MIMO
Basics of Multiple-Input, Multiple-Output Antenna Systems
MIMO is a wireless communication antenna technology that utilizes multiple antennas at both ends of the communication circuit, i.e., at the source or transmitting end and at the receiving or destination end.
By combining the antennas at each end of the communication line, data is able to travel over many signal paths simultaneously, which improves radio transmission capacity and optimizes data speed while at the same time minimizing errors.
Multiple antennas equate to higher speeds, and wireless devices with two antennas can expect to have speeds of 300 Mbps, while devices with three antennas can achieve speeds of 600 Mbps. Older wireless devices use Single Input, Single Output (SISO) technology and can thus only send and receive single data streams at a time.
MIMO utilizes a radio wave phenomenon known as multipath, where transmitted signals bounce off physical objects to reach the receiving antenna multiple times and at slightly different angles.
The process of creating many versions of a signal enhances the likelihood that data will reach its destination unaffected by fading, which increases the signal-to-noise ratio and error rate.
MIMO technology helps ensure stable connections and less congestion by boosting the capacity of RF systems.
All 802.11n wireless devices support MIMO, giving them an edge over devices without 802.11n as far as data rates are concerned. For MIMO to be implemented, both communicating parties — the transmitter and receiver — must support MIMO.
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MIMO technology is being widely adopted for WI-FI and 4G LTE/5G networks in a variety of applications, including WLANs, broadcasting, and even law enforcement.
MIMO is often utilized for high-bandwidth communications where it’s imperative that there be no interference from Radio Frequency and Microwave systems.
MIMO technology supersedes and builds on older antenna technologies like MISO (multiple input, single output) and SIMO (single input, multiple output).
MIMO and LTE
MIMO played a key role in WiMAX (Worldwide Interoperability for Microwave Access), a wireless broadband technology. LTE utilizes MIMO for transmit diversity, spatial multiplexing, and single-user or multi-user systems, with speeds upwards of 100 Mbps. The use of MIMO in LTE ensures higher data rates and more reliability in data transmission.
MIMO and 5G
5G technology is a prominent example of MIMO utilization. 5G MIMO systems use numerous small antennas to boost bandwidth for users and support more users per antenna. This is unlike 3G and 4G, whose main idea was to boost transmission rates. For supporting multiple devices, 5G massive MIMO uses TDD (Time Division Duplex), which has numerous advantages over the slightly older FDD (Frequency Division Duplex) employed by 4G.
MIMO and Beamforming
Beamforming is where broadcast data is pointed and focused on a particular user or receiving device rather than being spread over a large area. This radio frequency management technique maximizes the signal’s power at the receiver since very little of it is dissipated over a vast geographical area.
3D beamforming forms and directs vertical and horizontal beams at the user, preventing interference with proximate wireless signals and staying with the receiving device as it moves around a given area.
Multi User MIMO vs. Single User MIMO
MIMO comes in two distinct forms: single-user and multi-user MIMO.
In single-user MIMO (SU-MIMO) systems, data streams can only interact with one user on the network at a given time, i.e., multiple data streams are sent but only to one receiving device.
In SU-MIMO systems, issues like latency and delays are rife, particularly when multiple users attempt to use the network at the same time, particularly for bandwidth-intensive tasks like video conferencing, which tend to chock the data stream.
With Multi-User MIMO (MU-MIMO), on the other hand, multiple streams are sent to multiple users or devices simultaneously. Latency and delays are rare and transient (though they might not be entirely non-existent).
Influence and Advantages of MIMO technology
- In MIMO, signals are bounced and reflected, thus enabling stronger signals even for users who are not in a clear line of sight.
- Because MIMO supports greater throughput, high-bandwidth tasks like video and other ‘heavy’ content can travel faster over a network without the previously attendant problems of lag, choke, and latency.
- The use of multiple data streams decreases the chances of lost packets, which can be particularly harmful to audio and visual applications, thus improving the vision and auditory quality of received content. This goes a long way toward improving the general user experience.
- MIMO enhances and extends network coverage, and users can enjoy high-speed data rates wherever they are, including on the fringes of signal coverage areas, thanks to 3D beamforming, which adapts to the user’s movement and location.
