Cooperative Communication-Aware Spectrum Leasing in Cognitive Radio Networks

Abstract

In this paper, we focus on the dynamic spectrum access of two infrastructure-based cognitive radio networks, primary network and secondary network, which are collocated with each other. To improve network performance of two networks, we propose a cooperative communication-aware spectrum leasing framework, in which, primary network leverages secondary users as cooperative relays, and decides the optimal strategy on the relay selection and the price for spectrum leasing. Based on primary network's strategy, secondary network determines the length of spectrum access time it purchases from the primary network. Finally, each network allocates the total spectrum access time of the network among its end users. The above sequential decision procedure is formulated as a Stackelberg game, with primary network acting as the leader and secondary network as the follower, and a unique Nash Equilibrium (NE) point is achieved through backward induction analysis. At this NE point, both networks maximize their utilities in terms of transmission rate and revenue/payment. Meanwhile, the optimal relay selection and spectrum resource allocation among all the users are also derived based on the Nash Equilibrium. Simulation results show that both primary and secondary networks achieve higher utility by exploiting cooperative transmission under our proposed framework, which gives both networks incentive for cooperation.