Effect of Path-Overlap on Localization Accuracy in Dense Multipath Environments

Accurate positioning is an essential issue in location- aware wireless networks. Wideband transmission is inherent suitable for indoor localization due to its potential of providing accurate range measurements. In this paper, we will investigate the effect of path-overlap phenomena on the localization accuracy, since wideband signals traveling between nodes in the network experience multipath propagation. The notion of equivalent Fisher information (EFI) is proposed and applied to derive the squared position error bound (SPEB), a measure of the localization accuracy. EFI unifies the contributions from individual anchors in a canonical form, i.e., a sum of ranging information (RI), which characterizes the ability of a received waveform for localization. We show that the effect of path-overlap on the RI can be quantified by the path-overlap coefficient. Our numerical results present the behaviors of the path-overlap coefficient for different propagation channels and transmitted waveforms.