Research On Channel State Information Measurement Based On CSI-RS

In order to provide high-speed service transmission and guarantee the quality of user experience,the MIMO technology is introduced as well as the spatial multiplexing transmission mode in the LTE-A system.And for adjusting the downlink transmission parameters dynamically the eNodB need obtain the Channel State Information(CSI),termed as Rank Indicator(RI),Precoding Matrix Indicator(PMI)and Channel Quality Indicator(CQI).However,in the current commercial mobile communication system,the UE feedback method for CSI acquisition is used commonly,which makes the technology of terminal CSI mesurement have a very strong application research value for a long time in the future.The terminal CSI measurement based on CSI-RS(Channel State Information Reference Signal)is studied in this thesis.Firstly,several classical measurement algorithms of RI,PMI and CQI are analyzed from the aspects of throughput and complexity.It is concluded that the RI value measured by Max-MMSE-PostCP(Max MMSE Post Channel Capacity)algorithm is more accurate,the SVD algorithm measuring PMI both reduces the complexity and ensures the system throughput,and Exponential Effective SNR Mapping(EESM)algorithm of CQI mesurement has low complexity although it makes a little error.Then,based on the resource mapping characteristics of CSI-RS,two broadband CQI measurement criterions and a lowcomplexity RI/PMI joint measurement criterion combined with Max-MMSE-PostCP algorithm and SVD algorithm are proposed,and their accuracy are analyzed in fastfading channel and blockfading channel.Finally,the practical feasibility of the RI/PMI joint measurement criterion and the CQI measurement criterion is verified in the periodic broadband reporting scenario of the TM9(Transmission Mode 9).The simulation results show that the CSI measurement criterion based on the CSI-RS proposed in this thesis reduces the measurement complexity,and also makes the system throughput grow stably in fastfading channel and blockfading channel.In addition,the simulation results in TM9 demonstrate the accuracy and the application value of the CSI measurement criterion.