Coordination of multiple eNBs using short-term channel information

This paper demonstrates if the utilization of short-term channel information, i.e. channel state information (CSI) feedback, is beneficial in the coordination of multiple evolved Node Bs (eNBs) even with the practical non-ideal backhaul. Two CSI feedback delivery schemes, namely user equipment-specific and cell-specific CSI process configuration schemes, are addressed and compared. From the comparison, it is observed that the cell-specific CSI process configuration scheme exhibits acceptable performance with small overheads. Based on the cell-specific CSI process configuration, it is shown that the short-term channel information conveyance through the non-ideal backhaul is factually feasible. In addition, simulation results comparing performance of the inter-eNB coordinated multi point (CoMP) operations with short-term/long-term channel information and only with long-term channel information, verify that the use of the short-term channel information is advantageous. Finally, a signaling model for inter-eNB CoMP using short-term/long-term channel information is illustrated based on the X2 application protocol.