The Overview of Human Localization and Vital Sign Signal Measurement Using Handheld IR-UWB Through-Wall Radar

Abstract

Obtaining information (e.g., position, respiration, and heartbeat rates) on humans located behind opaque and non-metallic obstacles (e.g., walls and wood) has prompted the development of non-invasive remote sensing technologies. Due to its excellent features like high penetration ability, short blind area, fine-range resolution, high environment adoption capabilities, low cost and power consumption, and simple hardware design, impulse radio ultra-wideband (IR-UWB) through-wall radar has become the mainstream primary application radar used for the non-invasive remote sensing. IR-UWB through-wall radar has been developed for nearly 40 years, and various hardware compositions, deployment methods, and signal processing algorithms have been introduced by many scholars. The purpose of these proposed approaches is to obtain human information more accurately and quickly. In this paper, we focus on IR-UWB through-wall radar and introduce the key advances in system design and deployment, human detection theory, and signal processing algorithms, such as human vital sign signal measurement methods and moving human localization. Meanwhile, we discuss the engineering pre-processing methods of IR-UWB through-wall radar. The lasts research progress in the field is also presented. Based on this progress, the conclusions and the development directions of the IR-UWB through-wall radar in the future are also preliminarily forecasted.

Design of a Millimeter-Wave Radar Remote Monitoring System for the Elderly Living Alone Using WIFI Communication

“…In the LFMCW system, the frequency of the emission signal varies linearly over time. This periodic frequency scan was commonly referred to as chirp [ 23 , 24 , 25 , 26 , 27 ], as a linear FM pulse.…”

“…Sampling according to each frame cycle in the figure above, first ADC samples the median frequency signal according to the overall algorithm processing process, then distance dimension FFT processing, the target distance is calculated, and then a series of subsequent algorithm processing detection and separation of human respiratory and heartbeat signals [ 24 , 25 , 26 , 27 ].…”

Educational Low-Cost C-Band FMCW Radar System Comprising Commercial Off-the-Shelf Components for Indoor Through-Wall Object Detection

“…The time-varying distance (R) between the radar and object can be calculated as follows. In (6), B denotes bandwidth of the proposed FMCW radar system, f B is beat frequency, T is frequency rising time, and c is the speed of light. The maximum detection range (R M ) of the proposed FMCW radar is realized when the beat frequency of the FMCW radar equals f B .…”

“…There are numerous radar applications, such as radar-based range-breathing separation, monitoring of the worker activities, biomedical MIMO radars, radar systems for structural health monitoring, hand gesture recognition using micro-Doppler signatures, radars for unmanned aerial vehicles (UAVs), etc. Especially, radar technology is widely used in the military and internet of things (IoT) applications because it facilitates the development of remote-sensing equipment [1][2][3][4][5][6]. Military radars, such as those used in aerial defense, battlefield, and traffic-control operations, comprise large active phased-array systems to realize high-precision long-range detection (exceeding 100 km) and tracking [7][8][9].…”

Localization of Multi-Class On-Road and Aerial Targets Using mmWave FMCW Radar

“…Radars for medical applications are summarized in [4]. Human localization and vital signs measurements are explored, using hand-held through-wall imaging radar, in [5]. The detection and ranging of human targets in cluttered environments is proposed in [6].…”