Spectrum Leasing for OFDM-Based Cognitive Radio Networks

In this paper, we propose an Orthogonal Frequency Division Multiplexing (OFDM)-based cooperative communication scheme joint with spectrum leasing. In the proposed scheme, the Primary User (PU) leases some parts of its available resources (in both time and frequency) as a revenue of cooperation to the Secondary Users (SUs) who act as relays for the primary transmission. The optimization of parameters that control the amount of leased resources from the PU to the SU is investigated. An iterative framework is proposed for the PU to find its appropriate relays. Moreover, a dynamic noncooperative game is considered at the relays to compete among themselves for controlling their powers and the Nash Equilibrium (NE) is suggested as the solution of this competition. Analytical results show that the PU achieves a higher data rate by this cooperation process compared with the case where there is no cooperation.