Cognitive Beamforming for Spectral Coexistence of Hybrid Satellite Systems

In Cognitive Radio (CR) communications, an angular dimension can be considered
as an e cient way of exploiting the space dimension in order to enhance
the spectral e ciency of an under-utilized primary spectrum. In this context,
beamforming is an widely considered signal processing solution with the advantages
of spatial discrimination and ltering capabilities. Recently, beamforming
has received important attention for spectrum sharing purpose in the literature
and has been studied for various objectives such as controlling interference, capacity
maximization, Signal to Interference plus Noise Ratio (SINR) balancing
etc. In this chapter, we provide a detailed overview of the existing beamforming
techniques applied in the context of CR networks. Subsequently, we describe
Cognitive Beamforming (CB) techniques which can be applicable in the context
of cognitive Satellite Communications (SatComs).