Clock Rigidity and Joint Position-Clock Estimation in Ultrawideband Sensor Networks
Ruixin Wen, Eric Schoof, Airlie Chapman
Abstract
Joint position and clock estimation are crucial in many wireless sensor network applications, especially in distance-based estimation with time-of-arrival (TOA) measurements. In this work, we study the graph properties under which an ultrawideband sensor network is localizable and clock synchronizable with one round TOA-based timestamp measurements. A novel clock rigidity theory is proposed and its topological condition is proved to have a close relationship to bearing rigidity. Based on clock rigidity, a graphical approach for analyzing the joint position and clock problem is investigated. It is shown that a position-clock framework with certain graph properties can be uniquely determined up to some trivial variations corresponding to both position and clock parameters. Simulation results are presented to demonstrate how clock rigidity theory is exercised in clock estimation and joint position-clock estimation.