Multiuser diversity of spectrum leasing in cognitive radio networks

In this paper, an adaptive spectrum leasing scheme is proposed for multiuser cognitive radio networks and multiuser diversity is analyzed. Based on two-path successive relay and decode-and-forward relay protocols, each cognitive user intelligently switches the spectrum leasing protocols to help the primary data transmission. As a reward, the spectrum is then leased to the cognitive user for secondary data transmission. The best cognitive user that achieves the largest secondary rate while satisfying the primary rate target is selected in the spectrum leasing. The multiuser diversity of the spectrum leasing scheme is analyzed and the throughout is shown to be proportional to log log m for large number of m cognitive users.