  In communication systems where users share common resources, users' selfish
behavior usually results in suboptimal resource utilization. There have been
extensive works that model communication systems with selfish users as one-shot
games and propose incentive schemes to achieve Pareto optimal action profiles
as non-cooperative equilibria. However, in many communication systems, due to
strong negative externalities among users, the sets of feasible payoffs in
one-shot games are nonconvex. Thus, it is possible to expand the set of
feasible payoffs by having users choose convex combinations of different
payoffs. In this paper, we propose a repeated game model generalized by
intervention. First, we use repeated games to convexify the set of feasible
payoffs in one-shot games. Second, we combine conventional repeated games with
intervention, originally proposed for one-shot games, to achieve a larger set
of equilibrium payoffs and loosen requirements for users' patience to achieve
it. We study the problem of maximizing a welfare function defined on users'
equilibrium payoffs, subject to minimum payoff guarantees. Given the optimal
equilibrium payoff, we derive the minimum intervention capability required and
design corresponding equilibrium strategies. The proposed generalized repeated
game model applies to various communication systems, such as power control and
flow control.
