Earlier this year, Stanford University researchers created a full-duplex radio that allowed wireless signals to be sent and received simultaneously, thereby doubling the speed of existing networks. Using the same approach, researchers at Rice University have now developed similar full-duplex technology that would effectively double the throughput on mobile networks without the addition of any extra towers.
Currently, mobile phones use two different frequencies to provide two-way communications – one to send transmissions and another to receive. This is because the strength of the transmission drowns out any incoming signal on the same frequency. While it was long thought impossible to overcome this problem, in 2010 Ashutosh Sabharwal, professor of electrical and computer engineering at Rice, and colleagues Melissa Duarte and Chris Dick, published a paper showing that full-duplex was possible.
The trick lay in canceling out the transmitted signal at the source so an incoming signal on the same frequency could still be heard. Like the Stanford approach, the technology developed by the Rice researchers achieves this by employing an extra antenna at the source.
‘We send two signals such that they cancel each other at the receiving antenna – the device ears,’ Sabharwal said. ‘The canceling effect is purely local, so […]