Research On The Intra-pulse Modulation Recognition And Parameter Estimation Algorithms Of Centralized MIMO Radar

MIMO radar is a new radar system,this kind of radar transmits and receives data through the multiple antennas of transmitting terminal and receiving terminal,and it has the characteristics of anti-stealth,low probablility of intercept,anti-jamming and high-resolution performance and so on.It is very difficult to detect the MIMO radar,and it is very important to identify the modulation type of MIMO radar signals effectively and estimate the parameters of radar signal accurately for the research of the MIMO radar antagonism.Aiming at the problem of reconnaissance of MIMO radar,the three common signals of centralized MIMO radar are taken as the research foundation,and through the two aspects of theoretical analysis and computer simulation,the following three parts have been discussed.1.The basic principle of the centralized MIMO radar and three kinds of commonly used signals of this kind of radar have been studied.The time and frequency characteristics of these three typical MIMO radar signals have been theoretically analyzed,and the process of the MIMO radar receiving signal has been discussed,which involves the matched filtering,the virtual array technology,and digital beam forming and so on.Finally,the detection model of centralized MIMO radar has been simply analysed.2.The modulation recognition algorithms of centralized MIMO radar signals have been studied,including the recognition algorithm based on the part of the zero time delay self-correlation spectrum and the recognition algorithm based on Short Time Fourier Transform(STFT).The time-frequency characteristics of linear frequency modulated(LFM)MIMO radar signal,phase coding(PC)MIMO radar signal and frequency coding(FC)MIMO radar signal have been theoretically analyzed.Aiming at the MMO radar signals,the modulation recognition algorithm based on instantaneous autocorrelation has been studied,and the modulation type of MIMO radar signals could be identified effectively by using this kind of algorithm under the condition of reducing the computational load.Aiming at the MIMO radar signals which are delt with blind source separation,the modulation recognition algorithm based o n STFT have been uesd,and the validity and feasibility of the algorithm have been validated by simulation.3.The parameters estimation algorithms for the centralized MIMO radar signals have been studied.Aiming at the radar signals which are under the condition of modulation recognition,specific algorithms have been used for the research of parameters estimation.As for LFM radar signal,the estimation algorithm based on STFT has been analysed,and as for the PC radar signal,the estimation algorithm based on multi-scale haar wavelet transform method has been studied to estimate the sub-code width of the PC radar signal,while the estimation algorithm based on STFT has been used to estimate the sub-code width of FC radar signal.Finally,the simulation results have been studied to verify the estimation effect under the different Signal-to-Noise Ratio(SNR).Within the range of allowable estimation error,the parameters of these three kinds of MIMO radar signals could be estimated precisely by using the algorithms proposed in this paper.Based on the research of the above three parts,namely on the basis of theoretical analysis of the working principle of MIMO radar and the time and frequency characteristics of commonly used radar signals,the research of modulation recognition of MIMO radar have been conducted from two aspects,including using MIMO radar signals directly and using the radar signals which are engendered by MIMO radar signals after blind source separation.Finally,the relevant parameter estimation algorithms have been studied to extract the important parameters of the radar signals to obtain the favorable information against MIMO radar.