Open AccessBeam combination scheme for multi‐user massive MIMO systems
Author(s) -
Zhang Fangchao,
Sun Shaohui,
Gao Qiubin
Publication year - 2017
Publication title -
electronics letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.375
H-Index - 146
ISSN - 1350-911X
DOI - 10.1049/el.2016.4704
Subject(s) - telecommunications link , beamforming , channel state information , computer science , overhead (engineering) , base station , mimo , electronic engineering , user equipment , interference (communication) , channel (broadcasting) , real time computing , engineering , telecommunications , wireless , operating system
Channel state information (CSI) at the base station (BS) is crucial to fully exploit the advantages of massive multiple‐input multiple‐output (MIMO) systems. In frequency division duplexing systems, CSI is obtained through downlink channel estimation and uplink CSI feedback. The conventional CSI acquisition scheme, which has been designed based on the beam selection principle, suffers from severe multi‐user interference when same beamforming vector is selected for different user equipments (UEs), and the spatial richness of the channel cannot be captured by the selected beamforming vector for the rich scattering environment. To address such issues, a beam combination scheme is proposed by combining multiple selected beamforming vectors for each UE, where the beam combination process is divided into wideband beam group construction and subband combination coefficients acquisition. Simulation results demonstrate that the proposed scheme could achieve considerable increase in the system throughput while maintaining acceptable feedback overhead.