Research On CoMP And Clusering In LTE-A Downlink System

Recently, mobile terminals such as smart phones, tablets play an indispensable role in people’s work and life, which require better performance of wireless mobile communication service. LTE-Advanced was proposed as a new generation of mobile communication network, in order to meet the International Telecommunication Union-Radio communication sector’s requirements for the international mobile communication. LTE-Advanced employed plenty of new technologies, such as carrier aggregation, Advanced MIMO, coordinated multipoint transmission, relay and so on. For growing demands for mobile communication, communication networks are becoming more intensive, which results in severe inter-cell interference. Thus, coordinated multipoint communication has raised attentions because of its ability to increase the throughput of users in cell edge and the spectrum efficiency.When applying coordinated multipoint communication technology,what needed to do first is to determine base stations’ cooperators. Different cooperators in different time will gain different performance. Thus, how to select partners and adopting which approach to collaborate are the key points in coordinated multipoint communication. In this paper, clustering strategy in coordinated multipoint communication and cooperation ways were studied, and the former’s performance was analyzed in detail. The main research results obtained were as follows:1. LTE-A system and coordinated multipoint communication were studied. The function of Co MP based on the LTE system level simulation platform was designed and realized, which consists of judging users at cell edge, clustering and resource allocation. The platform was provided by Vienna University of Technical. The new functions added were modular-designed, which maintained compatibility with the original platform and was convenient for other researchers’ further study. When distinguishing users at cell edge, a method called SINR threshold was used. All the resource blocks were divided into two parts, one for cooperation users, and the other for central users. The ratio of the two parts depends on the ratio of cooperation users and central users. Meanwhile, different procession methods were assigned to these two kinds of users.2. Clustering methods were studied. A hybrid clustering strategy based on time detection was proposed. The proposed method merged the typical dynamic clustering and static clustering, absorbing their advantages and avoiding their disadvantages. Meanwhile, the functions of these three clustering methods mentioned above were designed and realized on the LTE simulation platform. The simulation results showed that the performance of Co MP was better than Non-Co MP, the proposed method was superior to static clustering and close to dynamic clustering, while simulation running time was shorter than dynamic clustering, which means less computation.