基于离散双正交傅里叶变换的FMCW雷达测距方法

针对毫米波调频连续波（frequency modulated continuous wave, FMCW）雷达调制斜率的非线性带来测距误差问题，提出采用闭环控制与双正交傅里叶变换算法相结合的方法实现高精度测距。该方法首先通过分段降频得到非线性调制FMCW的片段，再用离散双正交傅里叶变换求出各段调制斜率，并按时间顺序排列生成校正曲线，最后用闭环控制进行非线性实时校正。实验结果表明,该方法使信号的调制斜率线性度误差下降到0.27%，测距误差降低了87%。

Ranging method of FMCW radar based on discrete biorthogonal Fourier transform

According to the problem of ranging error of the frequency modulated continuous wave(FMCW) radar is mainly from nonlinear modulate slope,a ranging method combining discrete bi-orthogonal Fourier transform(DBFT) algorithm with close-loop control circuits is proposed to realize high accuracy ranging.The method first obtains the segment of the nonlinear FMCW radar by segmentation lower frequency,then analyzes the modulated slope by DBFT,and chronologically creates correction curve,finally real time corrects the nonlinearity by closed loop control.The result shows that the modulation slope linearity error is down to 0.27%,and the ranging error reduced by 87%.