Partner selection in cooperative networks: Efficiency vs fairness in Ricean fading channels

Enabling collaboration among users to relay messages for others is crucial to efficiently assign network resources and maximize network goodput. However, in some cases subsets of users would prefer a selfish behavior (by refusing cooperation) to protect their own performance. Depending on the application and on the particular propagation environment, an efficient grouping algorithm that assigns partners at MAC layer should conveniently address the problem of maximizing the network goodput without penalizing the performances of single users. This can be done by including specific constraints (user-fairness) that pose limitations on the amount of resources, e.g. energy, that might be reserved for relaying information of partners. In this paper the partner selection algorithms are designed to maximize the network lifetime while guaranteeing user-fair assignments. We analyze the network lifetime gain that can be achieved in a realistic network where fading significantly differs from Rayleigh and propose a novel low-complexity partner selection algorithm that maximizes the energy efficiency of the network while guaranteeing the given fairness constraint for each user.