On the Accuracy of Localization Systems Using Wideband Antenna Arrays

Abstract

Accurate positional information is essential for many applications in wireless networks. Time-of-arrival (TOA) and angle-of-arrival (AOA) are the two most commonly used signal metrics for localizing nodes with unknown positions. In this paper, we consider a wireless network in which each node is equipped with a wideband antenna array capable of performing both TOA and AOA measurements. Since both the position and orientation of the agent are of interest, we propose a localization framework that jointly estimates these two parameters. The notion of equivalent fisher information is applied to derive the squared error bounds for the position and orientation. Since our analysis starts from the received waveforms rather than directly from the signal metrics, these bounds characterize the fundamental limits of the position and orientation accuracy. Surprisingly, our result reveals that AOA measurements obtained by wideband antenna arrays do not further improve position accuracy beyond that provided by TOA measurements.