Enabling Spatial MIMO for Satellite Communications Without CSIT

Satellite Communications are proposed for supporting data traffic ubiquity at high data throughputs. Recent research works propose the use of MIMO precoding in multibeam satellites or in spatial MIMO architectures where multiple satellites transmit pointing to the same region at the same frequency. However, their implementation is subject to discussion because of the need for channel state information at the transmitters, the cooperation among gateways and/or satellites or the correlation among channel responses in a purely Line-of-Sight (LoS) environment. In this work, we aim to describing the implementation of blind interference alignment (BIA) in satellite networks. Beyond the obvious benefits of the open-loop transmission, i.e., a return link is not required for providing channel state information at the transmitters (CSIT), BIA offers additional benefits in comparison with MIMO precoding for satellite communications such as the independence of the achievable rate on the channel responses of the users or the lack of cooperation for data sharing while achieving multiplexing gain. Simulation results show that BIA outperforms precoding schemes in the medium SNR range. These results motivate further research lines such as the use of BIA in low earth orbit satellite constellations of the impact of hardware impairments introduced by reconfigurable antennas.