Research On Millimeter Wave Transmission Technology Based On Beam Communication

Beam-based communication and millimeter wave transmission are the key technologies of NR.Millimeter wave communication has serious path loss problems,and the use of large antenna arrays and beam alignment technologies can help improve link quality.This paper studies the antenna array configuration,beam selection,and beam training for millimeter wave transmission.The main research contents are as follows:(1)Research on the average reach and rate of a system based on a uniform planar antenna array.The antenna structure of Uniform Rectangular Planar Array(URPA)is studied,and its direction vector characteristics are analyzed.According to the horizontal and vertical two-dimensional direction models,the expressions of the average reachability and velocity of the system are given.Studies have shown that using planar antenna arrays can achieve better spatial division than linear arrays,and the antenna takes up less space.(2)Research on beam selection algorithm based on QR decomposition.Based on the scenario of digital domain and link domain precoding,where the number of links is less than the number of antenna elements,a beam selection method is proposed.This method divides users into two groups: Noninterference-Users(NIUs)and InterferenceUsers(IUs).For the NIUs group,the beam corresponding to the highest received power is selected.For the IUS group,QR decomposition and iteration The method seeks the beam combination that maximizes the system and rate,and then diagonalizes the matrix formed by the beam combination of the NIUs group and the IUs group to eliminate interference between users.Comparing the performance of the proposed algorithm with the maximum amplitude algorithm,interference perception algorithm and ZF method,the spectrum efficiency and power efficiency are improved.(3)Research on beam training scheme of single RF chain in MU-MIMO.Two beam training schemes based on single RF chain are proposed: Sequential DownlinkUplink(SDU)sector scanning scheme and Sequential Downlink-Downlink(SDD)Sector scanning scheme.The average rate and effective rate of a single RF beam training scheme in the scenario where the number of users tend to infinity and the transmission tends to Lo S path propagation are analyzed.The derivation and simulation results show that as the number of users increases,the average rate of the SDU and SDD schemes approaches the exhaustive search method,and the SDD scheme is superior to the SDU scheme in terms of effective rate.Compared with the exhaustive method,SDU and SDD schemes can reduce beam training overhead.