Multiple antenna technology – MIMO – is used in Wi-Fi routers and 4G systems and normally involves up to four antennas. Using a flexible prototyping platform from NI based on LabVIEW system design software and PXI hardware, the Bristol configuration implements a Massive MIMO system with 128 antennas deployed at the base station.
The system used for the demonstration operates at a carrier frequency of 3.5GHz and supports simultaneous wireless connectivity to up to 12 single antenna clients. Each client shares a common 20MHz radio channel. Complex digital signal processing algorithms unravel the individual data streams in the space domain seen by the antenna array.
The demonstration achieved a bandwidth efficiency of 79.4bit/s/Hz, which equates to a throughput of 1.59Gbit/s in a 20MHz channel.
The demonstration hardware was provided to Bristol University as part of the Bristol Is Open programmable city infrastructure. Lund University, meanwhile, has a similar setup in the LuMaMi testbed, enabling researchers at both sites to work in parallel.
James Kimery, NI’s director of RF research and SDR marketing, commented: “With much discussion around 5G, NI is excited to work with top research institutions such as Bristol and Lund universities, and organisations like Bristol is Open to drive the standard forward. This Massive MIMO reference design system demonstrates the power and productivity researchers can achieve with NI tools and technologies.”
