Scientists propose data encoding method for the 6G standard

June 11, 2020

Researchers around the world are working on ways to transfer data in the terahertz (THz) range, which would make it possible to send and receive information much faster than what is allowed by today's technology. But the issue they're facing is that it is much more difficult to encode data in the THz range than in the GHz range, which is currently used by 5G tech. A group of scientists from ITMO University have demonstrated the possibility of modifying terahertz pulses in order to use them for data transmission. An article on this subject was published in Scientific Reports.

Telecommunications companies in advanced economies are beginning to adopt the new 5G standard, which will endow users with previously-unseen wireless data transfer speeds. Meanwhile, as the world makes its first steps towards this new generation of data networks, scientists are already at work on its successor. "We're talking about 6G technologies," says Egor Oparin, a staff member of ITMO University's Laboratory of Femtosecond Optics and Femtotechnologies. "They will increase data transfer speeds by anywhere from 100 to 1,000 times, but implementing them will require us to switch to the terahertz range."

Today, a technology for simultaneous transfer of multiple data channels over a single physical channel has been successfully implemented in the infrared (IR) range. This technology is based on the interaction between two broadband IR pulses with a bandwidth measured in tens of nanometers. In the terahertz range, the bandwidth of such pulses would be much larger - and so, in turn, would be their capacity for data transfer.

But before we begin to consider 6G technology, scientists and engineers will need to find solutions to numerous crucial issues. One such issue has to do with ensuring the interference of two pulses, which would result in a so-called pulse train or frequency comb used to encode data.

"In the terahertz range, pulses tend to contain a small number of field oscillations; literally one or two per pulse," says Egor Oparin. "They are very short and look like thin peaks on a graph. It is quite challenging to achieve interference between such pulses, as they are difficult to overlap."

A team of scientists at ITMO University has suggested extending the pulse in time so that it would last several times longer but still be measured in picoseconds. In this case, the different frequencies within a pulse would not occur simultaneously, but follow one another in succession. In scientific terms, this is referred to as chirping or linear-frequency modulation. However, it comes with another challenge: although chirping technologies are quite well-developed in regards to the infrared range, there is a lack of research on the technique's use in the terahertz range.

"We've turned to the technologies used in the microwave range," says Egor Oparin, who is a co-author of the paper.

"They actively employ metal waveguides, which tend to have high dispersion, meaning that different emission frequencies propagate at different speeds there. But in the microwave range, these waveguides are used in single mode, or, to put it differently, the field is distributed in one configuration, in a specific, narrow frequency band, and, as a rule, in one wavelength. We took a similar waveguide of a size suitable for the terahertz range and passed a broadband signal through it so that it would propagate in different configurations; because of this, the pulse became longer in duration, changing from two to about seven picoseconds, which is three and a half times more. This became our solution."

By using a waveguide, researchers have been able to increase the length of the pulses to a duration that is necessary from a theoretical standpoint. This made it possible to achieve interference between two chirped pulses that together create a pulse train. "What's great about this pulse train is that it exhibits a dependence between a pulse's structure in time and the spectrum," says the scientist. "So we have temporal form, or simply put field oscillations in time, and spectral form, which represents those oscillations in the frequency domain. Let's say we've got three peaks, three substructures in the temporal form, and three corresponding substructures in the spectral form. By using a special filter to remove parts of the spectral form, we can "blink" in the temporal form and the other way around. This could be the basis for data encoding in the terahertz band."
-end-


ITMO University

Related Technology Articles from Brightsurf:

October issue SLAS Technology now available
The October issue of SLAS Technology features the cover article, 'Role of Digital Microfl-uidics in Enabling Access to Laboratory Automation and Making Biology Programmable' by Varun B.

Robot technology for everyone or only for the average person?
Robot technology is being used more and more in health rehabilitation and in working life.

Novel biomarker technology for cancer diagnostics
A new way of identifying cancer biomarkers has been developed by researchers at Lund University in Sweden.

Technology innovation for neurology
TU Graz researcher Francesco Greco has developed ultra-light tattoo electrodes that are hardly noticeable on the skin and make long-term measurements of brain activity cheaper and easier.

April's SLAS Technology is now available
April's Edition of SLAS Technology Features Cover Article, 'CURATE.AI: Optimizing Personalized Medicine with Artificial Intelligence'.

Technology in higher education: learning with it instead of from it
Technology has shifted the way that professors teach students in higher education.

Post-lithium technology
Next-generation batteries will probably see the replacement of lithium ions by more abundant and environmentally benign alkali metal or multivalent ions.

Rethinking the role of technology in the classroom
Introducing tablets and laptops to the classroom has certain educational virtues, according to Annahita Ball, an assistant professor in the University at Buffalo School of Social Work, but her research suggests that tech has its limitations as well.

The science and technology of FAST
The Five hundred-meter Aperture Spherical radio Telescope (FAST), located in a radio quiet zone, with the targets (e.g., radio pulsars and neutron stars, galactic and extragalactic 21-cm HI emission).

AI technology could help protect water supplies
Progress on new artificial intelligence (AI) technology could make monitoring at water treatment plants cheaper and easier and help safeguard public health.

Read More: Technology News and Technology Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.