Planning of Advanced SatCom Systems Using ACM Techniques: The Impact of Rain Fade

This contribution presents a simplified approach to the planning of the space-segment resources of an advanced SatCom system using ACM (Adaptive Coding and Modulation) with the aim of evaluating the impact of rain fade on space resource planning. Specifically, the MultiEXCELL model is used as a means to include the spatial variability of rainfall, and is applied to the uplink path of the return link of the reference system. Taking into account the population density of the region of interest (western Germany), it is possible to derive useful information (average values as well as statistics) on the number of users that could not be served due to deep fades, on the users simultaneously requesting the same Modulation and Coding (MC) combination and on the number of carriers per MC that would be necessary to guarantee that all the customers can be provided with the minimum agreed long-term throughput under full network load. The results indicate the usefulness of such an approach in planning the resource required by an ACM-enabled system, which would be strongly over-dimensioned if only classical point statistics of total tropospheric fade were considered