Uplink CoMP and the Applications in TD-LTE Networks: Principles and the Field Trial

TD-LTE uses the same frequency in the whole network, thus the inter-cell interference severely damages the cell-edge user throughput and the network capacity is therefore suffered. Uplink Coordinated Multi-Point (CoMP) has the potential to improve uplink capacity and reduce inter-cell interference by jointly processing the received signals from more antennas of the adjacent nodes, which is one of the key technologies of LTE Advanced system. Uplink CoMP is implemented at the eNodeB side with no requirement on terminals or protocols and thus is easy be introduced in the current network. This paper introduces LTE uplink CoMP principles, use cases and recent field trial results in the TD-LTE networks. The field trial results showed that when there is no interference, uplink CoMP gain at the cell border is 20 similar to 40%, the lower working point, the larger improvement. When there is interference, uplink CoMP gain at the cell border is 50 similar to 100%. The cell-edge user experience thus can be significantly improved.