Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

ETH Zurich researchers test high-speed WLAN network

13.03.2008
Performance boost for wireless networks

According to the communication theory, only a limited amount of data can be transmitted within a given bandwidth for wireless communication. Ever since these limits were revealed 60 years ago, we have been trying to reach the boundaries determined by physics as efficiently as possible. In light of the growing significance of cellular phone networks and WLAN connections, scientists are seeking new ways to transfer more data than ever before – after all, transmission capacities are in short supply and, therefore, a valuable commodity.

Messages from the babble

Thanks to so-called MIMO technology, which stands for “Multiple Input Multiple Output”, it is possible for several transceivers to communicate with each other on the same bandwidth at the same time. Transceivers have several antennas. “It is as if several people are communicating with several other people”, explains Helmut Bölcskei, professor at the Communications Technology Laboratory at ETH Zurich. “At face value, it just seems like an incomprehensible babble. If the listeners skillfully combine the hubbub, however, they can filter out the original messages.” In terms of wireless communication, this means you can transfer far more information than with existing procedures.

Practical capability proven

ETH Zurich researchers had already furnished proof that MIMO technology works in a similar test facility three years ago – albeit with only one user. However, until recently it was still unclear as to whether and how the increase in capacity could be implemented in complex networks with several users. This is the aim of the European research pro-ject “MASCOT” (Multiple-Access Space-Time Coding Testbed), in which ETH Zurich is involved with its Communications Technology Laboratory and Integrated Systems Laboratory. It was with this in mind that the prototype developed at these two institutes was enhanced.

For the first time, the Zurich-based researchers were able to demonstrate that the principle of multiple antenna systems is actually feasible for use in complex wireless networks both theoretically and using their test facility. In doing so, they succeeded in constructing a compact multi-user system, currently with three stations in a bench scale, where every station transmits or receives via four antennae. This meant that the utilization of the frequency range for each of the three users could be up to four times higher than with present-day WLAN networks.

All set for WLAN applications

One crucial point of the research project was the development of procedures to unscramble the jumble of signals in the receiver as efficiently as possible. This presented the researchers with a problem: the more antennas and participants the system has, the more data that can in principle be transmitted; however, this also means that its demodulation is all the more difficult. As the antennas are meant to be installed in inexpensively manufactured equipment, the signals have to be decoded with as inexpensive a chip as possible, i.e. a small one. The smaller the chip, however, the smaller its computational power.

Thanks to a deeper understanding of the theoretical principles of multi-antenna systems, the researchers were able to develop efficient decoding algorithms that require a much smaller chip area. The receivers developed at ETH Zurich are currently so efficient that the new MIMO technology can easily be installed in commercially available laptops and WLAN stations.

It may be some time before MIMO technology is used in cellular phones as the antennas on hand to date require a certain distance for reliable data transfer. Consequently, the antennas have to be improved first.

MIMO-Testbed
ETH Zurich researchers used the real-time demonstrator of a MIMO WLAN network to test the practicality of their theoretical algorithms under real conditions. The test envi-ronment currently consists of 3 stations, each equipped with four antennas to transmit or receive. This enables the overall data rate of 54 Mbps (megabits per second) in modern WLAN systems to be increased to up to 216 Mbps with only one antenna for each station.

Roman Klingler | alfa
Further information:
http://www.ethz.ch

More articles from Information Technology:

nachricht World first: 'Storing lightning inside thunder'
18.09.2017 | University of Sydney

nachricht New software turns mobile-phone accessory into breathing monitor
14.09.2017 | The Optical Society

All articles from Information Technology >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

Im Focus: Fast, convenient & standardized: New lab innovation for automated tissue engineering & drug

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems Holding GmbH about commercial use of a multi-well tissue plate for automated and reliable tissue engineering & drug testing.

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems...

Im Focus: Silencing bacteria

HZI researchers pave the way for new agents that render hospital pathogens mute

Pathogenic bacteria are becoming resistant to common antibiotics to an ever increasing degree. One of the most difficult germs is Pseudomonas aeruginosa, a...

Im Focus: Artificial Enzymes for Hydrogen Conversion

Scientists from the MPI for Chemical Energy Conversion report in the first issue of the new journal JOULE.

Cell Press has just released the first issue of Joule, a new journal dedicated to sustainable energy research. In this issue James Birrell, Olaf Rüdiger,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

New quantum phenomena in graphene superlattices

19.09.2017 | Physics and Astronomy

A simple additive to improve film quality

19.09.2017 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>