MIMO technology is a technology used in antennas for wireless communication, such as routers, notebooks, smartphones and tablets🇧🇷 The term means “multiple inputs, multiple outputs” (“multiple input, multiple output”🇧🇷 MIMO uses multiple antennas connected on the same device, which work together to minimize errors, optimize data speed and improve transmission capacity.
Antennas emit multiple versions of the same signal, which increases the chances that data will reach the receiver unaffected. This increases signal strength relative to ambient noise (“signal-to-noise ratio”) and creates a more stable connection with less congestion.
MIMO technology is used in Wi-Fi, 4G LTE and 5G networks. It was incorporated into the Mobile Broadband Standard – the set of standards for mobile devices – starting with version 8 and is compatible with all devices that use the 802.11n wireless standard.
MIMO is a recent solution to wireless communication problems and its functions were built upon other earlier technologies such as MISO (“multiple input, single output”) and SIMO (“single input, multiple output🇧🇷
Advantages of MIMO technology
MIMO brings two major advantages to the home router:
- Increased baud rate: one device can receive data from multiple antennas, which means that large content such as videos are transmitted faster, reducing clipping;
- Fewer interruptions: As the baud rate is higher, devices connected to the router wait less time to receive data.. That increases the number of devices that the router can serve satisfactorily, reducing latency.
SU-MIMO and MU-MIMO
MIMO is divided into two basic subtypes: single user (“single user”, SU) and multiple users (“multiuser”, MU).
In the first type, data can only interact with one device and one network at the same time. Nonetheless, the problem with SU-MIMO is that it causes disruption in data transmissions when multiple devices try to use the network at the same time. This results in a drastic increase in latency, which delays data delivery.
Meanwhile, MU-MIMO is capable of transmitting multiple sets of data to multiple devices at the same time.
MIMO and cellular telephony
MIMO innovations were key to the development of LTE. The protocol uses MIMO and a technique called “octagonal frequency division multiplexing” (OFDM), which can increase the transmission speed beyond 100 mbps. These rates are double what was possible with the 802.11a WiFi standard.
With MIMO technology, LTE data transmissions are more reliable. This data is separated into packets that are sent over the air to a receiver that already knows how they operate.
MIMO and 5G technology
MIMO capabilities have also been built into 5G technology, which is a way to use the full potential of today's devices and networks.
5G systems with MIMO use multiple small antennas to enhance users' broadband signal. This is something that did not happen with previous technologies – 3G and 4G🇧🇷 Furthermore, it also results in an increase in the number of users allowed per antenna.
Fourth-generation MIMO used frequency spectrum splitting (FDD) technology to support multiple simultaneous users, but this was inefficient because it used too much spectrum. already in In the fifth generation, this feature has been replaced by time spectrum division (TDD), which allows for a greater number of simultaneous users by using the same frequency for connections and separating them into time slots.
This then allowed, with a lower frequency, more data to be transferred to more devices. As a result, 5G networks have become closer to home Wi-Fi router technologies, which employ both TTD and FDD, as well as enabling technologies such as beamforming and MU-MIMO on 5G.
5G MIMO also employs a technique called 3D beamforming, which is used to maximize the receiver's signal by focusing data transmission to specific users rather than a wide area. In 5G, this technology is able to adapt to the 3D movements of connected devices, detecting whether they are in a position above or below the sending router. This helps to focus even more on outputting data.
The future of MIMO technology
The benefits provided by the use of MIMO technology were fundamental to the evolution of wireless communication. The technology continues to be used in current and developing protocols and its impacts will affect the near future of the wireless.
In short, the influences of MIMO are:
- High network capacity: data is carried over to a larger number of concurrent users. This means that more people can use the network without loss of quality;
- Greater coverage: connections remain fast even if the devices are far from the signal-emitting router. This is possible with 3D beamforming, which allows the coverage to adapt to the user's movement;
- Improved user experience: O A stronger, better-quality signal allows the device to be used for a variety of heavy-duty tasks – such as watching videos and uploading content – faster and easier. It also decreases the number of lost signals, which helps speed up the task.