A Contract Theory Approach-Based Scheme to Encourage Secondary Users for Cooperative Sensing in Cognitive Radio Networks

In cognitive radio networks, the identification of a primary user (PU) with the help of spectrum sensing is very important for a secondary user (SU), such that interference free transmission can be performed. In recent times, the cooperative spectrum sensing that improves the reliability of the decisions made about the presence of a PU and overcoming hidden terminal problem by obtaining sensing results from different sensors is gaining much attention. However, the selfish SUs are sometimes not willing to cooperate. This paper proposes a contract theory-based approach, which is an incentive design mechanism where the participants are offered appropriately designed reward to encourage cooperation. The secondary base-station (BS)-SU interaction is modeled as a labor market using contract theory. Contract theory helps in analyzing the case of incomplete information where the BS is not aware of the SU's private information. Further, the contract is formed in such a way that only the limited number of noncorrelated SUs can participate in sensing such that unnecessary energy consumption is reduced. Simulation results show that the contract can effectively incentivize SU's cooperation, and outperforms the considered benchmark scheme in terms of PU detection probability.