Multiuser Localization with Leaky Wave Antennas

The increasing demands expected from future generation of wireless networks have driven interest in exploiting the terahertz (THz) frequency range. Two core challenges associated with harnessing the large bandwidth available at THz are the need for accurate localization to handle harsh propagation, and the difficulty in designing cost- and power-efficient antenna arrays operating in such bands. In this work, we explore multiuser localization using an emerging THz technology based on leaky wave antennas (LWAs). LWAs are highly cost-effective, and can enable frequency-dependent beam steering with a single element through passive radiation leakage, which can be exploited for localization. We develop a physics-compliant signal model for LWA-based multiuser localization and introduce two localization algorithms: a maximum likelihood-based estimator with exponential complexity, and a low-complexity spectral correlation-based method tailored to LWA properties. Additionally, we derive the Cramér-Rao bound for angle-of-arrival estimation with LWAs. Numerical results demonstrate that the proposed methods achieve accurate multiuser localization, rivaling and even surpassing conventional costly array-based approaches, while significantly reducing implementation costs and complexity at THz bands.