Two-Tier Spectrum Trading Strategy for Heterogeneous Cognitive Radio Networks

The heterogeneous network structure is a promising paradigm to improve the quality of service across the entire network. Nevertheless, such structure is challenging due to the presence of multiple-tier secondary users (SUs). In this paper, we investigate the effect of spectrum allocation in a heterogeneous cognitive radio networks with a primary network and two-tier secondary networks, and propose a two-tier spectrum trading strategy which includes two trading processes. In Process One, we model the spectrum trading as a monopoly market, where the spectrum owner (PO) acts as the monopolist and the first-tier secondary users (FSUs) act as the buyers. We design an optimal quality-price contract with the objective of maximizing the utility of PO, and the FSUs will choose the spectrum with appropriate quality and price in order to enhance their satisfaction. In Process Two, the spectrum trading is modeled as a multi-seller, multi-buyer market. The dynamic behavior of second-tier secondary users (SSUs) is studied using evolution game, while the competition among FSUs is analyzed via noncooperative game where the Nash equilibrium is considered as the solution. The existences of the optimal contract and Nash equilibrium are demonstrated in the performance evaluation.