Implementation Of Radar Signal Detection Algorithm Based On DBF

The radar signal detection algorithm based on digital beam-forming can form beam for multiple targets and achieve accurate angle estimation,therefore it has important research value.Among them,the digital beam-forming technology plays an important role.In this paper,the FPGA implementation of the algorithm is completed by theoretical simulation,scheme demonstration and hardware implementation.The design goal of this paper is to realize the amplitude-phase correction of the receiving channel,the digital beam-forming of the wide-band receive signal,and finally complete the angle estimation of the target.In this paper,the theoretical basis of digital beam-forming is introduced in detail,and then the angle estimation algorithm is introduced.At last,the algorithm about sparse signal recovery based on bayesian compressive sensing is proposed.From the perspective of the implementation of the algorithm,a classical method of amplitude measurement is used in the program.In the scheme,a constant beam-width beam-former based on spatial resampling is used to generate 16 beams simultaneously,the beam-former can generate digital beam with fixed mainlobe width to the input signals of different frequency bands,thus overcoming the frequency shift phenomenon of the wideband signal.It can satisfy the complicated signal environment in engineering application.The direction estimation method uses the amplitude direction finding algorithm,and compares the maximum beam and the second beam in the 16 beams to obtain the corresponding amplitude value,and then compares with the amplitude ratio in the direction finding library obtained through the actual test,a similar magnitude ratio can be found to determine the corresponding target angle.Although the accuracy of direction finding is not high,but the method is simple in principle and low in resource consumption,and it is easy to be realized in engineering,so it is be used widely.The scheme is based on Xilinx Virtex-7 series FPGA chip.Under the control of the host computer,the chip realizes 16 channels calibration,fixed frequency direction estimation and broadband frequency direction estimation.The experimental results show that the proposed method can generate 16 directional beams stably,covering the area from-45 to +45,and successfully estimates the angle of the signal with the bandwidth of 60 MHZ in the frequency band from 800 MHz to 4960 MHz.The root mean square error of the angle is 0.17 degree,it can meet the program requirement.