  The theory of wireless information and power transfer in energy constrained
wireless networks has caught the interest of researchers due to its potential
in increasing the lifetime of sensor nodes and mitigate the environment hazards
caused by conventional cell batteries. Similarly, the advancements in areas of
cooperative spectrum sharing protocols has enabled efficient use of frequency
spectrum between a licensed primary user and a secondary user. In this paper,
we consider an energy constrained secondary user which harvests energy from the
primary signal and relays the primary signal in exchange for the spectrum
access. We consider Nakagami-m fading model and propose two key protocols,
namely time-splitting cooperative spectrum sharing (TS-CSS) and power-sharing
cooperative spectrum sharing (PS-CSS), and derive expressions for the outage
probabilities of the primary and secondary user in decode-forward and
amplify-forward relaying modes. From the obtained results, it has been shown
that the secondary user can carry its own transmission without adversely
affecting the performance of the primary user and that PS-CSS protocol
outperforms the TS-PSS protocol in terms of outage probability over a wide
range of Signal to noise ratio(SNRs). The effect of various system parameters
on the outage performance of these protocols have also been studied.
