Channel estimation and physical layer adaptation techniques for satellite networks exploiting adaptive coding and modulation

The exploitation of adaptive coding and modulation techniques for broadband multi‐beam satellite communication networks operating at Ka‐band and above has been shown to theoretically provide large system capacity gains. In this paper, the problem of how to accurately estimate the time‐variant channel and how to adapt the physical layer taking into account the effects of estimator errors and (large) satellite propagation delays is analyzed, and practical solutions for both the forward and the reverse link are proposed. A novel pragmatic solution to the reverse link physical layer channel estimation in the presence of time‐variant bursty interference has been devised. Physical layer adaptation algorithms jointly with design rules for hysteresis thresholds have been analytically derived. The imperfect physical layer channel estimation impact on the overall system capacity has been finally derived by means of an original semi‐analytical approach. Through comprehensive system simulations for a realistic system study case, it is showed that the devised adaptation algorithms are able to successfully track critical Ka‐band fading time series with a limited impact on the system capacity while satisfying the link outage probability requirement. Copyright © 2008 John Wiley & Sons, Ltd.