A novel channel model for UAV-to-ground links in integrated sensing and communication scenarios

Integrated sensing and communication (ISAC) is believed to play a crucial function in the sixth generation wireless communication networks. The channel model is a key element for optimizing and evaluating ISAC systems and technologies. In this paper, we propose a unmanned aerial vehicle (UAV)-to-ground ISAC channel model for low-altitude scenarios, providing a theoretical foundation for typical low-altitude ISAC applications such as unauthorized UAV target localization and invasion detection. The model captures both the non-stationarity induced by UAV motion and the intrinsic correlations between different channels. Firstly, to comprehensively characterize practical low-altitude scenarios that involve target UAVs, UAV terminals, and environmental objects, we model the ISAC channel as an integrated target and background channels. Specifically, the target channel encompasses all elements effected by the target UAV. The background channel includes other elements not belonging to the target channel. Secondly, the target channel is modeled as a concatenation of three components: the transmitter-target link, the target-receiver link, and the scattering response of the target UAV. To generate parameters of the target channel at both large and small scales, a concatenated approach is introduced. Additionally, a UAV-to-ground ISAC channel implementation framework is proposed to jointly generate the background and target channels. Finally, we performed measurements of the target UAV’s scattering response, deriving several key conclusions. Simulation results further validate the effectiveness of the introduced concatenated approach and the veracity of the proposed channel model.