The Signal Processing System Design And FPGA Realization Of The Ground Moving Target Reconnaissance Radar

Ground moving target reconnaissance radar can accomplish the monitoring of the ground moving targets such as personnel and vehicles.It is widely applied in fields such as battlefield reconnaissance and security.It is significant to improve ground detection radar target detection performance to carry out ground target reconnaissance radar signal processing algorithms.In this paper,the general two-phase coded signal,multi-phase coded signal and chirp signal of ground-based reconnaissance radar are analyzed.A wide and narrow pulse combined frequency-division multiplexing waveform based on chirp signal is designed.By using narrow/wide pulse simultaneously for short/long-range target detection,it can well take into account the minimum/maximum range of performance requirements.Aiming at the sidelobe suppression of chirp signal,a low sidelobe pulse pressure filter based on convex optimization algorithm is proposed.By adding the constraints of SNR loss and mainlobe broadening to the filter model to achieve the minimum of output sidelobe level.For the ground clutter received by ground-based reconnaissance radar,four typical ground distribution models are analyzed.The zero-memory nonlinear transformation method is used to simulate ground clutter for Weibull distribution.Clutter suppression is based on fractional Fourier transform,which takes advantage of chirp signal energy concentration characteristic on the fractional Fourier transform domain.Due to the sparsity characteristic of radar target echo signal,a multi-period target detection algorithm based on compressed sensing is proposed.The algorithm adopts sparse-Doppler grid method to design sparse matrix,selects Gaussian random matrix as observation matrix,reconstructs the signal by orthogonal matching pursuit method,obtains the target distance and velocity,avoids the steps of pulse compression,reduces the amount of computation,improves processing speed and detection performance.Finally,Based on the FPGA signal processing platform,the generation of radar signal and the processing of IF echo signal are realized.The signal processing algorithms include DDC,mismatched pulse compression,intra-frequency asynchronous interference suppression and FFT.The processing results of each module are compared with the simulation results to verify the correctness of the algorithm.