简介:文章提出了先用CDMA/LTE双模基站成片地替换原CDMA网络基站,再将原CDMA网络设备用于新建扩容的移动网络扩建方案,并从一次性建设成本、运营成本、维护费用等角度加以分析论证。
简介:Two-dimensional(2D)multiple-inputmultiple-output(MIMO)iscurrentlyconcentratedonpropagationinhorizontalplane,buttheimpactofelevationangleisnotconsidered.However,duetothethree-dimensional(3D)characteroftherealMIMOchannel,2DMIMOcannotachievetheoptimalsystemthroughput.Amultiple-userMIMO(MU-MIMO)userpairingschemewasproposed,inwhichtheverticaldimensionwastakenintoconsideration.Intheproposedscheme,a3DcodebookbasedonfulldimensionMIMOchannelwasdesigned;thentwo3DMU-MIMOuser'spairingschemesareproposedcombiningtheproposedjointandseparate3Dcodebook.Simulationevaluatestheproposed3Dcodebookaideduserpairingschemeandcompareswiththeprevious2DMU-MIMOuserpairingtechnology.Owingtotheadditionalspatialdegreeoffreedominverticaldimension,theproposed3DMU-MIMOuserpairingschemescaneffectivelyimprovetheoverallsystemperformance.