Intercell Interference Mitigation with Multicell Beamforming and Relays

In multicell systems users with low signal to interference plus noise ratio (SINR) are mostly close to the cell edge, since they are subject to interference from adjacent cells and suffer from higher attenuation in the serving cell. With beamforming and scheduling, an improved fairness among the users can be achieved and especially cell edge users profit from this technique.

If users are strongly shadowed even beamforming cannot improve their SINRs or only at the expense of a strongly reduced sum rate of all scheduled users. In this case, relay stations close to the shadowed users should achieve an additional gain. Therefore, in this project a system configuration using multiple antenna techniques at the BS and relays (with focus on Type 2) in a multiuser multicell scenario is considered.

Within this project new methods to reduce intercell interference are investigated. These methods are based on suitable combinations of relaying and beamforming. These investigations start from the baseline system for Rel-8 and Rel-9 and cover new interference mitigation schemes for 3GPP LTE-Advanced Rel-10 and beyond. The unicast transmission is considered with full frequency reuse in the network. The system allows multi-base stations (BSs) cooperation by a central unit to reduce the intercell interference.