The notation used in MIMO (Multiple Input Multiple Output) technology, such as 2x2, 4x2, or 2x4, specifies the number of transmit and receive antennas involved in the communication system. The first number represents the amount of transmitting antennas, and the second number represents the amount of receiving antennas.
Each MIMO configuration offers a trade-off between data throughput, signal quality, and reliability, allowing network equipment and devices to be optimized for different scenarios and user needs.
Here's what each configuration means:
- 2x2 MIMO: This configuration has 2 transmitting antennas and 2 receiving antennas. It can double the data rate compared to a single antenna (SISO - Single Input Single Output) under ideal conditions or significantly increase the reliability of a connection.
- 4x2 MIMO: This setup involves 4 transmitting antennas and 2 receiving antennas. The extra transmitting antennas can be used to send more data streams or to provide additional diversity and robustness to the signal.
- 2x4 MIMO: This configuration has 2 transmitting antennas and 4 receiving antennas. While it may not increase the peak data rate beyond what 2x2 MIMO can achieve (since the number of data streams is limited by the lesser of the transmit and receive antennas), having more receiving antennas can significantly improve signal robustness and quality, making the connection more reliable, especially in challenging environments with lots of interference or signal fading.