5 papers
Secure Pseudonymetry with DSSS Watermarking for LEO Satellites
Nisanur Camuzcu, Alireza Vahid
Low-Earth-orbit (LEO) constellations offer dense signals of opportunity (SOP) for positioning, navigation, and timing (PNT) without dedicated navigation infrastructure. However, us…
Near-Field User Location Inference From Far-Field Power Measurements
Shima Mashhadi, Tiep M. Hoang, Alireza Vahid
Near-field beamfocusing enabled by extremely large-aperture arrays (ELAA) is a promising 6G technique for massive connectivity and high spectrum efficiency. While beamfocusing conc…
Starlink Beacons for Passive LEO-Aided 9D Navigation
Nisanur Camuzcu, Tiep M. Hoang, Alireza Vahid
Global Navigation Satellite Systems (GNSS) underpin positioning, navigation, and timing (PNT), yet their low-power signals are easily blocked or disrupted, leaving gaps in PNT avai…
Mix-and-Conquer: Beamforming Design with Interconnected RIS for Multi-User Networks
Sajjad Nassirpour, Naoki Kusashima, Jose Flordelis +1
We propose a new reconfigurable intelligent surface (RIS) structure, referred to as interconnected RIS (I-RIS), which allows the RIS elements to be interconnected and share the inc…
Capacity-Maximizing Dynamic User Association in Double RIS-Aided Broadcast Networks
Alireza Vahid
We introduce an information-theoretic framework to dynamically pair up different reconfigurable intelligent surfaces (RISs) with wireless users with goal of maximizing the fundamen…