WiFi capacity has been successfully doubled on a chip developed by Columbia University that uses just a single antenna
The engineers achieved this feat by implementing the first ‘on-chip RF circulator’ which allows both incoming and outgoing signals to be sent and received using just one antenna.
In the era of Big Data, the current frequency spectrum crisis is one of the biggest challenges researchers are grappling with and it is clear that today's wireless networks will not be able to support tomorrow's data deluge.
Today's standards, such as 4G/LTE, already support 40 different frequency bands, and there is no space left at radio frequencies for future expansion.
At the same time, the grand challenge of the next-generation 5G network is to increase the data capacity by 1,000 times.
The new duplex system enables simultaneous transmission and reception at the same frequency in a wireless radio by using switches to rotate the signal across a set of capacitors.
Full-duplex communication is of particular interest to researchers because of its potential to double network capacity, compared to half-duplex communications that current cell phones and WiFi radios use.
The technology has been in development for several years and has yielded a chip that combines the circulator with the rest of the chip which could allow for a WiFi receiver that is half the size of the traditional component making it ideal for implementation in smartphones and other mobile devices.
"Being able to put the circulator on the same chip as the rest of the radio has the potential to significantly reduce the size of the system, enhance its performance, and introduce new functionalities critical to full duplex," says PhD student Jin Zhou.
The team has built a prototype of their system, a silicon integrated circuit that included both their circulator and an echo-cancelling receiver.
"This technology could revolutionise the field of telecommunications," said Professor Harish Krishnaswamy who worked on the project.
"Our circulator is the first to be put on a silicon chip, and we get literally orders of magnitude better performance than prior work.
“Full-duplex communications, where the transmitter and the receiver operate at the same time and at the same frequency, has become a critical research area and now we've shown that WiFi capacity can be doubled on a nanoscale silicon chip with a single antenna. This has enormous implications for devices like smartphones and tablets."
The Krishnaswamy group is already working on further improving the performance of their circulator.
University of Washington researchers recently developed WiFi chips that consume 10,000 times less power than their traditional counterparts which could also replace Bluetooth as the low-power wireless transmission method of choice.