A Range Estimator of a Stationary Human among Stationary Clutter for Vital FMCW Radar

In this paper, we propose a range estimator of a stationary human among stationary clutter for frequency-modulated continuous-wave (FMCW) radar. The conventional FMCW radar is used to estimate the range and then heartbeat rate of the human. After estimating the range between the radar and the human first, the heartbeat signal of the human is analyzed to determine whether it is human or not. However, estimating the range of the human in a stationary clutter environment can involve the detection of other objects except humans because of various targets with the clutter. In order to solve this problem, we propose a method for estimating the range of human among a stationary clutter. The proposed structure consists of a combination of a high pass filter (HPF) and a range estimation algorithm. At this time, the range estimation algorithm uses an extrapolation technique, which is one of the high resolution algorithms, in order to increase the range resolution. As a result, in terms of range resolution 2.0m, the proposed algorithm can resolve humans in case of range interval 1.5m while the conventional FFT cannot resolve them at same range interval.