Waveform Design And Parameter Estimation Of Transmit Diversity MIMO Radar

As a form of multiple-input multiple-output(MIMO)radar,transmit diversity MIMO radar can be regarded as the further development of phased array radar.The advantage of this radar system is its signal diversity,flexibility and capability to be extended,and thus it has obtained extensive and in-depth researches in recent years.By using orthogonalities of array elements,transmit diversity MIMO radar can form multi-beams at the same time at the receiver.The system makes full use of orthogonalities of the array elements,thus provides extra degrees-of-freedom(DoF),high angle resolution,strong clutter suppression and other advantages.In this paper,the transmit diversity MIMO radar waveform design and parameter estimation technology is studied.The main work includes:(1)In view of the transmit diversity MIMO radar waveform design problem,the transmit diversity MIMO radar is analyzed based on autocorrelation,cross correlation and ambiguity functions.For monostatic transmit diversity MIMO radar,the joint synthesis problem of orthogonal waveforms and mismatch filters is considered,and a joint optimization design method based on alternating direction method was proposed.The simulation results show that the method can effectively reduce the autocorrelation and cross-correlation sidelobes of orthogonal waveforms.For bistatic transmit diversity MIMO radar,based on its range-velocity ambiguity function,the range and velocity resolutions are analyzed,and an optimization method for orthogonal waveform design based on the target location is presented.The simulation results show that the method can improve the range and velocity resolutions according to the prior information of target location.(2)For the target time-delay and Doppler shift parameter estimation problem of the transmit diversity MIMO radar,adaptive pulse compression method is analyzed,and a new method is proposed based on Doppler compensation.Compared with matched filter group,this method is capable of extracting multiple targets in a single pulse.In view of the sparse target scenario,distributed compressed sensing(DCS)is applicable to estimate the target parameters of the transmit diversity MIMO radar,and then a novel method is developed to provide high estimation accuracy based on DCS.This method has the ability of super resolution,and its estimation accuracy is higher than that of adaptive pulse compression method,such as APES+Capon.(3)For the position-amplitude joint estimation problem of the transmit diversity MIMO radar,virtual array formation is discussed based on array model analysis.The scene reconstruction methods are given with rapid polar format algorithm(FPFA)and compressed sensing-based(CS)back projection(BP)method.The advantage of FPFA method is that the estimation is achieved by a single snapshot and the complicated motion compensation can be eliminated.Compared with time domain and other spatial spectral domain estimation methods,FPFA can greatly reduce the computational load of the system without interpolation operation.On the other hand,CS-BP algorithm can also avoid the interpolation operation.It eliminates high sidelobes under high SNR situation and is good for the reconstruction of weak targets.(4)For multicarrier transmit diversity MIMO radar,a new speed estimation method is proposed with the special phase relationship between different sub-carriers.Owing to the capability of high resolution imaging and speed estimation within a pulse,this method can be used for observing remote high speed and high maneuvering target under high SNR.Theoretical analysis and simulation results show that this method is simple and applicable to single and multiple scattering points scenario effectively.This paper also presents a new kind method for range and angle joint estimation for multicarrier MIMO radar.Based on this method,the speed estimation method of multicarrier radar is introduced,and we propose the multifunction multicarrier MIMO radar signal processing procedure and framework.