Micro-modem for short-range underwater communication systems

Small-scale underwater communication system, such as underwater wireless sensor network (UWSN), has been emerged as one of the promising research and development areas. For the use in limited inland waters, in this paper, we design and implement an underwater communication modem having the properties of small size, low-power consumption and moderate working distance and data rate. Channel impulse responses are investigated by means of both simulation and experiments in a pond and a lake in order to figure out the characteristics of underwater acoustics in confined aquatic spaces, and error performances are evaluated under several conditions. According to results, theoretical channel impulse responses are quite different from empirical ones due to shallow water depth and reflections by surrounding wall and aquatic ecosystem. Since the implemented micro-modem satisfies the requirements for short-range underwater communication systems, it could be utilized for various applications in underwater.