Cooperative Spectrum Allocation for Cognitive Radio Network: An Evolutionary Approach
Cooperative sharing of spectrum among one Primary User (PU) and multiple Secondary Users (SUs) helps to enhance the throughput of the whole system. In this paper, the authors propose a two-tier game in which SUs make their decisions on whether to cooperate under replicator dynamics and the PU adjusts its strategy to allocate time sub-slots for the cooperative SUs' transmission. Furthermore, they develop the distributed algorithm to describe the learning process of SUs, and prove that the dynamics can converge to the Evolutionary Stable Strategy (ESS) efficiently, which takes both transmission rate and fairness into consideration. Simulation results show that the proposed mechanism converges to ESS automatically, at which point all the SUs will keep their strategies.