Coordinated Multi-Cell MU-MIMO Research For The Downlink LTE System

In ordor to satisfy the increasing of data rate requirement by the mobile services and maintain the future competitiveness to other mobile broad band radio access techniques such as WiMAX, LTE which is short for Long Term Evolution and an advanced technique based on more than ten years of Beyond 3G (B3G) system researching, was addressed by the organization of 3GPP at the end of 2004.As the evolution of the 3G mobile communication system, LTE adopted OFDM as a substitute. In order to achieve the fundamental targets for LTE concerned increased data rate, reduced latency, improved system capacity and coverage as well as reduced operator costs, some advanced techniques become a part of LTE like MIMO and link adaptation.Although OFDM and Multiple Input Multiple Output (MIMO) techniques employed can achieve relative high system capacity and provide relative high data rate transmission for the great mass of users,cell-edge users are severely influenced by the intense inter-cell interference (ICI) in multi-cell environment with a frequency reuse factor equal to one, which cause severe degradation of system performance and can impossibly be mitigated by increasing the transmit power of desired signals. Hence, the coordinated multi-cell MIMO technique which can effictively mitigate the inter-cell interference (ICI) was proposed and has been adopted by LTE-advanced as one of the methods to increase cell-edge data rate and system throughput. Therefore, it's meaningful to study and evaluate system performance of LTE based on coordinated multi-cell MIMO technique. The thesis introduces the design method of downlink LTE system level simulation platform and its main modules in details. With the evaluation in system throughput and cell-edge user throughput, this thesis analyses the system characteristics, which will lay a foundation for further researching.