增加天线才能解决移动设备的数据交换需求

Researchers from Rice University have just unveiled a new multi-antenna technology that could help wireless providers keep pace with the voracious（贪婪的） demands of data-hungry smartphones and tablets. The 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. Details about the new technology, dubbed Argos, were presented August 23 at the Association for Computing Machinery's MobiCom 2012 wireless research conference in Istanbul. Argos is under development by researchers from Rice, Bell Labs and Yale University. A prototype built at Rice this year uses 64 antennas to allow a single wireless base station to communicate directly to 15 users simultaneously with narrowly focused directional beams.

Thanks to the growing popularity of smartphones and other data-hungry devices, the demand for mobile data is expected to grow 18-fold within the next five years. To meet demand, wireless carriers are scrambling to boost network capacity by installing more wireless base stations and shelling out billions of dollars for the rights to broadcast on additional frequencies.

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. The upshot is that Argos could allow carriers to increase network capacity without acquiring more spectrum.

"The technical term for this is multi-user beamforming," said Argos project co-leader Lin Zhong, associate professor of electrical and computer engineering and of computer science at Rice. "The key is to have many antennas, because the more antennas you have, the more users you can serve."

Zhong said 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."