A Coordinated Multiuser Relaying Technique through Interference Precoding at the Base Station

We propose a new precoder design technique for a cooperative base station (BS) and relay station (RS) network. The proposed approach provides substantial reduction in terms of transmission power for a given set of target user rates as compared to a scheme known in the literature. The system model considered is a BS serving a number of users directly and another set of users through a multiple-input-multiple-output (MIMO) wireless RS. A set of beamformers are designed at the RS and the BS to achieve a set of target rates for users. Compared to the existing scheme, we make use of the knowledge available at the BS in terms of the information transmitted by the RS to perform more efficient interference mitigation which results into a lower overall network power consumption. Simulation results demonstrate the advantage of the proposed technique.