Collaborative research taking place between the Universities of Bristol and Lund, National Instruments and BT has set up field trials of a massive MIMO system working in a large indoor environment.
The aim was to test massive MIMO spatial multiplexing indoors and improve the understanding of massive MIMO radio channels under mobile conditions with untethered devices.
As a result of the trail, the researchers believe this technology could offer spectrum efficiency figures in excess of the 100 bits/s/Hz mark.
This would represent a ten-fold increase in capacity compared with LTE mobile systems in operation today.
It is expected that techniques such as massive MIMO will become a crucial part of future5G networks.
Mark Beach, Professor of Radio Systems Engineering at the University of Bristol, writes:
“We are delighted to be collaborating with BT. Massive MIMO is a key technology for 5G and the research team’s achievements last year with massive MIMO arrays, which are cellular base stations with more than 100 antennas, demonstrates that this technology could deliver ultra-fast data rates to high densities of smartphones and tablets.”
Initial experiments took place in BT’s large exhibition hall and used 12 streams in a single 20MHz channel to show the real-time transmission and simultaneous reception of ten unique video streams, plus two other spatial channels demonstrating the full richness of spatial multiplexing supported by the system.
The system was also shown to support the simultaneous transmission of 24 user streams operating with 64QAM on the same radio channel with all modems synchronising over-the-air.
It is believed that this is the first time such an experiment has been conducted with truly un-tethered devices, from which the team were able to infer a spectrum efficiency of just less than 100bit/s/Hz and a sum rate capacity of circa two Gbits/s in this single 20MHz wide channel.
Professor Tim Whitley, Managing Director, Research and Innovation at BT, added:
“Massive MIMO has the potential to significantly boost available data rates in future5G mobile networks, and we’re pleased to be able to explore that potential with leading academics in the field at the University of Bristol.”
The research team, consisting of five PhD students from Bristol’s EPSRC Centre for Doctoral Training in Communications and a researcher from Lund University, under the leadership of Professor Mark Beach, worked with the BT research team, led by Ian Mings, to assess the performance of a 128 element Massive MIMO system operating at 3.5 GHz at BT’s Adastral Park campus.