A TDOA measurement technique for asynchronous indoor localization system using UWB-IR

Abstract

In this paper we have proposed a Time Difference of Arrival (TDOA) measurement scheme for practical asynchronous systems using low cost low power target nodes (called tags). The system performs localization of transmit only tags using an ultra wide band Impulse radio (UWB - IR). We use a known location reference node for synchronization between the receiving (or anchor) nodes. The clock of the reference node is considered to be a perfect clock whereas clocks of all other nodes, anchor nodes as well as target node, is assumed to imperfect. We formulated the equations to synchronize the clocks of the anchor nodes and estimate the TDOA range measurements between the anchor nodes. The equations were analyzed with the practical measurement results.