Hybrid analog-digital downlink beamforming for the massive MIMO system using uniform and non-uniform linear arrays | |
| Author | Zar Chi Phyo |
| Call Number | AIT RSPR no.TC-16-03 |
| Subject(s) | MIMO systems Radio--Antennas |
| Note | A research submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Telecommunications, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Abstract | In this paper, a hybrid analog-digital beamforming technique for downlink massive multiple input multiple output (MIMO) system is considered and also applying non-uniform linear array system to hybrid beamforming algorithm. The performances of fully analog beamforming, fully digital beamforming, and hybrid beamforming are to be examined. For this system, first we assume that channel state information is perfectly estimated at the base station and there is no communications between the users and also the communication channels to be Rayleigh flat-fading with additive white Gaussian distribution (zero mean and unit variance) and frequency selective fading. For this study, the zero forcing precoding technique is used for differentiating the performances among these three algorithms and furthermore, comparing the procession time among them. Moreover, by applying binomial and Dolph-Chebyshev array to hybrid beamforming to reduce the sidelobes level as well as maximize the directivity of array pattern. Simulation results show that the performance of hybrid beamforming is superior to fully analog beamforming whereas the performance of hybrid beamforming is very similar to that of fully digital beamforming. However, the number of RF chains used in fully digital beamforming is more than that of RF chains used in hybrid beamforming. The simulation results of applying non-uniform linear array to hybrid beamforming indicates that the performances increased significantly in Dolph-Chebyshev case than that of uniform linear arrays. In addition, the program running time reflecting the complexity of the systems show that the hybrid case can reduce it while achieves similar spectral efficiency to the fully digital one. Therefore, we can conclude that the hybrid analog-digital beamforming can approach the fully digital beamforming solutions, while requiring lower power complexity. |
| Year | 2016 |
| Type | Research Study Project Report (RSPR) |
| School | School of Engineering and Technology (SET) |
| Department | Department of Information and Communications Technologies (DICT) |
| Academic Program/FoS | Telecommunications (TC) |
| Chairperson(s) | Attaphongse Taparugssanagorn; |
| Examination Committee(s) | Teerapat Sanguankotchakorn;Nakamura, Shinichi; |
| Scholarship Donor(s) | Norway Ministry of Foreign Affairs; |
| Degree | Research Studies Project Report (M.Eng.) - Asian Institute of Technology, 2016 |