Capacity analysis of multibeam joint decoding over composite satellite channels

The throughput of current multibeam satellite systems is limited by self interference. Interference mitigation techniques have the potential to significantly increase the spectral efficiency of these satellite communication systems. The present contribution investigates the ergodic capacity of the return link of a multibeam satellite system, where full frequency reuse is employed and user signals are jointly processed at the gateway. The proposed model incorporates correlated satellite antennas over Rician channels which represent some inherent characteristics of satellite communications. Additionally, the effects of shadowing caused by user mobility, are modeled via the lognormal distribution. Hence, a composite Rician/lognormal fading channel with fully correlated receive antennas is considered. For this channel, a new lower bound on the ergodic capacity is analytically deduced and verified through simulations.