A Study On Target Parameters Estimation Of Missile-borne FDA-MIMO Radar

Frequency diversity array is a special form of phased array.It differs from phased array in that there is a small frequency difference in the carrier frequency of the transmitted signals of each element of FDA.By combining with MIMO radar,FDA-MIMO radar is formed.The freedom of frequency diversity array is virtual to the receiving end,thus forming a virtual guidance vector for joint receive-transmit.So it provide conditions to estimate the azimuth information and range information of the target to make full use of the range dimension information which provided by FDA-MIMO radar.However,because the range and angle of the transmit beampattern in the frequency diversity array are coupled,it is quite difficult to obtain the parameter information of the target directly or even the range information without ambiguity through the conventional FDA-MIMO radar beam.In this thesis,the problem of radar range ambiguity in FDA-MIMO system is studied.The main research work and progress are as follows:1.The parameter design of missile-borne FDA-MIMO radar is studied.Aiming at the dependence between missile-borne range ambiguity and pulse repetition frequency,the relationship between pulse repetition frequency and beam angle of view and incidence angle is analyzed,and the dependence relationship between them is obtained through simulation,so as to select pulse repetition frequency.Aiming at the dependence between clutter range ambiguity and frequency increment of FDA-MIMO radar,according to simulation results,By choosing the frequency increment,the separation of spatial double fuzzy clutter can be realized.2.According to the characteristics of FDA-MIMO radar system,the advantages of the system are verified by simulation.Firstly,aiming at the problem of target parameter estimation,this thesis simulates the common beam scanning algorithm to illustrate the range ambiguity characteristics of the radar system,and achieves the unambiguous estimation of the single target parameters of the radar system by subarray partition method.Secondly,in order to solve the problem of clutter ambiguity,this thesis applies the quadratic distance-dependent compensation algorithm to separate clutter in different ambiguous regions in space.3.Aiming at the range ambiguity problem of FDA-MIMO radar,two range ambiguity resolution algorithms of FDA-MIMO radar are proposed in this thesis.Firstly,distance ambiguity resolution based on double-frequency offset method is proposed.Through joint search of music power spectrum estimation from two frequency increment received data,not only the accuracy of parameter estimation is improved,but also the maximum ambiguity-free distance of the system is enlarged,and the problem of distance ambiguity is solved in a certain range.Then,through the study of non-linear frequency offset method,the basis is proposed.In order to solve the range ambiguity by sinc frequency offset method,this method can form narrow beams in the range-angle dimension.It can not only decouple the transmitted beams,but also effectively estimate the multi-objective parameters.