Design And Implementation Of Signal Processor For LFMCW Radar Based On FPGA

Due to its own characteristics and the increasingly mature radar technology,Linear Frequency Modulated Continuous Wave(LFMCW)Radar has been widely adopted in aviation,aerospace,meteorological observation,traffic control and other fields.This designed LFMCW radar is used for traffic flow monitoring.First,the article introduces the working principle of LFMCW radar.Since the single-slope FM signal can't solve the range-velocity coupling phenomenon,the symmetrical triangular wave frequency modulation signal can be used to solve the range-velocity coupling problem.At the same time,it introduces how to obtain the target speed,distance,azimuth and other issues.The LFMCW radar has high requirements on the processing speed in the signal processing process,and the real-time requirements are very high.The field programmable gate array(FPGA)has parallel and pipeline processing capability,which can meet the radar's real-time signal processing requirements.Therefore,the LFMCW radar signal processing department is designed based on FPGA.The FPGA uses the Spartan6 device from XILINX and is designed using Verilog in the ISE environment.Speed and resources are two important criteria for measuring FPGA design.In the design,multi-level pipeline and ping-pong operation caching mechanism is adopted to speed up the data processing speed,and the resource reuse technology is adopted to improve the utilization rate of resources.This paper mainly introduces FPGA design in signal processing,including:control design of LFMCW radar antenna transceiver module,signal processing algorithm implementation,FPGA and DSP interconnection.The LFMCW radar antenna transceiver module control is realized by FPGA controlled digital-analog-to-digital conversion.The EMIF and RapidIO interconnection protocols are used in the interconnection process between FPGA and DSP to realize the communication between FPGA and DSP.When the signal is transmitted by the LFMCW radar antenna,the nonlinearity of the signal is caused by the electrical characteristics of the voltage controlled oscillator(VCO),This paper uses the least squares curve fitting algorithm to perform nonlinear correction,The algorithm is simple and easy to implement,and the verification effect is obvious.The beat signal received by the radar has clutter and noise interference,In the design,one-dimensional FFT,cancellation and CFAR are used to realize clutter suppression.This paper proposes an FPGA-based OS-CFAR implementation method,which uses less resources and runs faster,And verified by simulation.