Figure 1.
An illustration of the received radar pulses.
Figure 1.
An illustration of the received radar pulses.
Figure 2.
The time-range matrix with (a) only the respiration signal, and (b) the signal with additive white Gaussian noise (AWGN) at an SNR of −10 dB.
Figure 2.
The time-range matrix with (a) only the respiration signal, and (b) the signal with additive white Gaussian noise (AWGN) at an SNR of −10 dB.
Figure 3.
Flowchart of the proposed detection method.
Figure 3.
Flowchart of the proposed detection method.
Figure 4.
The (a) excess kurtosis, and (b) the kurtosis to SD (KSD) with a human subject, the (c) KSD without a human subject, (d) KSD in the target area, and (e) the spectrum of (d).
Figure 4.
The (a) excess kurtosis, and (b) the kurtosis to SD (KSD) with a human subject, the (c) KSD without a human subject, (d) KSD in the target area, and (e) the spectrum of (d).
Figure 5.
The time-frequency matrix using the wavelet transform (WT) decomposition (a) with a human subject at 9 m and (b) without a subject.
Figure 5.
The time-frequency matrix using the wavelet transform (WT) decomposition (a) with a human subject at 9 m and (b) without a subject.
Figure 6.
Signals in the time-frequency matrix (a) one in the region of interest (ROI), (b) one not in the ROI, (c) ten in the ROI, (d) ten not in the ROI and (e) all in the ROI.
Figure 6.
Signals in the time-frequency matrix (a) one in the region of interest (ROI), (b) one not in the ROI, (c) ten in the ROI, (d) ten not in the ROI and (e) all in the ROI.
Figure 7.
The Welch power spectrum of (a) d1, (b) d2, (c) d3, (d) d4, (e) d5, (f) d6, (g) d7, and (h) d8.
Figure 7.
The Welch power spectrum of (a) d1, (b) d2, (c) d3, (d) d4, (e) d5, (f) d6, (g) d7, and (h) d8.
Figure 8.
The time windows with (a) increasing length, and (b) fixed length.
Figure 8.
The time windows with (a) increasing length, and (b) fixed length.
Figure 9.
(a) The UWB radar and (b) the data for the first experiment with a human subject at a distance of 9 m from the radar.
Figure 9.
(a) The UWB radar and (b) the data for the first experiment with a human subject at a distance of 9 m from the radar.
Figure 10.
The experimental setup for (a) subjects in front of the radar, (b) subjects at an angle to the radar, (c) through-wall detection outdoors, (d) through-wall detection indoors and (e) the actuator.
Figure 10.
The experimental setup for (a) subjects in front of the radar, (b) subjects at an angle to the radar, (c) through-wall detection outdoors, (d) through-wall detection indoors and (e) the actuator.
Figure 11.
The results for the first experiment after (a) linear trend suppression (LTS), (b) range (fast time) filtering and (c) slow time filtering.
Figure 11.
The results for the first experiment after (a) linear trend suppression (LTS), (b) range (fast time) filtering and (c) slow time filtering.
Figure 12.
The KSD for the first experiment at distances of (a) 6 m, (b) 9 m, (c) 11 m and (d) 14 m from the radar.
Figure 12.
The KSD for the first experiment at distances of (a) 6 m, (b) 9 m, (c) 11 m and (d) 14 m from the radar.
Figure 13.
Range estimation for the first experiment at distances of (a) 6 m, (b) 9 m, (c) 11 m and (d) 14 m from the radar.
Figure 13.
Range estimation for the first experiment at distances of (a) 6 m, (b) 9 m, (c) 11 m and (d) 14 m from the radar.
Figure 14.
The signal in the ROI for the first experiment at distances of (a) 6 m, (b) 9 m, (c) 11 m and (d) 14 m from the radar.
Figure 14.
The signal in the ROI for the first experiment at distances of (a) 6 m, (b) 9 m, (c) 11 m and (d) 14 m from the radar.
Figure 15.
Frequency estimation for the first experiment at distances of (a) 6 m, (b) 9 m, (c) 11 m and (d) 14 m from the radar.
Figure 15.
Frequency estimation for the first experiment at distances of (a) 6 m, (b) 9 m, (c) 11 m and (d) 14 m from the radar.
Figure 16.
Results using the CFAR method for subject III in the first experiment at distances of (a) 6 m, (b) 9 m and (c) 11 m from the radar.
Figure 16.
Results using the CFAR method for subject III in the first experiment at distances of (a) 6 m, (b) 9 m and (c) 11 m from the radar.
Figure 17.
Results using AM for subject III in the first experiment at distances of (a) 6 m, (b) 9 m and (c) 11 m from the radar.
Figure 17.
Results using AM for subject III in the first experiment at distances of (a) 6 m, (b) 9 m and (c) 11 m from the radar.
Figure 18.
The KSD for the second experiment at distances of (a) 7 m, (b) 10 m, (c) 12 m and (d) 15 m from the radar.
Figure 18.
The KSD for the second experiment at distances of (a) 7 m, (b) 10 m, (c) 12 m and (d) 15 m from the radar.
Figure 19.
Range estimation for the second experiment at distances of (a) 7 m, (b) 10 m, (c) 12 m and (d) 15 m from the radar.
Figure 19.
Range estimation for the second experiment at distances of (a) 7 m, (b) 10 m, (c) 12 m and (d) 15 m from the radar.
Figure 20.
Frequency estimation for the second experiment at distances of (a) 7 m, (b) 10 m, (c) 12 m and (d) 15 m from the radar.
Figure 20.
Frequency estimation for the second experiment at distances of (a) 7 m, (b) 10 m, (c) 12 m and (d) 15 m from the radar.
Figure 21.
The KSD for the third experiment at distances of (a) 7 m, (b) 10 m and (c) 12 m from the radar.
Figure 21.
The KSD for the third experiment at distances of (a) 7 m, (b) 10 m and (c) 12 m from the radar.
Figure 22.
Third experiment range estimation at distances of (a) 7 m, (b) 10 m and (c) 12 m from the radar.
Figure 22.
Third experiment range estimation at distances of (a) 7 m, (b) 10 m and (c) 12 m from the radar.
Figure 23.
The signal in the ROI for the third experiment at distances of (a) 7 m, (b) 10 m and (c) 12 m from the radar.
Figure 23.
The signal in the ROI for the third experiment at distances of (a) 7 m, (b) 10 m and (c) 12 m from the radar.
Figure 24.
Third experiment frequency estimation at distances of (a) 7 m, (b) 10 m and (c) 12 m from the radar.
Figure 24.
Third experiment frequency estimation at distances of (a) 7 m, (b) 10 m and (c) 12 m from the radar.
Figure 25.
Results for the fourth experiment with the actuator outdoors (a) KSD, (b) range estimation and (c) the signal in the ROI.
Figure 25.
Results for the fourth experiment with the actuator outdoors (a) KSD, (b) range estimation and (c) the signal in the ROI.
Figure 26.
The results for the fifth experiment (a) KSD at 30°, (b) range at 30°, (c) KSD at 60° and (d) range at 60°.
Figure 26.
The results for the fifth experiment (a) KSD at 30°, (b) range at 30°, (c) KSD at 60° and (d) range at 60°.
Figure 27.
The signals in the ROI for the fifth experiment at angles of (a) 30° and (b) 60°.
Figure 27.
The signals in the ROI for the fifth experiment at angles of (a) 30° and (b) 60°.
Table 1.
The UMB Impulse Radar Parameters.
Table 1.
The UMB Impulse Radar Parameters.
Parameter | Value |
---|
center frequency | 400 MHz |
transmitted signal amplitude | 50 V |
pulse repeat frequency | 600 KHz |
number of averaged values (NA) | 30 |
time window | 124 ns |
number of samples (M) | 4092 |
input bandwidth of the Analog to Digital Converter (ADC) | 2.3 GHz |
ADC sampling rate | 500 MHz |
ADC sample size | 12 bits |
receiver dynamic range | 72 dB |
Table 2.
VS Estimates for Four Subjects at Different Distances.
Table 2.
VS Estimates for Four Subjects at Different Distances.
Subject | Gender | Height (cm) | Weight (kg) | Parameter | 6 m | 9 m | 11 m |
---|
I | Female | 158 | 48 | Frequency (Hz) | 0.26 | 0.31 | 0.31 |
SNR (dB) | −4.92 | −7.56 | −8.29 |
II | Female | 163 | 54 | Frequency (Hz) | 0.31 | 0.31 | 0.26 |
SNR (dB) | −7.08 | −10.6 | −11.0 |
III | Male | 178 | 84 | Frequency (Hz) | 0.37 | 0.31 | 0.37 |
SNR (dB) | −6.52 | −9.52 | −12.9 |
IV | Male | 182 | 76 | Frequency (Hz) | 0.37 | 0.31 | 0.37 |
SNR (dB) | −7.12 | −9.48 | −11.3 |
Table 3.
Performance for Subject I with Four Methods.
Table 3.
Performance for Subject I with Four Methods.
Method | Parameter | 6 m | 9 m | 11 m |
---|
CFAR | Range Error (m) | 4.36 | 6.72 | 9.54 |
Frequency (Hz) | 0.10 | 0.72 | 0.46 |
SNR (dB) | −8.22 | −12.86 | −15.26 |
Proposed | Range Error (m) | 0.12 | 0.17 | 0.11 |
Frequency (Hz) | 0.25 | 0.31 | 0.31 |
SNR (dB) | −4.91 | −7.55 | −8.28 |
MHOC | Range Error (m) | 2.43 | 1.56 | 7.25 |
Frequency (Hz) | 0.45 | 0.52 | 0.44 |
SNR (dB) | −6.85 | −9.58 | −12.35 |
AM | Range Error (m) | 5.46 | 4.67 | 3.98 |
Frequency (Hz) | 0.12 | 0.74 | 0.63 |
SNR (dB) | 0.84 | −3.69 | −6.59 |
Table 4.
VS Estimates for Three Distances.
Table 4.
VS Estimates for Three Distances.
Subject | Gender | Height (cm) | Method | Parameter | 7 m | 10 m | 12 m |
---|
I | Female | 158 | Proposed | Frequency (Hz) | 0.37 | 0.31 | 0.31 |
Range Error (m) | 0.04 | 0.05 | 0.08 |
SNR (dB) | −4.87 | −6.76 | −10.4 |
II | Female | 163 | FFT+ Window | Frequency (Hz) | 0.14 | 0.20 | 0.20 |
Range Error (m) | 0.15 | 0.27 | 11.7 |
SNR (dB) | −9.08 | −13.7 | −15.6 |
IV | Male | 182 | FFT | Frequency (Hz) | 11.7 | 11.7 | 11.7 |
Range Error (m) | 6.70 | 9.70 | 11.7 |
SNR (dB) | −29.4 | −31.9 | −32.2 |
Table 5.
Results with Four Methods at Different Distances.
Table 5.
Results with Four Methods at Different Distances.
Method | Parameter | 7 m | 10 m | 12 m |
---|
Proposed | Frequency (Hz) | 0.35 | 0.32 | 0.33 |
Deviation | 0.66% | 0.33% | 0.24% |
Range Error (m) | 0.026 | 0.043 | 0.040 |
FFT+Window | Frequency (Hz) | 0.37 | 0.37 | 0.12 |
Deviation | 11% | 11% | 64% |
Range Error (m) | 0.23 | 0.27 | 11.9 |
AM | Frequency (Hz) | 0.34 | 0.34 | 0.34 |
Deviation | 2.5 % | 2.5 % | 2.5 |
Range Error (m) | 0.40 | 0.37 | 8.70 |
CFAR | Frequency (Hz) | 0.37 | 0.37 | 0.43 |
Deviation | 11% | 11% | 28% |
Range Error (m) | 0.30 | 0.32 | 11.7 |
MHOC | Frequency (Hz) | 0.11 | 0.11 | 0.08 |
Deviation | 65% | 65% | 73% |
Range Error (m) | 0.47 | 0.62 | 0.47 |
Table 6.
Results for Different Azimuth Angles.
Table 6.
Results for Different Azimuth Angles.
Method | Parameter | 30° | 60° |
---|
MHOC | Frequency (Hz) | 0.37 | 0.26 |
Deviation | 11% | 23% |
Range Error (m) | 0.51 | 5.27 |
AM | Frequency (Hz) | 0.34 | 0.74 |
Deviation | 2.5% | 122% |
Range Error (m) | 13.73 | 13.73 |
FFT + Window | Frequency (Hz) | 0.14 | 0.14 |
Deviation | 57% | 57% |
Range Error (m) | 5.56 | 2.81 |
Proposed | Frequency (Hz) | 0.37 | 0.37 |
Deviation | 11% | 11% |
Range Error (m) | 0.10 | 0.10 |