`Through-wall human being detection using UWB impulse radar

Abstract

Ultra-wideband (UWB) impulse radar plays an important role in contactless vital sign (VS) detection. The VS can be extracted remotely by acquiring the oscillations in the human chest. Unfortunately, it is usually challenging to identify VS due to the low signal-to-noise ratio (SNR) only based on the traditional fast Fourier transform (FFT) especially in complicated conditions. To extract VS accurately, this paper presents a new scheme by analyzing the skewness characteristic of the received UWB impulses, which are modulated by life activities. The distance from the human subject to the radar antenna can be calculated by performing the discrete short-time Fourier transform (DSFT) on skewness. The frequency of human respiratory movement can be estimated based on the developed ensemble empirical mode decomposition (EEMD)-based accumulation technique by canceling out the harmonics effectively. The performance of the developed detection method is tested with several experiments carried out in different environments.

Detection of Breathing Rates in Through-wall UWB Radar Utilizing JTFA

“…In the radar system, we usually cannot achieve the maximum value of SNR by employing the traditional matched filter [36]. To improve SNR, another alternative technique is required i.e.…”

“…6(d). Accurate distance and frequency estimations can be achieved compared with the advanced method (AM) in [36]. SNR can be estimated as [37].…”

“…The frequency estimates are 0.32 Hz (400 cm), 0.26 Hz (700 cm), 0.29 Hz (1000 cm), and 0.26 Hz (1200 cm). The methods including AM [36], CFAR [37], and FOC [33] are used as references to compare with the presented algorithm. All results show the excellent capability of improving SNR, clutter and harmonic suppression.…”

“…Many algorithms for life sign detection have been proposed recently [23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42]. L. Liu analysed the time-frequency characteristic of human respiratory by employing the Hilbert transform based Fourier transform [23][24].…”

Clutter Elimination and Harmonic Suppression of Non-Stationary Life Signs for Long-Range and Through-Wall Human Subject Detection Using Spectral Kurtosis Analysis (SKA)-Based Windowed Fourier Transform (WFT) Method

“…Ultra-wideband (UWB) radar has been used to track moving targets and for through-wall imaging because of the good permeability and excellent resolution [6][7][8][9][10][11][12][13]. As a result, it has been proposed for vital sign detection [14][15][16][17][18][19][20][21][22] as shown in Figure 1. In [14], respiration-like clutter was suppressed using an adaptive cancellation method.…”