NI, UEdinburgh Partner on ‘LiFi’

National Instruments (NI) is collaborating with the University of Edinburgh to dramatically improve indoor wireless communications capacity using optics.

Professor Harald Haas, chair of mobile communications at the University of Edinburgh, is a pioneer in visible-light communications and spatial modulation and has been working for years on a concept nicknamed LiFi that uses visible light communication over a single-channel, point-to-point link. He and professor Cheng-Xiang Wang, head of the Advanced Wireless Technologies Lab at Heriot-Watt University, also recently used NI hardware and system design software to create the first working prototype showing spatial modulation techniques over a wireless radio frequency (RF) channel.

Haas now plans to combine these two technologies to create even higher-density optical wireless networks — called optical attocell networks — that will harness massive MIMO (multiple input, multiple output) gains in both the optical and RF domains for energy-efficient indoor wireless communications.

"We've known for a long time that decreasing cell size can significantly increase cellular capacity and user data rates, but it's not been clear how we could facilitate that given current spectrum, energy and interference limitations," Haas said. "RF wireless and optical wireless networks that work together using spatial modulation and massive MIMO approaches could allow us to effectively mitigate interference and significantly increase energy efficiency, coverage and capacity using existing infrastructure."

The Edinburgh team will use NI products to rapidly prototype a wireless test bed and build prototypes that operate beyond the rates of a commercial RF wireless system. The investigators recently achieved 3.5 Gb/s from a single-color LED, allowing them to create an ultrarealistic test bed. The advances are seen as a step toward fifth-generation (5G) wireless communications.

For more information, visit: www.ni.com or http://visiblelightcomm.com