A Markov-chain Model of the DVB-S2 Forward Link for Cross-Layer Analysis

Kurzfassung

In order to quickly develop new cross layer algorithms and techniques and to study the application of these cross-layer solutions, it is necessary to be able to simulate the packet-layer behaviour of the channel in a quick and reliable way. Within this paper it is shown how the DVB-S2 forward link can be abstracted by using a Markov chain model. It is described how this Markov chain can be used to model the transitions of the used combinations of modulation and coding in DVB-S2 over time, and results for these transition probabilities are presented. The simulator which was developed in this work uses several well chosen input parameters, such as the transition probabilities, fade durations and error probabilities. These input parameters are computed from SNIR traces which are generated by an SNIR channel simulator developed at DLR. Finally the paper shows how well the results of the abstract model implemented in the simulator match with the results obtained from the SNIR traces.