The Research Of Handover That Based On Carrier Aggregation

With the development of mobile communication technology,the third generation mobile communication already cannot satisfy the increasing needs of users.Thus,3GPP(3thGeneration Paetnership Project)is devoted to the 3GPP LTE(Long Term Evolution)as the evolution of 3G(the 3rdGeneration).LTE-Advanced(LTE-A)is the evolution of LTE,its purpose is to meet higher requirement and more applications of the wireless communication market in the next few years,satisfy and exceed the demand of IMT-Advanced(International Mobile Telecimmunication-Advanced),but also keep the LTE well dounward compatible.The carrier aggregation is a key technology in LTE-Advanced.Carrier aggregation technology refers to expanded into component carrier(CC)system by the multiple discrete carrier or the discrete carrier,in order to meet user needs of the bandwidth of the transmission,its main purpose is to increase the bandwidth,improve throughput.Five 20 M transmission bandwidths of CC can implement LTE-Advanced maximum 100 MHz transmission bandwidths by the carrier aggregation.Existing LTE RRC process,such as the RRC connection configuration,and handover process can only support one CC,and the LTE-A UE which support carrier aggregation can work simultaneously on multiple component carrier,what's more the property of diferent cell that the carrier belong to may be different,so the existing process of RRC in the LTE system can't support the carrier aggregation,therefore it need a new process to support the carrier aggregation.First of all,this paper introduces the LTE-Advanced system and carrier aggregation,the technical features of the carrier aggregation was introduced in detail,including the way of carrier aggregation and scene,scheduling of carrier aggregation,carrier aggregation effect on the protocols,etc.For RRC(Radio Resource Control)layer,it increases the Secondary Cell(SCell)and its related configuration,so it is necessary to increase at the RRC layer process of Secondary Cell,which includes the handover process of carrier aggregation.Secondly introduces the LTE system handover process,it can be divided into two types: handover intra eNB and handover inter Enb.This paper describes the control of the handover in the RRC layer with two processes.And analyzed the LTE handover failure handling process in the system.And then according to the analysis on the performance of carrier aggregation and the handover process of LTE system,handover based on carrier aggregation process is studied in detail.Carrier.this paper divided the handover based on carrier aggregation into SCell changes only and the Primary Cell(PCell)only two cases,analysis this two cases and give the processing of every case.At last it introduces the processing of various kinds of handover failure.Finally,through the actual environment on the above theory is verified and gives the test results,it can be seen from the test results,the existing handover scheme support with the function of carrier aggregation,and can keep the rate after handover,so ensures the dounward compatible with LTE standard,handover control signaling all included in the RRC signaling,will not bring additional signaling overhead for the system.