The National Science Foundation awarded $2.4 million grant to Rice University researchers to conduct what’s billed as the most extensive experimental research that entails installation and use of 100 or more multiple-use MIMO antennas on wireless network base stations.
Known in the industry as massive multi-user MIMO or massive MU-MIMO, doing so could result in transmission of concentrated beams of wireless data to individual network users, Rice highlights in a news release.
The experiments, which are to take place at Rice’s Houston campus, could result in massive multi-user MIMO being used by wireless network carriers in anticipated 5G infrastructure rollouts.
“Early tests of many-antenna technology at Rice and elsewhere suggest that wireless carriers could use this technology to serve many times more data than can be served with today’s 4G networks,” principal investigator Lin Zhong was quoted as saying. Zhong is an associate professor of electrical and computer engineering and computer science at Rice U.
“There are still many questions about how to scale this technology for real-world implementation,¨ however, he added. Those are the challenges we’ll be tackling with the new research.”
Zhong’s Efficient Computing Group will make use of the ArgosNet multiple-antenna experimental test-bed they have already built with NSF funding. As many as six programmable wireless base stations, each with 100 or more MIMO antennas, will eventually be incorporated into ArgosNet.
Today’s wireless 4G base stations can only communicate with up to four individual users at a time on a given frequency, Rice news reporter Jade Boyd points out in the article. In order to serve thousands simultaneously, they divide their time and frequency to serve tiny slices of data to individual users every few milliseconds.
Wireless network performance suffers when too many users are connected at the same time. Such occurrences are expected to increase in frequency given forecast growth in broadband wireless network penetration and device usage.
Industry players and analysts are predicting explosive growth in mobile data usage will continue even as current statistics highlight the trend. Ericsson predicts total mobile data traffic will grow at a 40 percent CAGR from 2015-2021, rising from a current 1.3 to 9 exabytes in the November 2015 North America Ericsson Mobility Report.
“Large-scale multi-user MIMO technology is a key enabler in meeting the 1,000x data challenge — that of increasing spectrum efficiency by a factor of 1,000 when compared to current 4G data networks,” NSF program director Thyaga Nandagopal highlighted.
“The National Science Foundation has funded basic research in this area for several years now, and this project will advance this research to the next level by addressing the system-level challenges that can hinder the realization of this technology’s full potential.”
Making use of 100 or more MIMO antennas and continuously computing each users exact location, Rice U.’s ArgosNet beams data directly to numerous users simultaneously on the same frequency. This would multiply the number of wireless network users base stations can serve simultaneously on a single frequency band many times.
A lot of computing power is needed to process and analyze all the necessary data and form and re-form data beams to communicate with end-users, however, Zhong pointed out. Reducing interference poses another challenge as required data must be broadcast regularly from user devices.
In addition, Zhong’s research team is exploring ways to make ArgosNet compatible with smartphones and other mobile and wireless devices.
ArgosNet’s modular design will facilitate the Rice team’s experimental research, PhD student Clayton Shepard noted. “ArgosNet is a very flexible platform. We’ve designed it to work like Lego blocks; we can add or subtract antennas and other components to construct any kind of node that we want. The wireless test units also can be configured to act like everything from a laptop to a wireless handset.”
That flexibility will enable researchers to more efficiently evaluate the computing overhead needed for massive multi-user MIMO beam formation and reformation, as well as interference from pilot signal traffic and how massive MU-MIMO might be implemented along with wireless network ´densification´ initiatives being carried out by carriers.
In new market research, ABI forecasts the small-cell market will grow at a 43 percent CAGR out to 2020 as major carriers ramp up efforts to increase wireless network penetration, quality of service and usage in cities and densely populated urban areas.
