RSS-Based Multiple User Terminal Localization With Unknown Propagation Parameters in 6G Application

Since distributed sensing, storage, and computing are the frontiers for future sixth-generation (6G) communication systems, user terminal (UT) localization based on received signal strength (RSS) data from wireless sensor networks (WSNs) has received widespread attention because of its low energy consumption and ease of operation. Most of the existing work focused on the single-source localization problem. However, multiple UT localization is a more realistic problem that has not been well addressed. In this paper, we proposed a novel multiple UT localization scheme. Specifically, based on the log-normal property of spatial shadowing, the RSS is approximated as a random variable obeying a log-normal distribution, and the objective function is derived via maximum likelihood estimation. Then, aiming to better solve the objective function, a radio map is constructed to narrow search area, and a meta-heuristic algorithm with global search capability is adopted. Compared with the state-of-the-art methods through simulation experiments, it is proved that the method proposed in this paper has the best localization performance.