A study on SNR estimation algorithms for channel state estimation in Communication Satellite Systems employing Fade Mitigation Techniques

Channel state estimation is one of the key processes carried out at the physical layer of Satellite Systems employing Fade Mitigation Techniques such as Adaptive Coding and Modulation (ACM). An accurate and reliable channel estimate is needed to fully realize the capacity gains accrued by using ACM. In this paper the SNR estimation algorithms, which perform the role of channel state estimators, are analysed from a system point of view to get a quantitative idea on the number of received symbols needed to get a reliable estimate, and the impact of interference noise on it. A DVB type satellite system has been investigated for the study. An improvement over the Maximum Likelihood (ML) estimator using Bayesian principles is suggested and illustrated.