Construction Of Simulation Platform Based On LTE-A With Research And Verification Of MIMO Key Algorithm

As the fourth generation mobile communication technology,LTE-A(Long Term Evolution-Advanced)has made great progress in the uplink and downlink transmission rate and communication quality compared to 3G systems.As a fully promoted communication technology,under the two-way requests of high throughput and reliable communication transmission,digging out more available resources from the space field and providing more stable communication quality from an effective channel feedback perspective has become the key technology of LTE-A.Multiple Users-Multiple Input Multiple Output(MU-MIMO),link adaptation and Hybrid Automatic Repeat reQuest(HARQ)technology and so on provide important technical support in LTE-A protocol.Compared with the traditional point-to-point MIMO technology,MU-MIMO technology based on precoding can provide gaining on multi-users pairing,solve problems of big difference of the number of transmit and receive antennas and antenna correlation and provide higher system capacity;link adaptation technology can adjust the system coding and modulation based on instant change of downstream channel in order to achieve optimal throughput;combining with forward error correction coding technology and automatic request retransmission technology,HARQ provides more rapid and reliable transmission by retransmitting soft merging data based on the error correcting ability.This paper builds a downlink physical shared channel transmission platform based on LTE-A code modulation and other different protocols and achieves MU-MIMO,link adaptation,HARQ and other technologies.The paper completes the simulation verification work of several key MU-MIMO precoding algorithms based on duplex mode of time division and frequency division,including precoding technology based on singular value decomposition and multi-user block diagonalization precoding technology in TDD mode,and MU-MIMO precoding technology based on RANK-2 feedback and RANK-1 MU-MIMO precoding technology based on zero forcing beamforming in FDD mode.The paper loads link adaptation technology and HARQ technology on the basis of these algorithms,and at the same time it simulates the performance and throughput improvement of various MU-MIMO algorithms with loading link adaptation and HARQ.Meanwhile,according to the shortcomings of SINR-based dual-stream MU-MIMO scheduling algorithm,the paper proposes a MU-MIMO scheduling scheme based on modified SINR to increase the throughput of MU-MIMO systems when SNR is high.Finally,this paper puts forward that after joint detection reception with adding the D2 D terminal interaction on MU-MIMO basis,it can simultaneous launch multi-stream MU-MIMO communication to further enhance the throughput of MU-MIMO systems.