Location accuracy of an UWB localization system in a multi-path environment

In this paper, we analyze the achievable location accuracy of a wireless localization system using pulse arrival time measurements of ultra-wideband (UWB) pulses. We briefly review the limits on the ranging accuracy given the regulatory constraints of UWB emissions and the parameters of the UWB transceiver hardware used for the localization system. We show that the accuracy of the arrival time measurements does not depend on the pulse spectrum in a very small measurement interval equal to half the inverse of the pulse center frequency. For measuring the arrival time outside this (usually tiny) measurement interval, we show that the measurement accuracy declines considerably and that it furthermore depends on the pulse bandwidth. We also show why short transmit pulses are necessary in a multi-path radio frequency channel to maintain an acceptable accuracy of the pulse arrival time.