Investigations on passive channel impulse response of ultra wide band signals for monitoring and safety applications

A growing number of devices, from car key fobs to mobile phones to WiFi-routers, are equipped with ultra-wideband radios. In the network formed by these devices, communicating modules often estimate the channel impulse response to employ a matched filter to decode transmitted data or to accurately time stamp incoming messages when estimating the time-of-flight for localization. This paper investigates how such measurements of the channel impulse response can be utilized to augment existing ultra-wideband communication and localization networks to a multi-static radar network. The approach is experimentally evaluated using off-the-shelf hardware and simple, distributed filtering, and shows that a tag-free human walking in the space equipped with ultra-wideband modules can be tracked in real time. This opens the door for various location-based smart home applications, ranging from smart audio and light systems to elderly monitoring and security systems.

Section: Related Workmentioning

confidence: 99%

Section: Cir Measurements With Two Dwm1000 Transceiversmentioning

confidence: 99%

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A Multi-Static Radar Network with Ultra-Wideband Radio-Equipped Devices

Ledergerber

D’Andrea

2020

“…Because consecutive CIR measurements do not necessarily start at the same time, we need to align the CIR measurements as shown in Figure 8 . The Decawave DW1000 applies an internal leading-edge algorithm that provides the time stamp of the rise of the 0-th multipath component MPC0 as a combination of an integer part and a fractional part [ 27 ]. Those values are shown by the dashed lines in Figure 8 a.…”

Section: Methodsmentioning

confidence: 99%

MAMPI-UWB—Multipath-Assisted Device-Free Localization with Magnitude and Phase Information with UWB Transceivers

Cimdins

Schmidt

Hellbrück

2020

In this paper, we propose a multipath-assisted device-free localization (DFL) system that includes magnitude and phase information (MAMPI). The DFL system employs ultra-wideband (UWB) channel impulse response (CIR) measurements, enabling the extraction of several multipath components (MPCs) and thereby benefits from multipath propagation. We propose a radio propagation model that calculates the effect on the received signal based on the position of a person within a target area. Additionally, we propose a validated error model for the measurements and explain the creation of different feature vectors and extraction of the MPCs from Decawave DW1000 CIR measurements. We evaluate the system via simulations of the position error probability and a measurement setup in an indoor scenario. We compare the performance of MAMPI to a conventional DFL system based on four sensor nodes that measures radio signal strength values. The combination of the magnitude and phase differences for the feature vectors results in a position error probability that is comparable to a conventional system but requires only two sensor nodes.

“…As the phase difference between the transmitter and receiver clock varies from one signal transmission to another due to clock imperfections, the CIR envelope samples obtained during each signal reception show different temporal locations and a different phase offset. To obtain a higher resolution of the CIR envelope, these accumulated CIR envelope measurements can be aligned by Decawave’s proprietary leading edge detection algorithm [31], as discussed in detail in [32]. This leading edge detection algorithm estimates the first path location within a CIR envelope with a resolution of 15.6 ps.…”

Section: Channel Impulse Responsementioning

confidence: 99%

Ultra-Wideband Angle of Arrival Estimation Based on Angle-Dependent Antenna Transfer Function

Ledergerber

D’Andrea

2019

Ultra-wideband radio signals are used in communication, indoor localization and radar systems, due to the high data rates, the high resilience to fading and the fine temporal resolution that can be achieved with a large bandwidth. This paper introduces a new method to estimate the angle of arrival of ultra-wideband radio signals with which existing time-of-flight based localization and radar systems can be augmented at no additional hardware cost. The method does not require multiple transmitter or receiver antennas, or relative motion between transmitter and receiver. Instead, it is solely based on the angle-dependent impulse response function of ultra-wideband antennas. Datasets on which the method is evaluated are publicly available. The method is further applied to a localization problem and it is shown how a robot can self-localize solely based on these angle of arrival estimates, and how they can be combined with time-of-flight measurements. Even though existing angle of arrival techniques that use multiple antennas show better accuracy, the method presented herein looks promising enough to be developed further and could potentially lead to electronically and mechanically simpler angle of arrival estimation technology.