Sahinoglu, Z.Gezici, Sinan2016-02-082016-02-0820100536-1486http://hdl.handle.net/11693/28558Date of Conference: 23-27 May 2010Two-way time-of-arrival (TW-ToA) is a widely used ranging protocol that can provide the distance between two devices without time synchronization. One drawback of the TW-ToA is poor positioning accuracy in the absence of a sufficient number of reference ranging devices. Also, for a self-positioning system with a limited battery life, it might be necessary to limit the number of transmissions while satisfying accuracy constraints. In this paper, a cooperative positioning protocol [1] is studied, which can improve positioning accuracy compared to the conventional TW-ToA based positioning systems and also facilitate positioning with fewer packet transmissions; hence, it can prolong battery life on average. The maximum likelihood estimator is obtained for the cooperative technique and the limits on the positioning accuracy are quantified in terms of the Cramer-Rao lower bound (CRLB). Simulation results are provided in order to show performance improvements. ©2010 IEEE.EnglishCooperative positioningCramer-Rao lower bound (CRLB)Maximum likelihoodTime-of-arrival (ToA)Battery lifeCooperative positioningCramer-rao lower boundMaximum likelihood estimatorNode cooperationPacket transmissionsPerformance improvementsPosition estimationPositioning accuracyPositioning systemSelf-positioningSimulation resultTime synchronizationTime-of-arrivalCramer-Rao boundsMaximum likelihood estimationConference Paper10.1109/ICC.2010.5502319