This is a past event.

Zhaohui Wang, PhD

Assistant Professor, Electrical and Computer Engineering

Seminar Talk: Signal Processing and Machine Learning for Underwater Acoustic Communication Networks 

Abstract: 

Underwater wireless communication networks are the enabling techniques for unmanned, in situ and real-time aquatic monitoring and data collection in a wide range of applications, such as scientific studies, pollution detection, offshore oil and gas drilling, and tactical surveillance. Due to the high attenuation of radio waves in water, acoustics has been a major information carrier for underwater transmissions. However, the underwater environment poses grand challenges for acoustic communications and networking, such as the high spatiotemporal dynamics of underwater acoustic channels, the abundance of interferences, the limited frequency band for long-range transmissions, and the large sound propagation latency. Consider the lifespan of underwater systems that varies from a few years to decades. We envision an online-learning-based framework for underwater acoustic communications and networking, where the underwater acoustic system 1) models and predicts the long-term dynamics of the acoustic environment, and 2) proactively adapts its communication and networking strategy to the dynamics of the environment, thereby maximizes the long-term system performance.

In this talk, we will first present our observations of underwater acoustic channel dynamics in a series of field experiments that were conducted in nearby lakes during both open-water and ice-covered seasons. Then, we will explore signal processing techniques to model and predict underwater acoustic channel dynamics at multiple scales. Through forecasting the underwater channel dynamics, efficient acoustic communication and networking strategies can be developed. In the online-learning-based framework, the tradeoff between the acoustic environment exploration and exploitation will be tackled via Bayesian reinforcement learning techniques, which provide a principled approach to weighing the immediate reward of a communication and networking strategy and its associated long-term benefit of revealing the environment’s dynamics during acoustic communications. At the end of the talk, we will give a brief description of an underwater testbed system developed in our research group, which has been serving as an excellent platform for both undergraduate and graduate education.