Radio spectrum is finite, while demand for wireless capacity keeps climbing with industrial digitalisation, autonomous vehicles and ever more connected users. Researchers at Lund University's Faculty of Engineering have responded by building LuLIS, the Lund University Large Intelligent Surface, and demonstrating what they describe as a world first: a distributed network of 256 digitally beamformed antennas, spread across different locations, whose signals and data are coordinated in real time.
The testbed consists of sixteen programmable panels of sixteen antennas each, built on AMD radio-frequency hardware, with a modular, software-controlled design that lets researchers reconfigure how data is transmitted. Getting it running meant solving signal synchronisation and distributed computation problems that purely theoretical studies rarely expose. The project, involving professors Ove Edfors and Liang Liu and a team of doctoral students, was funded chiefly by the Swedish Foundation for Strategic Research, with Ericsson and Sony as industry partners from the outset.
Lund has form here: its earlier massive MIMO testbed, LuMaMi, supported 22 simultaneous users in a single frequency band and set a spectral efficiency world record with the University of Bristol in 2016, work that fed into today's 5G standards. The new system targets 32 simultaneous users in the near term, with a longer-term ambition of beating the 2016 record tenfold, giving researchers and industry a realistic environment in which to shape 6G before it is standardised.