Indian origin engineer develops technology for simultaneous Wifi transmission and reception

Harish Krishnaswamy, associate professor of electrical engineering, Columbia University 
A team of Columbia University researchers believes that enabling reliable and efficient full duplex wireless communication is a task best addressed at the chip level. The researchers, led by Harish Krishnaswamy, an associate professor of electrical engineering, have developed full-duplex radio integrated circuits that can be implemented in nanoscale CMOS to enable simultaneous transmission and reception on the same frequency. "Having a transmitter and receiver use the same frequency offers the potential to immediately double network data capacity," Krishnaswamy says. "Our work is the first to demonstrate an IC that can receive and transmit simultaneously," he says. CMOS is the dominant technology used for radio ICs inside phones and other radio-equipped mobile devices. The biggest challenge the team faced during its research was canceling transmitter echo, a phenomenon that makes usable full duplex impossible. "What you really need to do is to cancel-out that echo to the point where it's eliminated almost perfectly and the residual echo is extremely small - smaller than the received signal, the desired signal - that you're trying to receive from the distant cell tower," he says. Since the echo is over a billion times more powerful than the received signal, echo cancellation circuits must operate highly precisely. "We need echo cancellation circuits that are something like one-part-per-billion-level accurate," Krishnaswamy explains. Such precision is difficult to achieve in software alone without killing overall device performance. "This really is something that needs to be done in hardware," Krishnaswamy says. "That level of precision in the echo cancellation, and the need to handle such a loud echo, cannot be done purely in signal processing." To achieve optimal quality, the researchers applied multiple layers of echo cancellation to their software. "The echo is at least a billion to 10 billion times more powerful than the signal that we're trying Columbia to receive, so basically you want to cancel that factor, and that's hard to do with one signal echo canceller," Krishnaswamy says. "So the way these full duplex systems are likely to be successful is to have multiple layers of echo cancellation, just hitting that echo canceling again, and again, and again. Krishnaswamy and doctoral student Jin Zhou are now testing the full-duplex technology on various nodes to understand exactly what gains might be possible at the network level. "We are looking forward to being able to deliver the promised performance improvements," Krishnaswamy says. Source
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Scientists Develop New Ways to Solve the Mysteries of Mars

Credit: ESA

Scientists hope to finally reveal how and why Mars has changed so dramatically through time, from an ancient world of rivers and oceans, to the dry and dusty planet that we see today.

Dr James Darling, at the University of Portsmouth, is leading a three-year study which aims to get to the bottom of what happened to Earth’s nearest neighbour, the so-called red planet.

He has been awarded £ 342,000 funding from the Science and Technology Facilities Council (STFC).

Dr Darling is an expert in isotope geochemistry in the University’s School of Earth and Environmental Sciences.

He said: “Without a robust timeline of the geological events on Mars, we can’t understand how or why it changed from an ancient world of rivers, oceans, volcanoes and meteorite impacts to the cold, dry planet that we see today.

“This project will help to reveal how the planet has evolved through new radiometric age dating of martian meteorites. Previously, this has been very difficult because these rocks have experienced extreme deformation during meteorite impact events, which can disturb the isotopic systems used for dating. We can now overcome this by identifying microscopic deformation features in crystals that can be avoided or targeted for radiometric dating using the latest techniques in mass spectrometry.

“I am excited to see where this will lead.”

The project begins in April, 2019.

Dr Darling will lead a multidisciplinary team of scientists, including partners from other leading universities in the UK, Canada and Germany, to test how the crust and mantle of Mars have evolved and influenced the surface and atmosphere.

The same questions are top of scientific wishlist of ongoing and new spacecraft missions, including NASA InSightand Mars 2020 Rover and the ESA ExoMars 2020 mission.

Astrophysicist Professor Bob Nichol, acting Pro-Vice Chancellor for Research and Innovation at the University of Portsmouth, said: “Congratulations to James in gaining such competitive funding. While the red planet is a bit close for my studies, I am fascinated by our quest for answers about life in the Universe which probably means locating water on other planets. Looking at what happened on Mars first makes total sense.”

Contacts and sources: University of Portsmouth, Source:
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