Indoor Geolocation Distance Error Modeling using UWB Channel Measurements

In this paper we introduce a model for the distance error measured from the estimated time of arrival (TOA) of the direct path (DP) in a typical multipath indoor environment. We use the results of our ultra-wideband (UWB) measurement database in a sample office environment. To begin modeling, first we separate the causes of the error into multipath and undetected direct path (UDP), and then we model them separately considering the variation of bandwidth of the system. We show that the behavior of the distance error consists of two parts; one that is from multipath, and the other one from UDP. Both errors can be modeled as Gaussian, so the final distance error is a mixture of two Gaussian distributions. We also related the statistics of the distributions to the bandwidth of the system