Massive MIMO (Multiple Input Multiple Output) is an enhancement to the 5G network whereby enormous antennas (i.e., as big as a refrigerator) are being placed on towers. Massive MIMO technology is one of the keys to unlocking better 5G data rates, throughput, and spectral efficiency. Indeed, massive MIMO accomplishes this by adding a much greater number of antennas on the tower base station.
The primary benefits of massive MIMO to the network and end users are i) capacity increases and ii) coverage improvements. Ultimately, better capacity and coverage lead to a superior user experience. At the same time, massive MIMO reduces wireless network interference, which further improves the user experience.
Capacity Enhancements with Massive MIMO
Massive MIMO enhances network capacity by enabling 5G deployments in the higher frequency ranges of sub-6 GHz spectrum (e.g., 3.5 GHz frequency). Additionally, massive MIMO uses Multi-User MIMO (MU-MIMO) technology. Indeed, MU-MIMO is where the network serves multiple users with the same time and frequency resources.
Coverage Enhancements with Massive MIMO
With massive MIMO, users will enjoy a more uniform experience across the 5G network, even at the tower cell site’s edge. Therefore, users receive higher data rate service almost everywhere. Moreover, three-dimensional beamforming enables dynamic coverage capabilities for users that are in motion. For example, users that are traveling in connected vehicles. Indeed, this three-dimensional beamforming adjusts the coverage to suit the user’s location.
Massive MIMO on Towers in 5G
Overall, the footprint, on the tower, that massive MIMO antennas occupy for 5G, will be similar in size to the individual antennas which it will be replacing. Specifically, within a massive MIMO antenna, there are 25 to 100+ smaller antennas embedded into the panel. Indeed, each one of those antennas can use different frequencies and transmit their beam to a very specific location.
In turn, this allows massive MIMO antennas to offer a dramatic increase in capacity. Furthermore, they allow carriers to use frequencies in a much more efficient manner (i.e., spectral efficiency).
Mid-Band Spectrum Deployments for 5G Networks
In a 5G environment, massive MIMO antennas are particularly applicable for carriers deploying mid-band spectrum on towers. This is because mid-band spectrum requires smaller individual antennas, on a tower. Massive MIMO antennas cluster many of those smaller individual antennas, used for mid-band deployments, into one panel. Therefore, it is possible to deploy one singular antenna on a tower.
As a reference point, the single massive MIMO antenna used to deploy mid-band spectrum, will be as large or larger, than the antennas used for 5G low-band spectrum on the 600 MHz frequency.
Technology Behind Massive MIMO for 5G
Massive MIMO uses multiple transmitters and receivers in a minimum 16×16 array to transfer more data. Additionally, semiconductor company Marvell, believes that 32×32 and 64×64 massive MIMO will be used more in denser populations. Specifically, these larger antenna arrays allow for greater network performance and coverage to handle data traffic demand in dense areas.
As an example, Ericsson offers a portfolio of 5G radios for massive MIMO for low-, mid- and high-band frequencies. Specifically, Ericsson’s massive MIMO offering is unique as it incorporates significantly more compute capability, closer to the radio, in the antenna. Effectively, this enhances uplink performance, meaning that better coverage, with fewer radios, is possible. Therefore, massive MIMO can increase network capacity using fewer radios.
Implementation of Massive MIMO for 5G
Ericsson is providing massive MIMO radios for T-Mobile’s ongoing 2.5 GHz mid-band spectrum roll-out. Indeed, massive MIMO antennas have begun to be deployed by carriers like T-Mobile. However, a lot more massive MIMO deployments will occur in the near future, following completion of the C-band auction.
Specifically, C-band Auction 107 is offering 280 MHz of spectrum in the 3.7 GHz to 3.98 GHz range. Indeed, carriers like Verizon and AT&T will likely purchase significant depth of this mid-spectrum. In turn, towers will facilitate C-band spectrum deployments for 5G, which will leverage massive MIMO technology.