Spectrum leasing via selective cooperation in distributed cognitive radio networks

Cognitive radio (CR) has been widely recognized as a promising paradigm to achieve efficient use of the spectrum resource. While a lot of attention has been paid to the hierarchical access model of CR, the spectrum leasing model in which PUs can actively lease their spectrum to SUs for certain reward has not been studied thoroughly. In this paper, by assuming a PU is willing to lease its bandwidth for a fraction of time to SUs in exchange for selective cooperation, we propose a game model to describe the dynamic interaction between the PU and SUs. In our model, the PU plays a game with each of the potential SUs and selects the best one to cooperate with. We prove that there is always a unique Nash Equilibrium (NE) for each game. Moreover, we propose a simple distributed algorithm for practical implementation of the model. Simulation results verify that our approach can benefit both the PU and the SU in terms of utility and transmission rate.