@ARTICLE {33055,
author={D.  Borges and PMC Carvalho and R. Dinis and M.B. Beko},
doi={10.3390/electronics10141667},
journal={Electronics},
title={Massive MIMO Techniques for 5G and Beyond—Opportunities and Challenges},
year={2021},
month={July},
volume={10},
number={14},
pages={1667-1667},
ISSN={}
}