A Game-Theoretic Analysis of Decode-and-Forward Cooperation in Gaussian Channels

A game-theoretic analysis of decode-and-forward user cooperation is presented. Cooperative communications is modeled as a game in which the two participating terminals are selfish and seek to maximize their own payoff, a general utility function that monotonically increases with signal-to-noise ratio. The terminals communicate to a common destination terminal using orthogonal additive white Gaussian noise (AWGN) channels. Both deterministic and mixed-strategy Nash Equilibria are studied. Results show the selfish nature drives users away from a mutually cooperative equilibrium in a one-shot game. However, when the communication scenario is modeled as a repeated game, a Nash Equilibrium in which users cooperate can be achieved. The requirement for such an equilibrium is that users value future payoff and a proper power control scheme is utilized. Examinations of two possible payoffs (i.e., channel capacity and transmission reliability) show that such a power control scheme can be easily implemented.