Cognitive Beamhopping for Spectral Coexistence of Multibeam Satellites

The usable satellite spectrum is becoming scarce due to continuously
increasing demand for broadcast and multimedia services. In this context, we consider
the problem of enhancing spectral efficiency in multibeam satellite networks.
The spectral coexistence scenario of two multibeam satellites over a common coverage
area is studied with a primary satellite having larger beams and a secondary
satellite having smaller beams. Furthermore, a novel cognitive beamhopping satellite
system is proposed. The system performance of the proposed system is evaluated and
compared with that of conventional multibeam and beamhopping systems in terms
of system throughput. It is shown that the proposed system significantly enhances the
spectral efficiency in comparison to other systems. Moreover, the scenario of the presence
of multiple secondary users within an inactive primary beam is considered with
power control on the secondary transmission. The system performance is evaluated
by considering partial and full frequency sharing approaches. It is noted that the total
spectral efficiency increases with the number of secondary users in the full frequency
reuse approach.