基于包络锁相的AMCW高精度测距算法

AMCW High Precision Ranging Algorithm Based on Envelope Phase Locking

调幅连续波(Amplitude Modulated Continuous Wave,AMCW)信号用于短距目标探测中具有波形简单、占用带宽小、测距精度高的优势。针对AMCW信号在低信噪比情况下其测距精度明显下降的问题,提出了一种基于锁相环(PLL)的包络信号跟踪算法。利用锁相环具有窄带滤波特性与良好的跟踪特性,对含噪声的包络信号进行捕获与跟踪,降低了噪声的影响,在不同场景下给出了锁相环的环路参数及其适用条件。仿真和实验结果表明,相比于原有AMCW,该方法在低信噪比下体现出更好的鲁棒性。

Amplitude Modulated Continuous Wave(AMCW)signals have the advantages of simple waveform,small occupied bandwidth and high ranging accuracy in short-range target detection.Aiming at the problem that the ranging accuracy of AMCW signals is significantly reduced under the condition of low signal-to-noise ratio,an envelope signal tracking algorithm based on Phase-Locked Loop(PLL)is proposed.The PLL has narrow-band filtering and good tracking performance to capture and track noise-containing envelope signals,reducing the influence of noise.The loop parameters and applicable conditions of the PLL are given in different scenarios.Simulation and experiment results show that compared with the original AMCW,this method has better robust performance under low signal-to-noise ratio.