Research On The Method Of Downlink Multi-streams Beamforming In The TD-LTE System

This paper analyzes and studies the related technology in TD-LTE system ofbeamforming and gives the corresponding simulation results at last.Firstly, the paper brings a brief idea of the key technologies for Physical Layer inTD-LTE System, such as the radio frame structure, all the physical channels and physicalsigns of the Physical Layer and the OFDM technology. Secondly, this thesis introduces thekey technologies of PDSCH, because the technologies of beamforming are based onPDSCH. In the key technologies of PDSCH, we focus on three schemes of MIMO. Theyare transmited diversity, spatial multiplexing and beamforming respectively.In the fourth chapter, the paper emphasizes the related technologies of the process ofthe beamforming from the aspects of SU-MIMO beamforming and MU-MIMObeamforming, which includes the algorithm of calculating beamforming weight vectoralgorithm on the eNodeB side and the algorithm of correlation detection on the UE side.With the acquisition method of the beamforming weight vector on the side of the basestation, we focus on the existed program of SU-MIMO beamforming, and propose aimproved beamforming weight vector approach for the shortcomings of the existedprogram.Correlated the detection algorithm on the UE side, we analyze the channel estimationalgorithm. In the beamforming scheme with DM-RS as the case of the pilot signaltransmission, we discuss that how to get the pilot channel coefficients and how to get thechannel coefficients of the entire band direction through various interpolation algorithms.In the derivation of frequency domain interpolation algorithms, against of thecharacteristics of the distribution of the downlink DM-RS is not equally spaced oncontinuous PRBs, we improve the DFT transform domain interpolation algorithm. Andanalysis of the simulation results of the improved algorithm is given in the fifth chapter.