Resource allocation in relay-assisted MIMO MAC systems with statistical CSI

In this work, the issue of non-cooperative resource allocation in the uplink of a relay-assisted MIMO MAC (multiple input multiple output multiple access channel) system with statistical CSI (channel state information) is considered. The mobile transmitters pursue individual achievable ergodic rate maximization, whereas the relay aims at optimizing the global performance of the system. The problem is formulated as a Stackelberg game with the relay as the leader, and the multiple access users as the followers. Moreover, necessary and sufficient conditions for beamforming optimality at the relay are derived, which simplifies the resource allocation process. Finally, numerical results corroborate the theoretical findings.