Part 1 explains who originated massive MIMO and how it works

IEEE Fellow Thomas Marzetta is well known for originating the 5G massive MIMO (multiple-input multiple-output) technology in 2006, which telecom experts consider to be one of the cornerstones of 5G wireless communications. This technology uses many small, individually controlled, low-power antennas to directly beam streams of information, simultaneously and selectively, to large groups of wireless users.

Although Marzetta liked the term “large scale antenna systems” (LSAS), the Bell Labs Director of Research recommended avoiding the term “MIMO.” Later, because everyone else was calling the technology massive MIMO, Marzetta did as well.

Everyone wants more spectrum and MIMO multiplies a radio link’s number of users by using multiple transmission and receive antennas to take advantage of multi-path propagation (Figure 1). MIMO enables simultaneously sending and receiving more than just one data signal over a radio channel by using multi-path propagation. For example, MIMO may have a two transmit and two receiver (2T2R) format; this is low-capacity 2×2 MIMO. There is also a medium capacity 4×4 MIMO that is a 4T4R version.

Massive MIMO is an extension of MIMO and provides advanced antenna technology with multiple antennas on base stations (Figure 2), to serve multiple end-user devices simultaneously within one time interval. This advanced antenna technology enhances spectral efficiency, network capacity, and coverage with easily achievable data rates.

Antenna layers in 5G massive MIMO are quite a bit higher than the MIMO in 4G LTE. Massive MIMO deploys tens or even hundreds of antenna elements within a single antenna panel. For example, a 64×64 massive MIMO high-capacity antenna configuration has already been deployed by some 5G network vendors, and 256×256 arrays are also possible.

Transmitter and receiver diversity, spatial multiplexing, and beamforming are the foundation which greatly improves signal reliability and data throughput. They also and reduce interference.

COVID-19 effects on massive MIMO
As COVID-19 continues to plague the world, many countries are considering lockdowns again. This will restrict and slow down 5G deployment. Industries such as transportation, automotive, and logistics are, however, still going to be significant growth areas for massive MIMO. North America will feel the greatest impact for the temporary slowdown in growth, since the massive MIMO market in that region is most significant. The good news is that 5G massive MIMO will continue to grow, despite the COVID-19 bug, especially in the Southeast Asia Pacific area, and as well as in Europe.

Stay tuned for more technical information on massive MIMO technology next month in Part 2.

Steve Taranovich is the author of Guardians of the Right Stuff. He’s an experienced technical writer and former editor-in-chief with a demonstrated history of working in the writing and editing industry. His skills include in analog electronics, space-related electronics, audio, RF communications, and power management. Steve holds BSEE and MSEE degrees from NYU Polytechnic School of Engineering (now NYU Tandon School of Engineering).