Research On Parameter Estimation Of Vibrating Target In Frequency-modulated Continuous Wave Radar

The FMCW radar system has the advantages of high sensitivity,low power consumption,strong penetrability,and low hardware cost.It is less affected by the weather and can work around the clock.Therefore,it is of great significance to carry out non-contact vibration target monitoring research based on FMCW radar.Based on FMCW radar system,this paper studies the monitoring technology of non-contact vibration target from the aspects of software algorithm research and hardware equipment improvement.Firstly,the working principle of FMCW radar for monitoring vibrating targets is described,and a vibration target signal model is established for the non-contact FMCW radar monitoring system for vibrating targets,and the theoretical basis is established for the parameter estimation of the vibration targetSecondly,this paper studies the parameter estimation algorithm of the FMCW radar vibration target monitoring system.The Cramero lower bound for parameter estimation is derived firstly;then,two parameter estimation algorithms based on Fast Fourier Tranform(FFT)and Maximum Likelihood(ML)are analyzed by system simulation.Monte Carlo simulation results show that,compared with parameter estimation algorithm based on Fast Fourier Tranform(FFT),parameter estimation algorithm based on Maximum Likelihood(ML)has higher estimation accuracy.Thirdly,this paper analyzes the principle of spectrum estimation algorithm and the error factors of frequency estimation.Based on the original parameter estimation algorithm,two frequency estimation optimization algorithms based on improved Rife and improved Quinn are proposed.Experimental results show that both the improved Rife-based and improved Quinnbased estimation algorithms can improve the accuracy of parameter estimation of the vibration target by increasing the accuracy of frequency estimation.Finally,in order to solve the problem of low parameter estimation accuracy under the condition of low signal-to-noise ratio,this paper proposes a planar focusing lens based on the phase shift surface(PSS)principle to improve the signal-to-noise ratio of the target vibration signal.Based on the Malta unit structure,a new type of lens unit structure was improved to achieve a 360 ° phase shift range under high-efficiency transmission.The plane focusing lens is designed and simulated based on the phase compensation principle.The simulation results show that the plane focusing lens can effectively achieve beam focusing,thereby improving the accuracy of the vibration target parameter estimation.