Signal Detection and Noise Modeling of a 1-D Pulse-Based Ultra-Wideband Ranging System and Its Accuracy Assessment

In this paper, we estimate the achievable localization error in an ultra-wideband (UWB) precise positioning system. The system is based on the time difference of arrival of narrow pulses to a multitude of base-stations. A mathematical model and simulation platform are developed to describe the behavior of the UWB indoor localization system. Limits on the location accuracy as a function of the parameters of the UWB system are described. A discussion of the dominant errors is presented including picosecond pulse generator jitter, sampling clock jitter, sampling rate, and system additive white Gaussian noise. We show a simple method to calculate the total system jitter, and describe error biasing phenomenon as the tag moves, approaching one base-station and moving away from another. Design curves are provided to determine the required specifications of the various system components to achieve a certain positioning accuracy.