SDR Underwater Acoustic Communication System (May 2020)

Scrolling through a Twitter feed, liking a picture, or texting a friend—everything feels so natural and effortless by today’s standards. All this is made possible by radio waves silently carrying information through the air, a technology most of us take for granted—until it stops working.

Underwater, however, it’s a whole different story. Radio waves don’t travel well through water, so from the moment humans began exploring the ocean’s depths, we relied on sound waves for communication. Early systems used analog acoustic signals to transmit speech underwater—a method still used in submarine communication today.

But analog signals are far from perfect. They’re hard to hear clearly underwater and not very reliable. Enter digital communication. When digital technology emerged, it quickly transformed underwater acoustic systems, making them more robust and capable.

Still, the shift to digital wasn’t enough. Even with specialized chips enabling underwater communication, they come with limitations. Today, with increased computing power, we can process and demodulate signals faster and adapt systems more flexibly—whether it’s tweaking CRC algorithms, modulation schemes, or protocols.

And here’s the beauty of it: software-driven solutions allow for easy updates, unlike hardware which can be costly and cumbersome to replace. That’s why I firmly believe the future of communication systems, especially underwater, lies in software.

Testing my acoustic radio in a bathtub.

Link to Digital Commons