Research On Algorithm Of Frequency Modulated Continuous Wave Radar Ranging Process

Radar exist in all areas of modern human life, has an indispensable position. In actualuse, Linear frequency modulation continuous wave radar with its low transmitting power,high resolution, no blind spot detection, anti-interference ability, hardware implementationless difficult, etc., occupy an increasingly important position in all fields, therefore theresearch of LFMCW radar has high practical value.By consulting a large number of domestic and international information anddocumentation,firstly, in-depth study the system components and ranging principle ofLFMCW radar system,detailed analysis transmitted signal, the received signal, the beatsignal and interference signal of LFMCW radar system,and conduct simulation experiments;then focuses on the beat signal’s processing method in an ideal state, to be able to obtainmore accurate information on the target distance, were studied traditional FFT algorithm,Chirp-Z algorithm, the maximum spectral estimation algorithm and fitting algorithm’sprinciples and methods, and use these types of algorithm to process beat signal, thesimulation results obtained beat signal frequency and the target distance information; finally,propose an improved signal processing algorithms, it is about fitting algorithm and Chirp-Zalgorithm combining,use this algorithm to conduct simulation, and get beat signalfrequency and the distance to the target.Assuming different radar’s parameter settings and different target distance setting,several algorithms were taken to extract the beat signal frequency, compare the rangingresults. Simulation results show that traditional FFT algorithm proceeds target distance erroris larger under thesame conditions, Chirp-Z algorithm, the maximum spectral estimationalgorithm, fitting algorithm can effectively improve ranging accuracy,and the proposedfitting algorithm and Chirp-Z algorithm combined method can quickly and accuratelyextract the center frequency of the beat signal, able to raise a greater degree of LFMCWradar’s range accuracy; and no matter what kind of algorithm to be used in beat signalprocessing, when the system modulation bandwidth increases, the target distance accuracywill always improve,at the same time when the distance of test target increases, theaccuracy will be increased too.