Frequency-Modulated Continuous-Wave Laser Ranging With Sub-Nyquist Sampling Rate Using Asymmetric Chirped Waveforms

Abstract

We propose a frequency-modulated continuous-wave (FMCW) laser range with sub-Nyquist sampling rates in which asymmetric chirped waveforms are used. Different de-chirped signals can be generated since the up-chirp and the down-chirp sections have different chirp rates. The distances are extracted at a sub-Nyquist sampling rate using a modified Vernier sampling, in which the sub-Nyquist sampling technique ratio is reconfigurable by changing the ratios of the chirp rates. A demonstrated experiment is carried out. The lengths of fiber can be measured with a sub-Nyquist sampling ratio of 1/10. Therefore, the proposed method reduces the sampling rate in the FMCW laser ranging system using Vernier sampling. Moreover, only a single-shot sampling is required, which reduces the complexity of the Vernier sampling.