| Recent developments in integrated circuit and antenna technology have led to smaller,more efficient and more accurate radar systems.Radar technology has extended its use to an increasing number of applications such as automotive radar and security surveillance.With the help of the frequency modulated continuous wave(FMCW)radar regime and array antennas,millimeter wave radar is able to measure information such as distance,speed and direction of motion of moving targets within the beam range in real time with its low cost and high stability characteristics.With the growing market demand for low cost,small size and high performance radars,the engineering implementation of millimeter wave radars has become a new research hotspot.This project from the radar engineering project in the enterprise internship,and the main work of the thesis is divided into three aspects,as follows:(1)The principle and target detection theory of FMCW millimeter wave radar ranging and velocimetry under Chirp Sequence are investigated and the performance of the classical constant false alarm in different backgrounds is simulated and compared.The simulation results show that OS-CFAR detects better in multi-target and clutter-edge backgrounds.(2)The overall design of the radar digital signal processing system in this dissertation is proposed to address the shortcomings of current radar systems such as low sampling rate of echo signals and weak high-bandwidth data processing capability.The Zynq architecture has advantages in this design,which is capable of generating custom arithmetic hardware for computationally intensive tasks,where FPGA resources enable millimeter-wave radar to have adaptive and configurable capabilities similar to those of visual perception.These results demonstrated that the designed radar echo signal acquisition system has a signal-tonoise ratio(SNR)of 67 dB at 1MHz and an effective number of bits(ENOB)of 10.61 bit,enabling real-time acquisition of 4-way millimeter wave radar echo data at a 72 MSPS.(3)The method of digital signal processing of radar echo signals within the Zynq chip is investigated.In the PL part,the RDM is mainly obtained using the FFT,and in the PS part,an improved constant false alarm algorithm is used to further extract the target distance and speed information,and the results are sent to the computer for analysis via the Ethernet port.These results demonstrated that the system can achieve the vehicle target detection function,the FPGA logic resources improve the signal processing efficiency,compress the 2D FFT processing time to 2.7ms,optimize the system program running time to within 50 ms working cycle,and meet the radar system stability and real-time requirements. |
