A software-defined radio implementation of maritime AIS
Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2007.
SumbandilaSat is the second South African satellite, and is scheduled to be launched in April/May 2007. A software defined radio (SDR) automatic identification system (AIS) receiver is proposed as a possible experimental payload for this satellite. The AIS receiver can be used to track and store movement of ships at sea, and then forward this information to the ground station upon request. This thesis demonstrates the design of a SDR AIS receiver for Sumbandila satellite. The design of a GMSK/FMmodem as used in AIS is presented. Models are developed and simulated in Matlab. Digital signal processing algorithms developed for the AIS receiver are highlighted. Algorithms are developed to decode and translate the AIS encapsulated binary messages. The models are transferred to C++ and the AIS receiver is implemented on the SDR architecture. Finally the real time performance of the AIS receiver is presented along with some test results and performance analysis.