UniSDM Proof of Concept: A Multimode Software Defined Modem for Underwater Communications

This paper presents a proof-of-concept for the UniSDM architecture, which is capable of simultaneously operating across acoustic, optical, magnetic induction, and RF communication modes. A flexible firmware stack is developed that integrates the logic for modem operation and supports multiple underwater communication modes mentioned above and the protocols and standards such as OFDM and JANUS for acoustics, as well as OFDM, single carrier, and IRDA-like protocols for optical communication. Additionally, it provides various interfaces, including a socket-based API, Ethernet tun-neling, and a graphical user interface (GUI). The firmware architecture incorporates cross-layer frame and waveform processing, enabling advanced communication paradigms such as multimode cooperative MIMO.