Performance Analysis for Heterogeneous Air-Ground ISAC in Coordinated Multipoint Networks

The emergence of the $\mathit{\text{low-altitude}}\mathit{\text{economy}}$ (LAE) calls for highly integrated and reliable wireless systems that can simultaneously support $\mathit{\text{communication}}\mathit{\text{and}}\mathit{\text{sensing}}$ (C&S) functions. Although $\mathit{\text{integrated}}\mathit{\text{sensing}}\mathit{\text{and}}\mathit{\text{communication}}$ (ISAC) has been widely studied, most existing works focused on link-level or single-cell architectures in terrestrial environments, leaving the potential of network-level cooperative air-ground ISAC largely unexplored. To bridge this gap, a heterogeneous air-ground ISAC network architecture based on $\mathit{\text{coordinated}}\mathit{\text{multipoint}}$ (CoMP) is proposed, which incorporates a cooperative hybrid mono/bi-static sensing scheme to enhance spatial diversity and sensing capability. In the proposed architecture, a two-tier $\mathit{\text{base}}\mathit{\text{station}}$ (BS) deployment is adopted: master BSs are arranged in a hexagonal lattice, while slave BSs follow a Poisson point process distribution. This structure concurrently supports communication for terrestrial users and sensing for aerial targets. A holistic performance analysis framework for both C&S is further developed, accounting for key channel and network parameters. Simulation results reveal inherent trade-offs between C&S performance, especially under multi-BS cooperation and varying network density. These findings provide practical guidance for the deployment of scalable and efficient ISAC networks in LAE scenarios.