better performance.Finally,in view of the need of 3D beam control in practical engineering applications,the uniform linear frequency array is extended to uniform circular array.The single antenna receiving model of uniform circular array has one more elevation dimension,so the degree of freedom of the array is improved.On this basis,interference suppression is studied.The improved convex optimization algorithm is applied to the uniform circular array.Based on the target position point beamforming,better interference suppression performance can be obtained than MVDR algorithm,and the general adaptation of the improved convex optimization algorithm is verified.Then the Quantum Particle Swarm Optimization(QPSO)algorithm is applied to the uniform circular array single antenna receiving model,and the simulation results show that the interference suppression performance is better.