Toward Elderly Care: A Phase-Difference-of-Arrival Assisted Ultra-Wideband Positioning Method in Smart Home

Abstract

Location-based services (LBSs) for elderly care is a trending topic in smart homes. The key issue is the high accurate positioning for the elderly. Ultra-wideband (UWB) is a centimeter-level positioning accuracy in line-of-sight (LOS) environments. However, most of existing UWB positioning methods need non-line-of-sight (NLOS) identification and compensation, and thus leading to severe deterioration in positioning accuracy in presence of complex indoor environments where the elderly lived. This article proposes a phase-difference-of-arrival (PDOA) assisted UWB positioning method (PDOA-UWB) for elderly care. In our positioning framework, we first calculate the phase difference of arrival from PDOA chip integrated in the UWB base stations (BSs) to obtain a coarse location of the elderly, which is further used to distinguish which nearby BSs are in LOS environments and which are in NLOS environments. Then, a PDOA-UWB positioning solution is derived to improve the positioning accuracy of the elderly. Compared with some existing methods, our method achieves higher accuracy with less NLOS compensation, and is easier to be implemented in complex indoor environments for simple practical engineering applications. Experimental results show the efficacy of our proposed method. INDEX TERMS Phase-difference-of-arrival (PDOA), location-based services (LBSs), ultra-wideband (UWB) positioning, smart home, indoor positioning

High-Precision RTT-Based Indoor Positioning System Using RCDN and RPN

“…On the other hand, in the TOF method, the distance estimation is based on the transmission/reception time of the radio waves in real-time using chirp-based [ 17 , 18 ] and ultra-wide band (UWB) communications, etc. [ 19 , 20 , 21 ]. The ranging based on RTT has generally higher accuracy with respect to the RSSI-based Fingerprint method with a positioning resolution of 2–3 m. The positioning accuracy also depends on the technology used for RTT estimation.…”

Emerging Technologies for Next Generation Remote Health Care and Assisted Living

“…An RFID-wearable (integrated, e.g., in cloth) based tracking solution, providing a notification to a caregiver in case the patients leaves the pre-defined area, has been developed by the authors in [217]. Two another tracking and fall notification solutions have been suggested in [219] and [222]. Zhang et al [219] shape their solution in a hand-watchlike wearable and equip it with the UWB time difference of arrival localization module, which determines the position of the user with respect to static UWB anchor devices.…”

“…Two another tracking and fall notification solutions have been suggested in [219] and [222]. Zhang et al [219] shape their solution in a hand-watchlike wearable and equip it with the UWB time difference of arrival localization module, which determines the position of the user with respect to static UWB anchor devices. The wearable solution reported in [222] is primarily intended for outdoor use, for which reason the prototype utilizes the NB-IoT cellular technology and a GNSS module for positioning.…”

Emerging Technologies for Next Generation Remote Health Care and Assisted Living

“…An RFID-wearable (integrated, e.g., in cloth) based tracking solution, providing a notification to a caregiver in case the patients leaves the pre-defined area, has been developed by the authors in [215]. Two another tracking and fall notification solutions have been suggested in [217] and [220]. Zhang et al [217] shape their solution in a hand-watch-like wearable and equip it with the UWB time difference of arrival localization module, which determines the position of the user with respect to static UWB anchor devices.…”

“…Two another tracking and fall notification solutions have been suggested in [217] and [220]. Zhang et al [217] shape their solution in a hand-watch-like wearable and equip it with the UWB time difference of arrival localization module, which determines the position of the user with respect to static UWB anchor devices. The wearable solution reported in [220] is primarily intended for outdoor use, for which reason the prototype utilizes the NB-IoT cellular technology and a GNSS module for positioning.…”