Users Selection Researh In CSB

The LTE-Advanced has been identified as one of the two major4G technology byITU. In order to meet the higher spectral peak efficiency,3GPP organization has putforward a number of new key technologies, there the Cooperative Multi-pointtransmission/reception technology is mainly used to improve the performance of the celledge users.According to whether to share data between base stations, Cooperative Multi-pointtransmission/reception is divided into two broad categories, including Joint Processingand Coordinated Scheduling/Coordinated Beamforming. In Joint Processing, all basestations in the coordinated set transmit data to service-user, converting interferencechannel into effective channel. Although user can achieve good performance throughJoint Processing, there will caused heaviest load in uplink and X2interface as user mustfeedback the channel statement information to base station and base stations exchanginguser data information in the process of Joint Processing. In CSB, bases stations don’tshare users’ data information, but only share users’ CSI. Base stations doing simplescheduling and beamforming to improve edge users’ throughput rate. Lower X2loadand lower equipment cost make easier to achieve in practical system.In this thesis, we mainly study the method of users’ selection in CSB. To improveperformance of edge users and the average throughput of the cell through a simple userpairing respectively in the system of explicit feedback and code word selection. Thesisand arrangement are as follows: First, an overview of the research background anddevelopment in the world of CoMP; Then details the basic element of CoMP, includingconcept, concepts, classifications, feedback scheme and so on. Next, a simple userpairing and selecting beamforming scheme is presented with explicit feedback. Pairededge users with center users, and select the appropriate beamforming. The performanceof cell edge users are improved by sacrificing some performance of center users. Thesimulating result show that this simple user pairing can improve the performance ofedge users and middle users and the average throughput rate of system obviouslycompared with present algorithm. Meantime, taking into account the limited uplink feedback, then an improved user selection method is presented with codebook systembased on the theory of improving the performance of edge users by sacrificing theperformance of center users. The simulating results show that this algorithm canobviously improve both the performance of edge users and the average throughput rateof system.