Integriertes satellitengestütztes Multimedia System (L*IP)

Under contract by European Space Agency an advanced satellite communication system – L*IP is developed which provides efficient interconnection of local area networks with optimal utilization of the precious satellite capacity. In contrast to existing systems it provides fully meshed connectivity and supports the Internet protocol suite. Quality of service guaranties are also key issues of the project. In the frame work of this project the Institute develops an efficient multi-frequency TDMA-modem operating at bit rates up to 8 Mbit/s. Emphasis was put on reliable synchronisation at low signal to noise ratio. Turbo coding is applied as a new method to decrease the inherent error floor with minimum iterations, for which a patent was applied. Extensive simulations of the system have been performed in order to optimise the system performance. The implementation follows the “software radio” approach as far as possible, the modem is software defined. Time critical elements are implemented in FPGAs. The overall communications platform is based on Linux PCs ensuring the easy evolution of the system.