Overview
MIMO stands for Multiple-Input Multiple-Output. While traditional base stations might have 2 or 4 antennas, a Massive MIMO base station can have 64, 128, or even more. This allows the base station to send and receive many data streams simultaneously to multiple users.
How it Works
By using many antennas, the base station can focus the radio signals into narrow 'beams' directed at specific users (beamforming), rather than broadcasting the signal in all directions. This reduces interference and significantly increases the amount of data that can be transmitted.
Importance
Massive MIMO is one of the key technologies that allows 5G to achieve its massive increase in capacity and speed compared to 4G.