A realization of the software defined radio concept in an underwater communication modem

The recent years increasing interest for research on underwater communication and networking has sparked the interest for a software defined modem (SDM). This concept has been realized on a sophisticated hardware platform, which is provided in form of the commercially available develogic Hydro-Acoustic Modem HAM.Base. This is a small sized, energy efficient, and deep water approved underwater communication modem. It provides widespread flexibility especially in the physical layer, but also broad accessibility to higher layers. Such an SDM is especially suitable for scientific research in underwater communication networks, where the implemented software architecture may be a result and not a prerequisite. This paper is about the tools, on how, and to what extent reprogramming and reconfiguration of this SDM are performable. As an example it is shown how this SDM is programmed to be used in the framework of TUWACS (Transient Underwater Acoustic Communication System) used in the robust acoustic communications in underwater networks (RACUN) EDA project.