Signal Processing Algorithm And Implementation Of Millimeter Wave Active Detection System

Millimeter-wave radar has a wide range of applications in short-range,efficient ranging algorithm and a stable hardware circuit is an important guarantee for high-precision ranging.Based on the research background of 3 mm active detection system,the high precision algorithm and the hardware circuit design of the active radar are studied in depth.According to the practical application,a signal processing system is designed.The main work is as follows:1?The basic principle and implementation scheme of LFMCW radar active detection are introduced.The structure model of the system is given,and the difference frequency signal model is established and the related parameters are analyzed.2?Based on the simple,high precision and easy to realize of the ratio method,analyze the performance of the Rife algorithm and the amplitude and Combined Amplitude and Phase Interpolation Algorithm(CAPI).The algorithm of combining Rife and amplitude and phase is proposed;secondly,the performance of the Jacobsen algorithm and Quinn algorithm are analyzed,and the J-Quinn algorithm is proposed.Two improved algorithms have improved the accuracy of the estimation of the difference frequency signal.3?Because the FFT transform has the disadvantage of the picket fence effect?spectral leakage and the resolution is not high,and some shortcomings of the algorithm in multi frequency estimation.In this paper,a modern spectral estimation method based on MVDR model is proposed for LFMCW radar ranging.Based on the traditional MVDR spectrum estimation method,Adaptive Frequence Estimation Algorithm Based on Steepest Descent Method(AFEA-SD)is proposed.In this method,the spectrum peak search based on the iterative strategy is different from the traditional search method,which can improve the accuracy of frequency estimation while reducing the amount of computation.The results show that this algorithm can effectively overcome the inherent defects of FFT transform,and has the advantages of high resolution,high estimation precision,small calculation amount and can be used for multi frequency estimation.4?Combined with the project needs,the FPGA XC3S50 as the core device,the hardware circuit design and implementation of the three parts of the signal generation,difference frequency signal sampling and difference frequency signal processing are completed.Focus including power generation,clock control and simulation JTAG and other auxiliary module circuit design,as well as digital analog conversion,voltage comparison,difference frequency signal sampling and other ranging module circuit design.At the same time,it gives the overall system schematic diagram and printed circuit board.5?In order to verify the feasibility of the system,the hardware and software of the system are combined to simulate the experiment.The performance of each algorithm and the reliability of the design of the hardware circuit are tested.