An Overview of MIMO Technology

4x4 MIMO and 2x2 MIMO refer to the number of antennas used for transmitting and receiving data in a Multiple-Input and Multiple-Output (MIMO) system. The first number (e.g., 4 or 2) represents the number of transmit antennas used to send data signals. The second number (e.g., 4 or 2) represents the number of receiver antennas used to receive data signals. MIMO technology is used in various wireless communication systems, such as MU-MIMO routers, Wi-Fi router antennas, and cellular networks to improve data transmission speed and reliability.

There's no strictly defined maximum for antenna configuration in massive MIMO, the technology thrives on utilizing a large number of Wi-Fi antenna elements at the base station compared to traditional MIMO systems. Commercially deployed massive MIMO systems typically use configurations in the range of 64x64. Researchers have explored and successfully tested configurations exceeding this, reaching up to 256x256 elements.

MIMO uses multiple Wi-Fi router antennas on routers and devices to transmit and receive data simultaneously. This boosts Wi-Fi speed, range, and reliability by overcoming signal interference and combining different data streams. The latest Wi-Fi 6 utilizes MIMO technology by focusing on Multi-User MIMO (MU-MIMO Wi-Fi) with a smaller number of antennas (typically up to 8) and improved efficiency.