New world record in 5G wireless spectrum efficiency

A team of engineers from the University of Bristol’s Communication Systems and Networks (CSN) Group and the Department of Electrical and Information Technology at Lund University in Sweden has smashed the world record for 5G wireless spectrum efficiency it set earlier this year.

Using 128 base station antennas, the team served 22 users on the same time-frequency resource, equating to a rate of 145.6 (bits/s)/Hz on a single 20MHz radio channel. The previous record was 79.4 for 12 users, also using 128 antennas. Both trials were conducted in the atrium of Bristol’s Merchant Venturers Building.

This was achieved using massive MIMO (multiple-input multiple-output) arrays, which are cellular base stations with dozens of antennas deployed at the base station.

Professor Andrew Nix, Head of the CSN Group and Dean of Engineering, said: “Unlike at mmWave [millimetre-wave] frequencies, below 6GHz, very little new spectrum is anticipated for 5G services. To meet capacity demands in the microwave bands the only solution is to deploy technologies offering radically enhanced spectral efficiency; hence the global importance of massive MIMO and the significance of smashing through the 100 bits/sec/Hz barrier.”

Liang Liu, Associate Professor with the Faculty of Engineering at Lund University, said: “In addition to investigating spectrum efficiency gains, an initial power control algorithm was tested, users were placed in different locations and use of the equipment over night to obtain calibration data for comparison purposes with the Lund set-up”

Bristol University is at the forefront of 5G research in the UK, with this latest achievement following the development of a closed 5G network in the city and collaborations with Keysight Technologies to try and understand the nuances of mmWave frequencies.