Uplink Single-Snapshot Frugal SLAM in Phase-Coherent Distributed MIMO Systems

We consider uplink frugal simultaneous localization and mapping (SLAM) in phase-coherent distributed MIMO (D-MIMO) systems, where a network of spatially separated single-antenna access points (APs) coherently receives narrowband, single-snapshot pilot signals from a single-antenna user equipment (UE). In contrast to existing phase-coherent localization and SLAM methods that rely on wideband measurements and/or multi-antenna APs, the proposed frugal setting operates with the minimum possible localization resources: a single subcarrier and a single snapshot at each single-antenna AP. In this paper, we formulate phase-coherent frugal SLAM as a coherent imaging problem, constructing a spatial image over a region of interest by treating the distributed AP observations as coming from a large synthetic aperture. Based on the coherent image, we develop a detection and localization framework that jointly identifies the UE, reflective surfaces, and scatterers. Simulation results validate the proposed framework and provide insights into the impact of grid resolution and off-grid error on detection and localization performance.