Design of Underwater Software Acoustic Modem (USAM) for the Applications of Acoustic Data Communication

The advent of the Autonomous Underwater Vehicle (AUV) has revolutionized the field of underwater navigation and surveillance. The AUV now is programmed to follow a predefined route, although communication to navigate the vehicle would be preferable. This paper deals with an implementation of a sound card, as an Underwater Software Acoustic Modem (USAM), which allows the system to reduce complexity and increase robustness in a time-variant underwater environment by using PC Sound card as it mitigates the conventional DSP Processors. The fundamental principle of USAM is to perform the maximum processing of MODEM operations in software rather than hardware. The entire functionality of the transmitter/receiver processing part of the modem is implemented through software and then the existing sound card of the computer is utilized as `Analog to Digital' and `Digital to Analog' converter. The sound card is then interfaced with the underwater telephone set to use the underwater channel as a physical medium for communication.