Affordable underwater acoustic communications

Overview

Communication is an enabling technology for underwater systems such as autonomous underwater vehicles (AUVs), sensor networks, and diver support equipment. These systems cannot use radio frequency (RF) links, because radio waves are heavily absorbed by water, and poor visibility rules out optical links. Only acoustic communication is suitable. The underwater acoustic channel is bandwidth-limited, slow, and degraded by multipath, Doppler, and noise, making underwater modems a demanding signal processing and embedded systems problem.

Commercial underwater modems exist but are expensive and closed-source, with prices ranging into the thousands or tens of thousands of dollars. This cost and lack of openness hampers their use in affordable products and research. Such cost is acceptable for high-end naval, offshore, and scientific platforms, but not for low-cost, small-scale, or expendable systems deployed in large numbers.
Motivated by this, this project will study and build an AHOI underwater acoustic modem, an open-source, low-power modem developed at Hamburg University of Technology (TUHH).

Research activities

The project will suit students interested in one or more of:

• acoustic and underwater channel modelling
• digital signal processing and modulation/demodulation,
  RF and analog front-end (amplifier, filter, transducer) design
• embedded hardware design,
  embedded software in C and assembly (STM32 / ARM Cortex-M)
• communication protocol design (MAC, ranging, and routing)
• continuous integration and test driven development systems.

Outcomes

Build an AHOI underwater acoustic modem, an open-source, low-power modem developed at Hamburg University of Technology (TUHH).

Skills and experience

Signal Processing, Telecomunications, embedded systems

Keywords

• underwater acoustic communications
• signal processing
• embedded systems

Contact

Dhammika Jayalath, Dhammika.Jayalath@qut.edu.au