Cross layer link adaptation in time varying mobile satellite channels with statistical and outdated CSIT

The inherently large propagation delay present in satellite communications makes link adaptation procedures difficult to apply. Particularly, channel state information at the transmitter (CSIT) can be completely outdated after a round-trip time for high-speed receivers. For moderate speeds, some correlation is expected between the current channel and the CSIT. In this paper we present a link adaptation procedure that uses both CSIT and statistical information about the channel variation. We exploit the use of retransmissions to alleviate the rate backoff induced by the outage constraint. The link adaptation procedure is stated as the maximization of the throughput subject to a packet error probability constraint, and the channel variation is captured by a time-homogeneous Markov chain.