Passive extended double-sided two-way ranging algorithm for UWB positioning

Wireless sensor networks gain ground rapidly due to their potentially low cost. These networks, including variants with UWB (ultra-wideband) physical layer, can be utilized extremely well for positioning because of the technological capabilities. However, the accuracy of localization based on the measurement of time depends on the usage of timestamps provided by certain elements of the network. This article proposes a method to use time of arrival (ToA) also known as time of flight (ToF) measurements in an UWB technology-based passive asynchronous localization strategy (which provides low-power and quick positioning) in combination with extended two-way ranging to improve accuracy named by the authors as PE-ranging. The proposed method makes the positioning system more resistant to clock drift, while requires fewer messages due to the passive nature of the solution. First, the traditional variants of two-way ranging (TWR) are introduced, contributing the foundation of the proposed strategy, then the so-called PE-ranging is explained, which is a localization strategy based on indirect distance-measurement.