  In this paper, we consider the channel modeling of a heterogeneous vehicular
integrated sensing and communication (ISAC) system, where a dual-functional
multi-antenna base station (BS) intends to communicate with a multi-antenna
vehicular receiver (MR) and sense the surrounding environments simultaneously.
The time-varying complex channel impulse responses (CIRs) of the sensing and
communication channels are derived, respectively, in which the sensing and
communication channels are correlated with shared clusters. The proposed models
show great generality for the capability in covering both monostatic and
bistatic sensing scenarios, and as well for considering both static
clusters/targets and mobile clusters/targets. Important channel statistical
characteristics, including time-varying spatial cross-correlation function
(CCF) and temporal auto-correlation function (ACF), are derived and analyzed.
Numerically results are provided to show the propagation characteristics of the
proposed ISAC channel model. Finally, the proposed model is validated via the
agreement between theoretical and simulated as well as measurement results.
