Overlay cognitive radio networks: A distributed matching scheme for user pairing

In this paper, an overlay cognitive radio network is considered where each primary user leases access time to selected secondary users in exchange for their cooperation. To optimize the network performance in a distributed way and being inspired by matching theory, we model the cognitive radio network as a matching market and we deal with the pairing problem among the primary and the secondary users as a many-to-one matching problem with externalities. A modified scheme based on the well-known deferred acceptance mechanism is proposed, leading to a stable matching. The performance of the proposed scheme is evaluated and compared to the performance of a centralized scheme that results in optimal performance for the primary users and a simple pairing scheme that is based on the distance among the users. As is highlighted in the numerical analysis, the proposed mechanism leads to similar performance with the centralized scheme in terms of primary users´ utility whereas, it outperforms the other two schemes from the perspective of secondary users.