Multipoint Combined Processing for FMCW LiDAR

Abstract

This paper proposes a multipoint processing method (MCP) for FMCW LiDAR. The proposed method reduces the number of fast Fourier transform (FFT) calculation compared to the traditional FMCW LiDAR method. This leads to a reduced power consumption. To end this, the proposed method accumulates the multiple beat frequencies in the time domain before the FMCW LiDAR extracts the measured distances from the beat frequencies using the fast Fourier transform (FFT). In order to distinguish the distances that are extracted from the FFT operation, a pulse-width modulation (PWM) counter and an analog comparator were applied. A hysteresis analog comparator was used to increase the immunity from the external noise. When the measured distances are too close to be indistinguishable by the FFT, it may fail to distinguish the measurement order. In order to respond to this situation, the proposed method includes a point-calibration algorithm. The root mean square error (RMSE) and hardware resource usage are utilized in order to assess the performance of the proposed method. The experimental results show that the proposed method achieves power usage time savings compared to the traditional method.