Cooperation stimulation in cooperative communications: An indirect reciprocity game

The viability of cooperative communications largely depends on the willingness of users to help. However, in future wireless networks where users are rational and pursue different objectives, they will not help relay information for others unless this can improve their own utilities. Therefore, it is very important to study the incentive issues when designing cooperative communication systems. In this paper, we propose a cooperation stimulation scheme for multiuser cooperative communications using indirect reciprocity game. By introducing the notion of reputation and social norm, rational users who care about their future utilities get the incentive to cooperate with others. Different from existing works on reputation based schemes that mainly rely on experimental verifications, we prove theoretically that cooperating with users having good reputation can be sustained as an equilibrium. Moreover, by modeling the action spreading as an evolutionary game, we show through simulations that the equilibria we found are evolutionarily stable and can be reached with proper initial conditions. Finally, simulation results are shown to verify the efficiency and effectiveness of the proposed scheme.