Collaborative Spectrum Sensing with a Stranger: Trust, or Not to Trust?

The game of collaborative spectrum sensing is discussed for cognitive radio systems, in which an honest secondary user collaborates with an unclassified secondary user. The honest secondary user needs to determine its trustiness to the collaborator while the collaborator, if being malicious, needs to find the optimal tradeoff between causing more damage to the honest secondary user and hiding its own type. The theory of signaling game is applied to find the equilibrium of the game. Numerical results are provided to illustrate the equilibrium strategies of both secondary users. An interesting observation is that the attacker is unable to attack in the Bayesian equilibrium in certain situations.