Applicability of Fade Mitigation Techniques to Mobile DVB-S2/RCS Satellite Systems: Accent on Railway Scenario

摘要

This paper addresses the applicability of Fade Mitigation Techniques (FMTs) to mobile DVB-S2/RCS based broadband interactive satellite systems. Emphasis is put on the railway scenario, where quite a few pilot projects and demonstration initiatives have already been launched and even (pre-) commercial activities have already commenced. A useful methodology to transform rain fading statistics from a fixed to a mobile satellite communication system is described. Particular attention is paid to the second order rain fading statistics and, specifically, to the rain fade slope, whose accurate knowledge is essential to the design and performance of the FMT control loop. The FMT control loop margin required due to mobility is estimated in Line-of-Sight (LOS) conditions for different train speeds and rain attenuation levels. In addition, the impact of non-LOS effects, such as long blockages due to tunnels, on the performance of FMT control loop is examined and the possible use of short-term rain fade prediction methods is analyzed. Numerical results obtained through computer simulations are provided and useful conclusions are drawn.