부산대학교 도서관

Cognitive Radio applications in satellite communications become challenging and promising research owing to limitations over the available spectrum. Broadband satellite services continuously call for extra band resources, especially in Ka-band. The coexistence among multiple systems including two satellites systems and terrestrial networks sharing the band (17.7–18.1 GHz) is proposed. Harmful interference analysis and detection are provided based on Energy Detection and Matched Filter using an independent dipole chain at cognitive receiver. Also, spectrum sharing decision is deduced through simulation and analytical results. Then exploitation of 3D LCMV (Linearly Constrained Minimum Variance) is adapted for coexistence enabling between systems and protecting cognitive receivers. Spatial filtering is designed based on Focal Plane Array Reflector (FPAR). Finally, simulation and analytical results are used to provide a comparative performance evaluation of spectrum sensing techniques. Real link parameters and measurements from Nilesat (The Egyptian Satellite Company) are considered in calculations. In addition, 3D Beamforming performance evaluation is provided through simulation.