Exploring L_p-Norm Regularization for TOA Localization in Asynchronous Networks Under Mixed LOS/NLOS Conditions

Ground-based stations are essential for terrestrial communication and positioning networks. They provide precise ranging and synchronization for resilient positioning, navigation, and timing (PNT) systems. However, in complex propagation environments, time-of-arrival (TOA) positioning is often degraded by non-line-of-sight (NLOS) propagation and clock offset, which are strongly coupled and difficult to mitigate jointly. In this study, TOA positioning in LOS-dominant mixed LOS/NLOS asynchronous scenarios is investigated. The proposed approach formulates asynchronous TOA localization as a joint estimation problem of sparse NLOS biases and clock offset under Lp regularization (0< p< 1) , which is efficiently solved through SDP relaxation and an iterative reweighting procedure. Simulation results demonstrate that the proposed method significantly improves localization accuracy under LOS-dominant mixed LOS/NLOS conditions, thus offering an effective solution for high-accuracy localization in asynchronous PNT networks.