Research On LFMCW Radar Echo Signal Simulation And FPGA Verification Technology

This paper mainly performs detailed theoretical analysis and software simulation of the linear frequency modulation continuous wave radar echo signal simulation,and performs FPGA system design and verification.Through the close cooperation of Quartus II software and FPGA chip,the single-channel and multi-channel Simulation of target echo of single target and multi-target LFMCW radar,and verification of hardware system.In the verification of multi-channel systems,this paper proposes an improved multiple signal classification algorithm for the problem of low resolution of traditional multiple signal classification algorithms when the target angles are close,and takes the L-shaped array as an example for in-depth theoretical analysis and simulation verification.It is proved that the algorithm can effectively improve the resolution of DOA estimation.The main work of the thesis is as follows:(1)The transmission signals of LFMCW radar are analyzed,and the ranging,speed and direction finding principles of LFMCW radar are introduced.The radar target model is analyzed,and several commonly used target amplitude fluctuation models are analyzed.Aiming at the background signal in radar echo,several commonly used amplitude probability distribution models of ground clutter and noise are introduced.(2)The overall frame structure of the LFMCW radar echo signal simulation system is determined,and the formula derivation and Matlab simulation of each module are performed.The target fluctuation model of the Swerling type distribution and the ground clutter of the Weibull distribution were analyzed and modeled,and the simulation was verified by Matlab.(3)The hardware design of the single-channel and multi-channel,and single-target and multi-target LFMCW radar echo simulation system.The hardware module is designed by Quartus II software,and the design block diagram and principle analysis of each module are given.The hardware system is implemented by FPGA.(4)Perform module verification,system unified adjustment,single-channel speed-measuring and range-finding verification,and multi-channel direction-finding verification on the hardware-implemented LFMCW radar echo simulation system,and use Signal Tap to capture the output signals of each module during board-level debugging.And combined with Matlab to analyze and verify the correctness of the hardware system.(5)Aiming at the problem of low resolution of the traditional multiple signal classification algorithm when the target orientations are close,an improved multiple signal classification algorithm is proposed,which improves the measurement performance of the system when the multiple target signal arrival angles are close,and the simulation results verify that its effectiveness.