New ISAC scheme keeps drone-to-ship beams locked despite wave-induced motion

A new research paper from Rui Zhang and colleagues tackles a critical challenge in sea-air communication: maintaining a stable beam between an uncrewed aerial vehicle (UAV) and an uncrewed surface vehicle (USV) under constant wave-induced motion. The proposed solution leverages Integrated Sensing and Communication (ISAC) to simultaneously track the USV's three degrees of freedom—surge, sway, and yaw—while communicating. The team introduces a wide and narrow beam switching scheme based on sub-array selection. A wide beam mode covers the entire USV for robust state sensing, while a narrow beam mode uses that estimated state for high-gain communication with the USV's communication receiver (CR). To handle the complex dynamics, they derive a sea-air state evolution model that incorporates sea-induced disturbances and sea clutter as measurement noise. An extended Kalman filter (EKF) predicts and estimates the CR state, and a time allocation optimization problem adjusts how long the system stays in wide beam mode to maximize tracking accuracy.

The simulation results show that the proposed ISAC scheme achieves significantly higher tracking accuracy than state-of-the-art benchmark schemes, even under challenging sea clutter conditions. The paper, submitted to arXiv in June 2026, spans 13 pages with 11 figures detailing the system model, beam switching logic, and performance gains. By combining sensing and communication into a single framework, this work offers a practical path toward robust autonomous operations in maritime environments—where reliable drone-to-ship links are essential for surveillance, cargo delivery, and search-and-rescue missions. The authors note that future work could extend the model to multi-UAV scenarios or incorporate adaptive beamforming to further reduce latency.