A Fundamental-and-Harmonic Dual-Frequency Doppler Radar System for Vital Signs Detection Enabling Radar Movement Self-Cancellation

We propose and experimentally demonstrate an ultra-wideband (UWB) chaos life-detection radar. The proposed radar transmits a wideband chaotic-pulse-position modulation (CPPM) signal modulated by a single-tone sinusoidal wave. A narrow-band split ring sensor is used to collect the reflected sinusoidal wave, and a lock-in amplifier is utilized to identify frequencies of respiration and heartbeat by detecting the phase change of the sinusoidal echo signal. Meanwhile, human location is realized by correlating the CPPM echo signal with its delayed duplicate and combining the synthetic aperture technology. Experimental results demonstrate that the human target can be located accurately and his vital signs can be detected in a large dynamic range through a 20-cm-thick wall using our radar system. The down-range resolution is 15[Formula: see text]cm, benefiting from the 1-GHz bandwidth of the CPPM signal. The dynamic range for human location is 50[Formula: see text]dB, and the dynamic ranges for heartbeat and respiration detection respectively are 20[Formula: see text]dB and 60[Formula: see text]dB in our radar system. In addition, the bandwidth of the CPPM signal can be adjusted from 620[Formula: see text]MHz to 1.56[Formula: see text]GHz to adapt to different requirements.

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A Wavelet-Based Ammunition Doppler Radar System

Wavelet Analysis and Its Applications - Lecture Notes in Computer Science ◽

10.1007/3-540-45333-4_47 ◽

2001 ◽

pp. 382-392 ◽

Cited By ~ 1

Author(s):

S. H. Ong ◽

A. Z. Kouzani

Keyword(s):

Doppler Radar ◽

Radar System

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Radar-Based Non-Contact Continuous Identity Authentication

Remote Sensing ◽

10.3390/rs12142279 ◽

2020 ◽

Vol 12 (14) ◽

pp. 2279 ◽

Cited By ~ 1

Author(s):

Shekh Md Mahmudul Islam ◽

Olga Borić-Lubecke ◽

Yao Zheng ◽

Victor M. Lubecke

Keyword(s):

Doppler Radar ◽

Vital Signs ◽

Identity Authentication ◽

Future Research ◽

Great Promise ◽

Healthcare Applications ◽

Privacy Concerns ◽

Vital Signs Monitoring ◽

Wide Range ◽

Physiological Sensing

Non-contact vital signs monitoring using microwave Doppler radar has shown great promise in healthcare applications. Recently, this unobtrusive form of physiological sensing has also been gaining attention for its potential for continuous identity authentication, which can reduce the vulnerability of traditional one-pass validation authentication systems. Physiological Doppler radar is an attractive approach for continuous identity authentication as it requires neither contact nor line-of-sight and does not give rise to privacy concerns associated with video imaging. This paper presents a review of recent advances in radar-based identity authentication systems. It includes an evaluation of the applicability of different research efforts in authentication using respiratory patterns and heart-based dynamics. It also identifies aspects of future research required to address remaining challenges in applying unobtrusive respiration-based or heart-based identity authentication to practical systems. With the advancement of machine learning and artificial intelligence, radar-based continuous authentication can grow to serve a wide range of valuable functions in society.

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