Extraction and Analysis of Micro-Doppler Signature in FMCW Radar

Micro-Doppler effect due to target micro-motions induce additional frequency components in the received radar signal. In addition to other target parameters, these micro-Doppler signatures can be used for target identification. For targets with high frequency micro-motion we observe that the conventional extraction of micro-Doppler signature in Frequency Modulated Continuous Wave (FMCW) radar fails due to insufficient sampling frequency along the slow-time. In this paper, we first develop a signal model for FMCW radar in the presence of a target with micro-motions. It can be inferred from the model that the micro-Doppler signature is preserved in the received signal. We then propose an approach to extract high frequency micro-Doppler signatures for FMCW radar, and verify it using simulation studies and experimental results.