A Robust Stackelberg Game Approach for Joint Relay Selection and Optimal Power Allocation for Cooperative Device-to-Device Communication Under Channel Uncertainties

Device-to-device (D2D) communication enables direct communication among users in close proximity, bypassing the core network. With relay assistance, D2D users can have the leverage of transmitting data directly over long distances with increased throughput. However, due to dynamic nature of wireless networks, there may be uncertainty in the channel parameters known to a user. In this paper, the authors address the joint problem of relay selection and optimal power allocation in single-source multi-relay D2D networks when the perfect channel state information for relay channels is unknown. The uncertainty has been modeled as a bounded difference between actual and nominal values. An incentive-based robust Stackelberg game is proposed in which the relay devices determine the price of power allocated to them by the source device. A closed form expression for the optimal power was obtained. Further, the Stackelberg equilibrium was derived and its existence and uniqueness was demonstrated. The performance of the proposed game with the nominal game was compared. Simulation results confirm the effectiveness of the robust game-theoretic solution in an incomplete information environment.