Research On Feasible Massive MIMO Technology

The technology of Massive MIMO is one of the key technologies in 5G system. Antenna array topologies have a direct impact on the performance of Massive MIMO system. Therefore, the research of antenna array topologies is one of the key topics. The paper researches the large-scale modular hybrid antenna array first. The array is made up by low cost and unified smaller modules. The combination of modules is flexible. We analyze the structure of the modular array in detail.If the array elements spacing is small, the technology of beamforming can use the wave interference principle to form the beam with a strong direction. It can improve the performance of system. The paper studies the analog beamforming and digital beamforming respectively. With the limited performance, the analog beamforming can't meet the complicated requirement in beamforming. Although the digital beamforming can form the ideal beam, the cost of hardware and the complexity in baseband processing is high. The paper mainly forces on the hybrid beamforming which is the combination of analog beamforming and digital beamforming.We researches the scheme of full-connected hybrid beamforming and proposes the sub-array iterative hybrid beamforming. By this way, it can reduce the complexity and costs.Except exploring the feasible technology in Massive MIMO system,evaluating the influence of using large-scale antenna array to the current system is also an important work before the implementing the technology of Massive MIMO. We construct a system of simulation to assess the adjacent channel interference with the increase of antennas. The results of evaluation provide the reference to allocate spectrum and solute the interference.