Adaptive Transmission Techniques for Mobile Satellite Links
Adapting the transmission rate in an LMS channel is a challenging task because of the relatively fast time variations, of the long delays involved, and of the difficulty in mapping the parameters of a time-varying channel into communication performance. In this paper, the authors propose two strategies for dealing with these impairments, namely, Multi-Layer Coding (MLC) in the forward link, and open-loop adaptation in the return link. Both strategies rely on physical-layer abstraction tools for predicting the link performance. They will show that, in both cases, it is possible to increase the average spectral efficiency while at the same time keeping the outage probability under a given threshold.