Joint placement and communication optimization of uav base stations in GPS-denied environments

There has been a recent increase in the studies on integrated sensing and communication (ISAC) technology within unmanned aerial vehicles (UAVs). In our paper, we propose a UAV base station (BS) localization method under aerial global positioning system (GPS) jammed environments, where the UAV-BS simultaneously provides communication service to user equipments (UEs) on ground. Unaffected UEs are utilized as reference anchor nodes to position UAV-BS to a near optimal location. Studying UAV deployment in environments where GPS access in unavailable is crucial due to the susceptibility of UAVs to GPS jamming, which poses a potential risk of inaccuracy for ISAC systems. We jointly optimize UAV-BS communication performance and localization accuracy in terms of transmission power, root mean square error (RMSE), and position dilution of precision (PDOP). Further, we introduce three different algorithms to select the optimal set of reference nodes for accurate UAV-BS localization. Nodes are selected based on relative UE positions and different geometric configurations they form. Simulation is conducted for different UE distribution scenarios and results confirm that our proposed scheme can optimize the communication power and localization performance of UAV-BS under different PDOP constraints.