| As a new radar system,MIMO radar has more advantages than traditional radar in target detection and parameter estimation.However,with the increase of MIMO radar bandwidths,it is a great challenge to use Nyquist sampling theorem to sample radar signal.In practical applications,radar targets often occupy only a few resolution units,that is,the target echo signal of the MIMO radar is sparse.Therefore,the Compressed Sensing(CS)theory can be used to sample the signal at a much lower rate than the Nyquist rate,and we obtain the effective information of the original signal by acquiring a small number of observation signals.Analogto-information converter(AIC)is a device for sparse signals,which obtains all information of a signal by acquiring a small number of observation signals.This paper proposes a single sample radar signal sampling method,this method can realize the compression sampling of the sparse signal in frequency domain and build a complete radar signal processing system,finally realize the real-time processing of the radar signal.The main work of this paper is as follows:1)In this paper,a new compressed sampling implementation method is proposed.In the single-sample radar signal sampling method,aiming at the sparse high-frequency radar signal in frequency domain,the radar echo signal in continuous multiple Pulse Repetition Interval(PRI)is approximately regarded as the same,and the compressed sampling of radar signal is realized through time-division sampling.In this paper,the mathematical model is used to analyze the single-sample radar signal sampling method.Using the Simulink simulation model in the scheme,after the compression sampling,we obtain the observation signal,then perform the target detection on the observation signal,and compare the detection result with the actual target position.It is proved that the sampling method can retain the effective information of the original signal,which verifies the feasibility of the scheme.2)Realize compressed sampling based on single sample radar signal sampling method,In the experiment,AWR1642 BOOST radar plate is adopted.We can set consecutive PRI cycles independently by taking advantage of the characteristics of the radar plate,so as to set the initial sampling time of ADC in consecutive PRI.The single-sample radar signal sampling method in time-division mode is realized and analyze the measured data,the implementation scheme is proved to be feasible.3)The single-sample radar signal processing system is built,and the single-sample radar signal sampling method is applied to the actual system.The target detection based on compression measurement is designed and realized.The system constructed in this paper is mainly divided into two parts: one is the radar signal acquisition terminal,which uses AWR1642 BOOST radar board to realize single sample radar signal sampling and obtain compressed measurement signal;the second is the signal processing end.In this paper,the millimeter-wave radar signal processing software is designed and written to process the compressed measured signal,detect the target position in the signal,and display the target information through the user interface.The single-sample radar signal sampling method proposed in this paper,the feature of using high-repetition radar signals is that the target position changes slowly in multiple PRIs,pseudorandom sequence controlled by low-speed clock signal is used to carry out random integration for sparse analog signals in frequency domain.In this process,there is no need for high-speed mixing circuit and high-speed clock signal.The compression sampling method has the characteristics of high compression rate and no distortion.After theoretical analysis and practical system verification,the single-sample radar signal processing system can be used to process high-bandwidth radar signals in real time,and the measurement error can be controlled within a resolution unit. |
