Advances in Underwater Signal Processing and Communication: Challenges, Innovations, and Applications

Dear Colleagues,

Underwater signal processing and communication technologies play a crucial role in a wide range of applications, including marine exploration, environmental monitoring, underwater resource mapping, disaster response, and defense operations. The complex and dynamic nature of the underwater environment presents significant challenges, such as signal attenuation, multipath propagation, and the absence of GPS, necessitating advanced signal processing techniques and robust communication systems.

Key challenges and research directions in this field include the following:

• Accurate Positioning and Navigation: In GPS-denied underwater environments, technologies such as acoustic localization, inertial navigation systems (INSs), simultaneous localization and mapping (SLAM), and SONAR-based navigation are essential for precise underwater positioning. 
• Reliable Communication: Underwater communication relies on acoustic, optical, and electromagnetic methods, each with its own trade-offs. Innovations in modulation techniques, adaptive transmission, and hybrid communication strategies are critical for improving data transmission reliability. 
• Real-Time Data Processing: Autonomous underwater systems, including unmanned underwater vehicles (UUVs) and sensor networks, require the real-time processing of sensor data for adaptive decision making, target recognition, and environmental modeling. 
• Noise Reduction and Signal Enhancement: Underwater environments introduce challenges such as multipath interference, Doppler effects, and background noise. Advanced filtering, beamforming, and machine learning-based noise reduction techniques are vital for improving signal clarity. 
• Energy-Efficient Systems: Long-duration underwater operations demand energy-efficient signal processing and communication methods to maximize operational lifetime, particularly for deep-sea exploration and long-term environmental monitoring. 
• SONAR-Based Sensing and Imaging: SONAR technologies, including multibeam SONAR and synthetic aperture SONAR (SAS), are widely used for underwater mapping, object detection, and marine habitat assessment. Advanced signal processing techniques enhance SONAR resolution, reduce interference, and improve target classification. 
• AI and Machine Learning for Underwater Systems: The integration of AI into underwater signal processing enables intelligent decision making, anomaly detection, and predictive maintenance for various applications, from autonomous navigation to underwater surveillance.

This Topic aims to explore cutting-edge innovations in underwater signal processing and communication, bringing together experts from diverse fields such as signal processing, telecommunications, robotics, oceanography, and environmental science. By addressing these challenges, advancements in this field will contribute to improved underwater exploration, scientific research, industrial applications, and defense capabilities.

Prof. Dr. Jaehak Chung
Dr. Hojun Lee
Dr. Yongcheol Kim
Topic Editors