The Research Of Grouping Algorithm For Collaborative MIMO Based On UE-Centric Scheme

As a key technology of LTE-Advanced, Collaborative MIMO (Coordinated Multiple Point, CoMP) could prominently enhance performance of UEs located on cell-edge, which has been paid great attention to and deeply researched, and would play an important role in 4G. The key point of C-MIMO is to construct collaboration of neighbour cells, or construct a collaborative area (CA), and inter-communicate information between base stations, to realize joint transmission in uplink, or precoding in downlink, for interference cancelled of UEs.One important problem for C-MIMO is to determine collaborative areas. Current researches on downlink CoMP are mostly based on cell-centric scheme, which means certain fixed cells are grouped together to form a CA, and UEs dropped in the area of these cells are served by in CoMP mode. In other words, CAs are determined by the network and independent with UE distribution. Cell-centric CA is more convenient in terms of implementation, but obviously it is not the optimal way, and the performance gain is not so attractive.Theoretical research and simulated practice in this thesis lead to a new grouping algorithm called SHO (Soft Handover) based on UE-centric, which sorts received signals of each UE from strongest to weakest; if certain UEs have same strongest sectors, they should be put into same UE group, and these sectors form the CA of this group. SHO grouping algorithm could afford more freedom for UE and sector grouping, increase efficiency of collaborative transmission, and achieve great performance gain. A simple downlink CoMP model has been made up with SHO scheme (CoMP-SHO), and from simulation results we have known it could provide good system performance gain, which would have wide development in future.