Ultra-wideband (UWB) is a promising mean for elderly care in line-of-sight (LOS) environments. One major limitation of UWB-based localization is the non-line-of-sight (NLOS) for signals caused by severe environments, resulting in dramatic performance degradation. Although many NLOS identification and compensation methods in presence of complex indoor environments have been proposed, they are only applicable to specific environments or require enough LOS BSs to detect NLOS measurements. To address these issues comprehensively, we propose a phase-difference-of-arrival (PDOA) assisted UWB positioning method (PDOA-UWB) for elderly care in this paper, which consists of three steps: (1) coarse localization, calculated from PDOA measurements at multiple receiver antennas of UWB base stations (BSs), (2) LOS BSs selection, and (3) fine localization through a convex regression estimator. Our method is simple and effective and can be used in various practical environments without prior information about the NLOS error. Overall experimental results verify that PDOA-UWB can achieve better positioning accuracy than existing methods in severe NLOS environments.

在视距（LOS）环境中，超宽带（UWB）是老年人护理的一种有前途的手段。基于UWB的本地化的主要限制之一是严重环境导致的信号的非视线（NLOS），导致性能急剧下降。尽管已经提出了许多在复杂室内环境中存在的NLOS识别和补偿方法，但它们仅适用于特定环境或需要足够的LOS BS来检测NLOS测量值。为了全面解决这些问题，我们提出了一种针对老年人护理的相差到达（PDOA）辅助UWB定位方法（PDOA-UWB），该方法包括三个步骤：（1）根据PDOA计算出的粗略定位UWB基站（BS）的多个接收天线的测量，（2）LOS BS的选择，（3）通过凸回归估计器进行精细定位。我们的方法简单有效，可以在各种实际环境中使用，而无需有关NLOS错误的事先信息。总体实验结果证明，在恶劣的NLOS环境中，PDOA-UWB可以比现有方法获得更好的定位精度。