The Spectrum Sharing in Cognitive Radio Networks Based on Competitive Price Game

The competitive price game model is used to analyze the spectrum sharing in the cognitive radio networks. This paper focuses on the improved spectrum sharing problem with constraints of available spectrum resource from primary users. The constrained spectrum sharing model based on competitive price game is established. In order to achieve the spectrum sharing strategy that satisfies the constraints from primary users, the Rockafeller multiplier method is applied to deal with the constraints of available licensed spectrum resource, and the improved profit function is achieved, which can be used to measure the impact of shared spectrum price strategies on the system profit. However, in the competitive price game based spectrum sharing problem of practical cognitive radio network, primary users have to determine the shared spectrum price without the acknowledgement of the other primary user’s price strategies simultaneously. Thus a fast gradient iterative calculation method of equilibrium price is proposed, only with acknowledgement of the shared spectrum price strategies during last cycle. Through the adaptive iteration at the direction with largest gradient of improved profit function, the equilibrium price strategies can be achieved rapidly. It can also avoid the predefinition of the adjustment factor according to the parameters of communication system in conventional linear iteration method. Simulation results show that the proposed competitive price game based spectrum sharing model can be applied in the cognitive radio networks with constraints of available licensed spectrum resource, and it has better convergence performance.