The Coupling Effect of Sensing Targets on the Environment for 3GPP ISAC Channels: Observation, Modeling, and Validation

TL;DR

This paper presents a new ISAC channel model that captures the complex coupling effects of sensing targets with environmental scatterers, validated through measurements at 105 GHz, improving accuracy in indoor scenarios for 6G applications.

Contribution

It introduces a coupled ISAC channel model with novel parameters BR-CF and FS-CF, validated against real measurements, enhancing modeling accuracy for sensing target interactions.

Findings

The model accurately captures power variations caused by the sensing target.

Validation shows higher similarity with measured data than non-coupled models.

The framework supports improved design of ISAC systems in complex environments.

Abstract

Integrated Sensing And Communication (ISAC) has been identified as a key 6G application by ITU and 3GPP, with standardization efforts already underway. Sensing tasks, such as target localization, demand more precise characterization of the sensing target (ST) in ISAC channel modeling. The ST couples complexly with environmental scatterers, potentially blocking some multipaths and generating new ones, resulting in power variations compared to the original channel. To accurately model this effect, this paper proposes a coupled ISAC channel model based on measurements and validates it through similarity analysis between simulated and measured channels. In this work, we first conduct ISAC channel measurements in an indoor factory scenario at 105 GHz, where the multipath power variations caused by the ST's interaction with the environment are clearly observed. Then, we propose an ISAC channel modeling framework that incorporates two novel parameters: the Blockage-Region Coupling Factor (BR-CF) and the Forward-Scattering (FS)-CF, which characterize the spatial region and intensity of the coupling effect, respectively. Finally, the proposed model is validated through similarity comparison with measured data, demonstrating higher accuracy for both LoS and NLoS scenarios compared to the non-coupled model. This realistic ISAC channel model provides an effective framework for capturing the ST-environment coupling effect, supporting the design and evaluation of ISAC technologies.