A Scatterer-based Hybrid Channel Model for Integrated Sensing and Communications (ISAC)

In this paper, we propose a scatterer-based hybrid channel model framework for integrated sensing and communication (ISAC). The basic idea of the scatterer-based ISAC channel model is to first generate scatterers in the propagation environment and then use simplified ray-tracing to generate both communication and sensing channels. The proposed model is hybrid in the aspect of scatterers i.e., the scatterers consists deterministic part and stochastic part. The deterministic part of the scatterers is from the input environment geometry while the stochastic part is constructed from the stochastic MPCs generated by 3GPP channel standardization framework. A method to couple the stochastic scatterers with the input environment geometry is proposed to avoid unrealistic ray propagation. To support the proposed ISAC channel model in the application of THz communications, we conduct RCS measurement campaigns with common building materials for developing deterministic propagation models at 140 GHz. Also, we conduct communication and sensing channel measurement campaigns in both indoor and outdoor scenarios for extracting fast-fading parameters for 3GPP channel standardization framework. The simulation results show that the proposed model has the capability of characterizing ISAC channel properties and validate with the measurement results.