Design and Implementation of an Underwater Telecommunication System
Nikolaos Baxevanakis
Abstract
This work presents the design and actual implementation of an underwater telecommunication system. We chose ultrasound waves as the wireless transmission technique, and analog AM modulation was picked for information encoding. To produce and receive the ultrasound wave, two underwater ultrasound transducers are used (Prowave® 200LM450), with a nominal frequency of 200kHz. The transmitter modulates the power supply of an H-Bridge to generate the needed AM signal, while the receiver is based on a superheterodyne block, with the aid of an automatic gain control (AGC) circuit. Carrier signals and the receiver's tuning are digitally implemented, to strengthen the system's reliability and flexibility. Necessary circuit simulations were carried out in LTSpice XVII®, while the completed system was put to test not only in the lab, but also in a 80-meter water tank.