Inline Interference Mitigation Techniques for Spectral Coexistence of GEO and NGEO Satellites

The requirement of low latency for real time systems and high demand of broad-
band data are leading to the rapid deployment of Low Earth Orbit (LEO)/Medium
Earth Orbit (MEO) satellite systems in several frequency bands. When the number
of usable non-geostationary (NGEO) satellites i.e., LEO/MEO in space increases,
the need for frequency coexistence between the NGEO satellite systems with the
already existing geostationary (GEO) satellite networks increases rapidly. In this
context, it is crucial to explore interference mitigation techniques between GEO
and NGEO systems in order to allow their spectral coexistence. More specifically,
in the coexistence scenario of GEO and NGEO satellite networks, in-line interfer-
ence may be a serious problem and it arises whenever an NGEO satellite passes
through a line of sight path between a GEO earth station and a GEO satellite. In
this paper, we carry out interference analysis between GEO and NGEO systems
considering the case of O3b satellite systems and propose an adaptive power control
technique for both the uplink and the downlink coexistence scenarios in order to
mitigate the in-line interference. Furthermore, we provide several cognitive solu-
tions for mitigating the in-line interference.