Summary
This paper tackles the challenge of understanding how wireless signals bounce off different moving objects like robots, people, and cars. The authors recorded nearly 117,000 signal measurements at 28 GHz from many angles and positions to capture how these objects scatter signals. They created a channel model that links physical positions on each target to groups of signal paths, describing signal behavior with both precise geometry and random variation. Their model matches real-world data well and can be used to simulate or design systems that combine communication and sensing.
What this means in practice
- •For wireless system designers: Simulate and predict signal behavior around robots, humans, and cars for integrated communication and sensing applications at 28 GHz.
- •For automotive radar engineers: Improve the accuracy and reliability of radar systems by using measurement-based channel models that account for realistic vehicle and pedestrian scattering.
Authors
Neeraj Varshney, Jelena Senic, Jack Chuang, Samuel Berweger, Steve Blandino, Jian Wang, Camillo Gentile, Nada Golmie
Abstract
This paper develops a channel model for scattering from a broad class of integrated sensing and communication (ISAC) targets-robots, humans, and automobiles-based on a unified measurement campaign at 28~GHz. Nine targets are characterized from numerous transmitter--receiver configurations per target, spanning full bistatic and aspect angles and thus covering backward to forward scattering. Repeated acquisitions are collected for each configuration to capture target motion and dynamics, yielding nearly 117\,000 acquisitions in total. Measurements are collected with a 2~GHz-wide channel sounder equipped with a 256-element phased-array antenna, followed by digital beamforming and super-resolution processing for reliable extraction of multiple paths in delay and 2D angle, with average estimation errors of 0.1~ns and 0.2$^\circ$ respectively. From these measurements, we reduce a \emph{path-specific} channel representation in which the scattering is modeled as a cluster of paths whose center is defined by the bistatic specular \emph{geometry}; the cluster shape is described \emph{stochastically}. To ensure physically grounded spatio--temporal consistency, extracted paths are mapped to incident points on the target, each with an associated radar cross section (RCS) that is compatible with the 3GPP TR~38.901 ISAC channel model, and are subsequently mapped back to path properties for channel synthesis. The resulting statistical distributions are well behaved, physically interpretable, and consistent across targets, geometries, and motion. Comparison between measured and synthesized channel realizations demonstrates close agreement in pathloss trends and fluctuation behavior. Together, these results yield a high-fidelity, measurement-derived channel representation suitable for ISAC simulation, target modeling, and system design.