How is Massive MIMO technology being considered as one of technologies for inclusion in the 5G specifications?

Massive MIMO is one of the candidate technologies being considered for inclusion in the 5G specifications and has shown real progress in the lab. For those not familiar with the concept, Massive MIMO takes MIMO to an extreme using hundreds of antennas at the base station utilizing full spatial multiplexing - multiple data streams are transmitted at the same time using the same frequency. Ideally, base stations could be constructed with hundreds of low-cost antennas rather than the sectored high power remote radio heads widely used today to enhance coverage, improve power efficiency and attain higher spectral efficiency. Last year, researchers at the University of Bristol in the UK and Lund University in Sweden demonstrated a 128 antenna Massive MIMO base station prototype (128 receive and 128 transmit antennas) to produce an astounding 146 b/s/Hz spectrum efficiency mark in just 20 MHz of spectrum.

British Telecom (BT), the largest provider of telecommunications services in the UK, took note of this work and reached out to Professors Mark Beach and Andrew Nix at Bristol to test their Massive MIMO prototype in more demanding environments. Instead of a controlled lab, BT sought to test the system in a variety of different scenarios including both indoor and outdoor settings. The Bristol team took their system on the road to BT’s Adastral Park campus where the initial experiments were staged in a large exhibition hall.