Gholami, M. R.Gezici, SinanStröm, E. G.2018-04-122018-04-1220161051-2004http://hdl.handle.net/11693/36850This manuscript studies the positioning problem based on two-way time-of-arrival (TW-TOA) measurements in semi-asynchronous wireless sensor networks in which the clock of a target node is unsynchronized with the reference time. Since the optimal estimator for this problem involves difficult nonconvex optimization, two suboptimal estimators are proposed based on the squared-range least squares and the least absolute mean of residual errors. We formulate the former approach as an extended general trust region subproblem (EGTR) and propose a simple technique to solve it approximately. The latter approach is formulated as a difference of convex functions programming (DCP), which can be solved using a concave–convex procedure. Simulation results illustrate the high performance of the proposed techniques, especially for the DCP approach. © 2016 Elsevier Inc.EnglishClock imperfectionConcave–convex procedureConvex optimizationPositioningTrust region subproblemsTwo-way time-of-arrival (TW-TOA)Article10.1016/j.dsp.2016.07.023