Fundamental Limits of Wideband Localization Accuracy via Fisher Information

Determination of position accuracy for geolocation is a fundamental issue in wireless sensor networks. This paper derives the position error bound (PEB), a fundamental limit for localization accuracy, by using information inequality. In particular, the authors consider all multipath propagation parameters, and hence our bound is tighter than those of previous work. To alleviate computation complexity, the authors put forth the notion of equivalent Fisher information (EFI) to characterize the localization accuracy. This approach also unifies the contributions from line-of-sight (LOS), non-line-of-sight (NLOS), and a priori knowledge to the PEB in a consistent form. These results are applicable to ultra-wide bandwidth (UWB) systems as a specific case.