Prototype 64-way antenna system saves power and spectrum

August 24, 2012 // By Nick Flaherty
US researchers have unveiled a new 64-way multi-antenna technology in Istanbul that could help wireless providers keep pace with the demands of data-hungry smartphones and tablets.

The Argos technology aims to dramatically increase network capacity by allowing cell towers to simultaneously beam signals to more than a dozen customers on the same frequency. The first implementation was described at the Association for Computing Machinery’s MobiCom 2012 wireless research conference in Istanbul.
Argos is developed by researchers from Rice, Bell Labs and Yale University and the prototype uses 64 antennas to allow a single wireless base station to communicate directly to 15 users simultaneously with narrowly focused directional beams.
In tests at Rice, Argos allowed a single base station to track and send highly directional beams to more than a dozen users on the same frequency at the same time, allowing carriers to increase network capacity without acquiring more spectrum.
“The key is to have many antennas, because the more antennas you have, the more users you can serve,” said Argos project co-leader Lin Zhong, associate professor of electrical and computer engineering and of computer science at Rice. The theory for multi-user beamforming has been around for quite some time, but implementing technology has proven extremely difficult. Prior to Argos, labs struggled to roll out prototype test beds with a handful of antennas.
“There are all kinds of technical challenges related to synchronization, computational requirements, scaling up and wireless standards,” he said. “People have really questioned whether this is practical, so it’s significant that we’ve been able to create a prototype that actually demonstrates that this works.”
Argos uses new techniques that allow the number of antennas on base stations to grow to unprecedented scales. The Argos prototype, which was built by Rice graduate student Clayton Shepard, uses an array of 64 antennas and off-the-shelf hardware — including several dozen open-access test devices called WARP boards that were developed at Rice’s Center for Multimedia Communications. In tests, Argos was able to simultaneously beam signals to as many as 15 users on the same frequency. For wireless carriers,