Target Detection And Signal Processing For Millimeter-wave Short-range Detection Systems

Based on the application of short-range millimeter-wave detection technology and the related engineering project,this paper mainly studied and designed the millimeter-wave shortrange detection system of linear frequency modulation continuous wave(LFMCW)system.It is divided into analysis and design of the system,real-time signal processing algorithm research,software and hardware implementation,system debugging and experimental verification.The main research work includes:(1)The principle of range and velocity measurement of the LFMCW short-range detection system is analyzed,and the relevant parameters of the LFMCW short-range detection system are selected and determined by the application requirements of the system,which provides a theoretical basis for subsequent algorithm research and designs for software and hardware.(2)The beat signal processing flow of the LFMCW short-range detection system is introduced.Aiming at the problem of the large calculation amount of the algorithm when the LFMCW short-range detection system with variable period triangular wave modulation uses the tolerance function for multi-target pairing,an improved multi-targets pairing algorithm that uses prior information to compress the matching space is studied,which significantly reduces the complexity of multi-targets pairing;then in the constant false alarm processing algorithm,in view of the problem that the detection performance of Variability Index CFAR(VI-CFAR)drops sharply when there are interference targets in both sliding windows,it is improved by adding the ordered statistic with smallest option(OSSO)CFAR algorithm,the modified VICFAR detector can provide better detection performance in the environment where the interference targets are randomly distributed.Therefore,the robustness in practical applications is enhanced;the combination of the interpolation correction method and the multiple modulation zoom spectrum analysis method provides a higher frequency identification accuracy,which improves the detection accuracy of the system;the system is simulated in the case of single target and multi-target respectively in order to verify the effectiveness of the algorithm.(3)The hardware circuit of digital signal processing of the short-range detection system is designed.The selection and performance characteristics of DSP system circuits,PLL circuits,data acquisition circuits and other related module chips are explained around the overall structure of the system hardware,and the corresponding circuit schematic diagram is given.(4)The joint testing and debugging of software and hardware were completed for the whole system,the final results and intermediate data of the system were verified through signal sampling and spectrum analysis,the experimental prototype was simulated and tested at the outfield,and the measured performance of the system was analyzed and summarized.The feasibility of the signal processing algorithm and the hardware design were verified.The experimental results meet the overall performance requirements of the detection system.