Research On Downlink CoMP Technology In LTE-Advanced System

With the Long Term Evolution Technology (LTE) getting to be mature, and also tomeet the technology needs of International Telecommunication Union for thefourth-generation communication technologies, the Third Generation PartnershipProject (3GPP) organization developed the researching goal of LTE-Advanced which isthe evolution version of LTE. At the same time, we introduced a number of keytechnologies to meet the needs of the users in rates and spectral efficiency，those keytechnologies contain Coordinated multi-point transmission and reception (CoMP)technology.As one of key technologies in LTE-Advanced, CoMP technology can effectivelyreduce or eliminate the interferences between the neighboring cells throughcollaboration among many transmission points by the ways of the joint transmission ofuser data, coordinated scheduling or beamforming method, it can enhance the signal tointerference plus noise ratio of user received signal, therefore improve cell edgecoverage, the spectral efficiency of the cell edge and system spectral efficiency areincreased.CoMP technology can be divided into downlink coordinated multi-pointtransmission and uplink coordinated multi-point reception, the downlink Coordinatedmulti-point transmission technology was studied by this paper. This paper firstly studiedthe basic classification, transmission scheme, the frequency division scheme ofcoordinated multi-point transmission and so on. And then mainly studied JP-SU-MIMOtransmission scheme model based on SU-MIMO, analyzed the model of this scheme,studied the key contents containing cooperating user definition methods, cooperating setpartition and user scheduling algorithms, and proposed the dynamic cooperating setpartition algorithm based on a specific scenario. Mostly the current commonly usedmode of operation is the fixed cooperating set partition method in the performancesimulation of CoMP, although this method is simple in terms of implementation, but itdoesn’t consider the overall performance of the system, so the system throughput gainwhich is obtained by this method is limited. The dynamic cooperating set partitionmethod proposed by this paper, which was based on the system capacity, can effectively improve the system performance in the case of limited complexity. At the end, wesimulated both JP-SU-MIMO transmission scheme and cooperating set partitionalgorithms proposed by the paper. From the results of the simulation, we can get theconclusion that JP-SU-MIMO transmission scheme can effectively improve spectralefficiency of the cell edge users and spectral efficiency of system, but cooperating setpartition algorithms proposed by the paper can further improve the performance ofJP-SU-MIMO transmission scheme.