Cooperative cognitive radio networking for opportunistic channel access

In this paper, an opportunistic channel access for cognitive radio networks (CRNs) with multiple channels is proposed, whereby the secondary users (SUs) cooperate with primary users (PUs) to improve the latter´s throughput and gain transmission opportunities in return. Cooperation on single channel is studied first, which is modeled by the Stackelberg game. By analyzing the game, the access time allocation of the PU and the optimal transmission power of the SU can be obtained. Then, based on the outcome of the above game, cooperation on multiple channels in the network is studied. To better exploit transmission opportunities on different channels, a cluster-based cooperation scheme (CBC) is proposed, whereby SUs first form a cluster, select best SUs to obtain the maximum sum of the access time using maximum weight matching, and then share the obtained channels fairly using congestion game and quadrature signalling. The condition for Nash Equilibrium (NE) of the congestion game is provided and an algorithm for CBC scheme is proposed. Numerical results demonstrate that, with the proposed scheme, the SUs can get more average access time and achieve higher fairness, compared with the random channel access approach.