Research Of Coordinated Multi-Points Joint Transmission Technology In LTE-A

As the evolution of LTE, LTE-A continues to use MIMO, OFDM and Link Adaptation technologies, and the system structure is not changed. The LTE-A system will have good compatibility with LTE. Now, LTE-A has become the most important candidate standard of the fourth generation mobile communication system, IMT-Advanced. In order to meet the requirement of IMT-Advanced, such as bandwidth, peak rate, user average throughput and frequency efficiency, Carrier Aggregation, Enhanced UL/DL MIMO, Coordinated Multi-Points transmission and reception, Relay, elCIC for Heterogenous Networks and some other key technologies are used in LTE-A system. CoMP technology, in order to solve the problem of ICI(Inter Cell Interference), improves the cell edge throughput. It has become one of the hotspots.The basic idea of CoMP is Coordinated Scheduling/Beamforming(CS/CB) and Joint Processing(JP) between several points. By using this technology, the ICI could be reduced or the interference could be transform into useful signal. So the reception SINR of UE will be improved and the throughput will be increased as well. In the3GPP Rel-9series standards, the definitions and basic principle of CoMP are given. After a period time of research, the primary conclusions of the gain of CoMP have been made. While, in the actual system, there are many problems.In this paper, using the system level simulation platform based on3GPP standards as a major research tool, one of transmission mode of CoMP, JP technology will be researched. The study includes the CoMP UE selection algorithm in CoMP and Single-cell mix mode, and the CoMP cooperating set selection algorithm in semi-dynamic CoMP mode. In the research of CoMP UE selection, the different ratio of CoMP UE impact on the performance of system, especially the cell edge throughput is analysed. The CoMP UE selection algorithms based on the geometry factor and based on the pathloss are in-depth studied. For the semi-dynamic UE Centric mode, the UE will select the cooperating set from several candidate sets. A selection algorithm is studied in this paper, and the analysis is made by the simulation results.