Signal Processing Method And Implementation Of Phased Array LFMCW Radar

In recent years,the increase in urban road vehicles has brought tremendous pressure to the traffic department,and the alleviation of congestion and early warning has become a new demand.LFMCW radar is more and more widely used in the civil field,especially in the field of traffic control.Therefore,research on LFMCW radar detection system with high performance and low cost has important application value.The main contents of this paper are as follows:According to the working principle of LFMCW,the signal system and modulation mode of LFMCW radar are described,the signal model and signal down conversion process are explained,at the same time,the feasibility is verified by simulation,the principle of radar ranging,velocity and direction finding is discussed in combination with the signal model and multi antenna oscillator model.The application of multi-dimensional FFT in LFMCW radar is discussed.The signal processing scheme of LFMCW radar is designed and implemented.The key algorithm processing flow of LFMCW radar detection target is given.The suppression effect of window function on sidelobe is analyzed.The algorithm of moving target indication and moving target detection is designed and verified by simulation.For engineering implementation,a two-dimensional fast Fourier transform method for ranging and velocity measurement is constructed based on pulse compression,moving target indication,target detection and other algorithms.The test results show that the target extraction algorithm used in this paper is easy to achieve in engineering and can make the radar detection system have stability.In order to further improve the detection probability,an adaptive threshold detection method with constant false alarm rate is proposed,and the CFAR detector is designed.This paper analyzes and compares the calculation process and characteristics of the unit average CFAR rate,large CFAR rate,small CFAR rate and orderly statistical CFAR rate detection algorithm.Based on the one-dimensional CFAR detector,it was extended to twodimensional CFAR detector,and the performance of the two-dimensional CFAR detector is simulated.The hardware platform,from the overall hardware platform structure to the key modules in the IF processing system,is designed and developed.The hardware modules are measured.At the same time,in terms of signal processing algorithm,combined with the radar hardware platform,the performance of target detection is tested.The test results show that the designed LFMCW radar detection system has the ability of moving target discrimination and recognition,which meets the design requirements.