Object-Oriented Integrated Sensing and Communications (ISAC) Channel Modeling for Low-Altitude 3D Spaces

Abstract

This paper presents a novel framework for object-oriented integrated sensing and communications (ISAC) channel modeling in urban environments over low-altitude 3D space, which jointly considers unmanned aerial vehicle (UAV)-based and ground-level measurements in conjunction with ray-tracing (RT) technology. Two types of object-oriented channels are considered, namely the static background channel, e.g., buildings, and the dynamic channel, e.g., cars and UAVs. Firstly, a systematic measurement campaign was conducted in the 4 GHz band at 80 m height using a UAV and at ground level using a vehicle. Additionally, photographs of the measurement area are taken by the UAV for an object-oriented 3D model. Based upon channel measurement data and employing RT techniques, the EM parameters of the considered coverage area are accurately calibrated and validated at both heights. This has allowed us to obtain accurate simulations across the vertical airspace of both sensing- and communication-background channels, followed by a comprehensive channel characteristics analysis. By subtracting the background channel from the dynamic channel, experimental results have demonstrated that the angle and distance information of objects can be accurately estimated. Through a case study, it has been shown that the acquired prior scene information can be utilized as a reference to improve object-oriented coverage.