Cooperative spectrum sharing in cognitive radio networks with proactive primary system

In this paper we investigate the cooperative spectrum sharing in cognitive radio networks with proactive primary system. In our scheme, Primary User (PU) is rewarded for sharing its licensed spectrum with Secondary Users (SUs) by charging their total throughput directly. The PU performs as the leader and chooses its interference-cap and transmit-power jointly to maximize its reward from spectrum-sharing with SUs. Meanwhile, the SUs perform as the followers and adapt their transmit-power according to the PU´s decisions to maximize their net-utilities. We first explore the intrinsic property of this PU-SUs sharing problem and then utilize an efficient Simulated Annealing algorithm for the optimal solution. Our numerical results show that both the PU and the SUs gain from this spectrum-sharing cooperation and thus achieve a win-win situation. In addition, as its own transmission requirement increases, the PU limits the sharing of its channels gradually to maintain its own target quality of service. Correspondingly, both the net-profit of PU and the net-utility value of SUs decrease¹.