Overview of spectrum sensing technologies for satellite and space communications based on cognitive radio networks

Abstract

The limited available spectrum of satellite and space communications result in new techniques to reuse the free spectrum. Cognitive Radio (CR) is one of the most promising techniques for such reusing processes. Spectrum sensing (SS) is the core process of cognitive radio which is used to sense the available temporary free bands, holes, of the sensed spectrum.  Many technologies are proposed to achieve both narrow-band and wide-band spectrum sensing. Three paradigms of spectrum sensing applications such as the interweaving approach, the underlay approach and the overlay approach are explained. Many scenarios are proposed to utilize cognitive radio architecture at both standalone and cooperative approaches in satellite communications. The proposed scenario is based on cooperative Sub-Nyquist wideband sensing basis. Nano-computing process is highly required to achieve real-time communication for spectrum sensing in cognitive radio due to the intensive required computations. The Simulation of the proposed scenario showed that it efficiently saves frequency resources, overcomes spectrum underutilization problem, noise and interference problems with an accurate reconstruction.