基于互相关函数的毫米波雷达测距算法研究

Millimeter wave radar ranging algorithm based on cross-correlation function

经典的线性调频连续波(LFMCW)雷达测距方法用快速傅里叶变换(FFT)进行数据处理,采样点增多时计算量显著增长,使测距系统实时性不理想。为解决此问题引入了互相关函数测距方法,利用LFMCW雷达信号频率成三角形变化且回波延时小于一个周期的特点,进行一个周期内的相关运算就能测出距离值.结合互相关函数测距法测得的值,对采样信息的部分采样点进行FFT变换,可以快速高效地测出更精准的距离信息。MATLAB仿真实验表明,结合互相关函数的测距方法测距误差平均减小1.434 m,平均运算时间减少了0.5 s,提高了测距系统的实时性、精确性。

The classical linear frequency modulation continuous wave（LFMCW） radar ranging method adopts FFT transform to carry out signal processing. Calculation amount increases significantly with the sampling point increasing, which makes the real-time of ranging system not so ideal. To solve this problem, the crosscorrelation function ranging method is introduced. Using the characteristics that LFMCW radar signal frequency change is triangular and the echo delay is less than one cycle, the distance can be measured with only one cycle of cross-correlation operation. Combined with the measured value of the cross-correlation function ranging method, FFT transform is used for the partial sampling points of sampling information, and more accurate distance information can be measured quickly and efficiently. The simulation results of MATLAB show that the average ranging measurement error combing with cross-correlation function is reduced by 1.434 m and the average operation time is reduced by 0.5 s, which improves the real-time performance and accuracy of the ranging system.