Radio enabling techniques for IMT-advanced (4G) and beyond: WINNER+ project

Enabling radio innovation techniques for IMT-Advanced and beyond investigated in the WINNER+ project are summarized in this paper. These techniques survey five innovation areas: Advanced Antenna Systems (AAS), Advanced Radio Resource Management (ARRM), Network Coding, Coordinated Multipoint (CoMP) transmissions and Spectrum Technologies. In AAS, under the framework of cellular multiuser MIMO systems, the proposals focus on how to make the channel state information (CSI) available at the transmitter, to reduce the pilot overhead and to utilize the acquired CSI for efficient downlink precoding. Within CoMP transmissions, coordinated scheduling and/or beamforming and joint processing are briefly presented and analysed. In ARRM carrier aggregation is described. In network coding the application of non-binary codes is presented. Concerning spectrum technologies special attention is given to the co-existence of macro-layer and femto-layer and consequently how to coordinate the interference.