Opportunistic TPSR cooperative spectrum sharing protocol with secondary user selection for 5G wireless network

In this paper, we consider a cognitive radio system, where multiple secondary users coexist with one primary user. To improve the transmission efficiency of the system, we propose a cooperative spectrum sharing protocol with secondary user selection by using decode-and-forward and two-path successive relaying techniques. Furthermore, we derive the close-form of outage probability of the primary system. The upper bound of outage probability of the secondary system is also derived. In addition, the theoretical results are verified via numerical simulations. Numerical results show that the primary outage performance is much better than conventional selective relaying schemes. In the low secondary Signal-to-Noise Ratio region, the secondary outage performance is also better than conventional selective relaying schemes.