Antenna diversity and GSE-based packet level FEC for DVB-S2 Systems in Railway scenarios

Abstract

In this paper, we address the study of a broadband satellite system based on DVB-S2 for interactive services in a mobile scenario. In particular, we focus on the railway scenario when the train is moving with high speed under LOS (Line of Sight) conditions considering also the atmospheric effects for Ku band. We aim at the design of fading countermeasure to compensate the impact of short and medium term fading that is present in the LOS case, which is owed to the speed, the near environment (modelled by a Rice model) and the power arches. Long term signal blockage due to e.g. railway tunnels has not been considered in this study. With the purpose of compensating for these effects, the use of packet-level FEC and antenna diversity has been already proposed. In this paper, a further development of packet-level FEC, in combination or not with antenna diversity, is proposed. We propose a coding that differentiates classes of service thus avoiding guaranteeing quasi-error free PER performance for applications that do not need it with the consequent gain in capacity. Furthermore, we consider the adaptation layer to be based on the novel GSE (Generic Stream Encapsulation) encapsulation method currently under standardization process. Our results show that our proposed fade mitigation techniques yield improvements of average packet error rate.