基于激光调频连续波测距系统的频率估计研究

Frequency Estimation Research Based on Laser Frequency Modulated Continuous Wave Distance Measurement System

在调频连续波测距系统中,数据实时处理的快慢决定了系统的反应时间,当差拍信号的频率较高时,得到的数据量十分庞大,导致快速傅里叶变换所需的时间急剧增加,从而影响系统响应速度。提出一种基于中国余数定理的多频率抽样法,通过软件隔点抽样的方式来代替硬件多路欠采样,实现了对差拍信号频率精确的估计,很大程度上减少了计算的数据量,特别是在处理高频信号时,具有较大的优势。仿真结果证明了该方法的可行性,并展示了多频率抽样法在计算速度上的提升。

In frequency modulated continuous wave(FWCM)measurement system,real-time data processing speed is critical for system responsiveness.At high beat signal frequencies,the vast amount of data acquired significantly increases the time required for fast Fourier transform(FFT)calculations.In this paper,a multi-frequency sampling method based on the Chinese remainder theorem is proposed,which replaces the hardware multi-channel under-sampling by means of software sampling at intervals,realizes the accurate estimation of the frequency of the beat signal,and greatly reduces the calculated data.It has great advantages especially when dealing with high frequency signals.The simulation results prove the feasibility of the method and demonstrate the improvement of the calculation speed of the multi-frequency sampling method.