DIGITAL SELECTIVE CALLING (DSC) - DSP BASED SOFTWARE RADIO FOR THE GLOBAL MARITIME DISTRESS AND SAFETY SYSTEM (GMDSS)

The US and European Coast Guard have begun offering a new radiotelephone service to mariners called Digital Selective Calling (DSC) as part of the new Global Maritime Distress and Safety System (GMDSS). DSC is a brand new technology to make the coastal communication save and automatic. In cooperation with Frequentis Nachrichtentechnik GesmbH, Vienna we develop a real-time software radio which allows to send and receive various calls on multiple channels. The technical solution will comprise the following features : • Our equipment consists of the Blue Wave Systems PCIC6600 board with 2 TMS325C6x processors and a 16-input, 8-output I/O card. • The first DSP has the functionality of a DSC radio station. A new adaptive algorithm realizes a very stable, non-linear FSK demodulation, operating down to low signal-to-noise ratios. • The second DSP realizes a time and protocol triggered FSK modulation with the possibility to simulate different channel disturbances. • The DSP operation will be supported by a small dataflow oriented real-time operating system and a simulink-like Graphical User Interface, which hide the complex asynchronously buffered communication between host and DSP, and support online reconfiguration and performance monitoring. Our DSP solution is a new combination of a software radio and a compliance tester. The prototype is planned to be tested in 9 Norwegian coastal radio stations.