Cognitive Hybrid Satellite-Terrestrial Relay Networks with Simultaneous Energy and Information Transmission

In this paper, a cognitive hybrid satellite-terrestrial relay network with power splitting-based energy harvesting (EH) has been proposed. Herein, a primary satellite source coexists with a secondary transmitter-receiver pair on the ground and communicates with its terrestrial user by exploiting both direct and relay links. It is further assumed that secondary transmitter has the radio-frequency-based EH capability and harvests energy from the primary satellite's signal. Hereby, it explores an opportunity for spectrum access through an amplify-and-forward based relay cooperation with the primary satellite network. We analyze the performance of the primary satellite network and secondary terrestrial network by adopting Shadowed-Rician fading for satellite links and Nakagami-m fading for terrestrial links by deriving their corresponding outage probability expressions. In addition, to get useful insights, expressions for throughput and energy efficiency of primary satellite network are provided assuming a delay-limited scenario. Moreover, our results elucidate the impact of power splitting factor and spectrum sharing factor on the system performance.