Coalition formation games for cooperative spectrum sensing in cognitive radio networks

Abstract

Cooperative spectrum sensing is an effective technique to enhance the sensing performance and improve the spectrum efficiency in cognitive radio networks (CRNs). This chapter considers a CRN with multiple primary users (PUs) and multiple secondary users (SUs) and presents two cooperative spectrum sensing and access (CSSA) schemes. The first CSSA scheme allows each SU to sense one channel and is formulated as a hedonic coalition formation game, where each coalition is composed of the SUs that sense on the same channel. The value function of each coalition and the utility function take into account both the sensing accuracy and the energy consumption. The algorithms for decision node selection in each coalition and SU decision-making are proposed to obtain a final network partition, which is proved to be both Nash stable and individually stable. This chapter then focuses on a more general scenario, where each SU can simultaneously sense multiple channels based on its traffic demand. The traffic demand-based CSSA scheme is formulated as a nontransferable utility (NTU) overlapping coalitional game, where each SU implements a cooperation strategy based on its expected payoff. Two algorithms, namely overlapping coalition formation (OCF) and sequential coalition formation (SCF), are proposed to obtain a coalition structure. The OCF algorithm guarantees the stability of the coalition structure, while the SCF algorithm reduces the computational complexity and information exchange. Simulation results show that the proposed algorithms significantly enhance the network throughput.