Ultra-wideband localization with collocated receivers

Abstract-A three-dimensional (3-D) ultra-wideband time-ofarrival (TOA) localization scheme that employs a single cluster of receivers is studied in this paper. The receivers are placed in proximity (e.g., on a two-dimensional plane within a few decimeters), and thus it does not require wireless synchronization of the receivers. The optimum 3-D receiver placement in the sense of minimum estimation variance defined by the Cramér-Rao lower bound is analyzed. The position error bound as a function of the number of receivers and the distance between the source and the receiver unit is derived. A hardware and software prototype that works in the 3.1−