Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Engineers from WorldSpace and Fraunhofer Institute Conduct Successful Tests in Satellite Time Divers

09.08.2000


WorldSpace and Fraunhofer IIS-A test Mobile Reception in Automobiles

ERLANGEN/WASHINGTON, D.C. (August 8, 2000) - A team of engineers from WorldSpace Corporation and the Fraunhofer Institut Integrierte Schaltungen have completed a successful test and demonstration of two techniques which together set the stage for WorldSpace receivers to operate in automobiles throughout the WorldSpace coverage area. These techniques are Time Diversity reception technology using current WorldSpace satellites and Multi-carrier Modulation (MCM) terrestrial rebroadcast technology for seamless reception in urban areas.

Time Diversity was achieved through the use of two broadcast channels from the AfriStar satellite, one channel delayed by 4.32 seconds with respect to the other. Time Diversity was used to eliminate blockages of the satellite transmission caused by obstacles such as bridges, trees and buildings that interrupt the line of sight to the satellite while in a moving vehicle. The method works by normally listening to the late channel and storing the early channel in a 4.32-second delayed memory. When a blockage occurs the receiver switches to the stored early channel in which the delayed early programme is precisely synchronized with the content of the blocked late channel, thus eliminating any blockage of the flow of programme content. The same process also works with data transmissions thus preventing the loss of any information content.

The MCM technology was demonstrated by conducting ground retransmissions of the same broadcast channels received from the satellite through three properly located terrestrial repeaters in Erlangen. The tests successfully demonstrated the efficacy of the MCM technique to allow seamless reception even in areas with heavy blockages of the direct signal path.

Taken together, these tests demonstrated the ability to receive the WorldSpace signal without any interruption through highway underpasses as well as in urban areas with tall buildings and structures. This is the first time that satellite Time Diversity and associated MCM retransmissions of the satellite signal have been demonstrated

"These tests represent an important step towards expanding our system capabilities to the full range of environments, whether portable, fixed or mobile throughout the WorldSpace coverage areas," said WorldSpace Chairman and CEO Noah Samara.

Additional tests and demonstrations are to be performed in Pretoria South Africa during September 2000 using a terrestrial single frequency network of MCM transmitters combined with Time Diversity satellite reception from the AfriStar satellite. Mobile receivers will compare the signal quality from the terrestrial and satellite broadcast channels and automatically select which signal best provides seamless reception between satellite reception areas and terrestrial reception areas.

About WorldSpace Corporation

Headquartered in Washington, DC, WorldSpace was founded in 1990 to provide direct satellite delivery of digital audio and multimedia services to the emerging markets of the world, including Africa, the Middle East, Asia, Latin America, and the Caribbean. The WorldSpace satellite network will consist of three geostationary satellites. The first two satellites, AfriStar and AsiaStar, were successfully launched October 28, 1998 and March 21, 2000 respectively. The third satellite, AmeriStar, will follow in 2001. Each satellite has three beams with each beam capable of delivering more than 40 channels of crystal clear audio and multimedia programming directly to portable receivers. Once completed, this unique global service will transmit quality information, education and entertainment programming to a service area that includes 4.6 billion people. For more information, visit our web site at www.worldspace.com.

About Fraunhofer IIS-A

Fraunhofer Institute for Integrated Circuits, Applied Electronics IIS-A is one of the largest R&D institutions worldwide dealing with digital broadcasting systems and audio compression technologies. About 120 scientists out of 350 employees are working in these business fields. The institute has its headquarters in Erlangen, Germany.

From the beginning, Fraunhofer IIS-A was involved in the development of the WorldSpace system including system definition and commercial uplink equipment. Fraunhofer IIS-A has also brought in its MPEG-2 Layer 3 (MP3), the audio coding standard used in the Internet. For more information, visit our web site at www.iis.fhg.de/dab

Weitere Informationen finden Sie im WWW:

Elvira Gerhäuser |

More articles from Information Technology:

nachricht Fraunhofer Radio Technology becomes part of the worldwide Telecom Infra Project (TIP)
14.11.2019 | Fraunhofer-Institut für Angewandte Informationstechnik FIT

nachricht No more traffic blues for information transfer: decongesting wireless channels
11.11.2019 | Tokyo University of Science

All articles from Information Technology >>>

The most recent press releases about innovation >>>

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

Im Focus: New opportunities in additive manufacturing presented

Fraunhofer IFAM Dresden demonstrates manufacturing of copper components

The Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM in Dresden has succeeded in using Selective Electron Beam Melting (SEBM) to...

Im Focus: New Pitt research finds carbon nanotubes show a love/hate relationship with water

Carbon nanotubes (CNTs) are valuable for a wide variety of applications. Made of graphene sheets rolled into tubes 10,000 times smaller than a human hair, CNTs have an exceptional strength-to-mass ratio and excellent thermal and electrical properties. These features make them ideal for a range of applications, including supercapacitors, interconnects, adhesives, particle trapping and structural color.

New research reveals even more potential for CNTs: as a coating, they can both repel and hold water in place, a useful property for applications like printing,...

Im Focus: Magnets for the second dimension

If you've ever tried to put several really strong, small cube magnets right next to each other on a magnetic board, you'll know that you just can't do it. What happens is that the magnets always arrange themselves in a column sticking out vertically from the magnetic board. Moreover, it's almost impossible to join several rows of these magnets together to form a flat surface. That's because magnets are dipolar. Equal poles repel each other, with the north pole of one magnet always attaching itself to the south pole of another and vice versa. This explains why they form a column with all the magnets aligned the same way.

Now, scientists at ETH Zurich have managed to create magnetic building blocks in the shape of cubes that - for the first time ever - can be joined together to...

Im Focus: A new quantum data classification protocol brings us nearer to a future 'quantum internet'

The algorithm represents a first step in the automated learning of quantum information networks

Quantum-based communication and computation technologies promise unprecedented applications, such as unconditionally secure communications, ultra-precise...

Im Focus: Distorted Atoms

In two experiments performed at the free-electron laser FLASH in Hamburg a cooperation led by physicists from the Heidelberg Max Planck Institute for Nuclear physics (MPIK) demonstrated strongly-driven nonlinear interaction of ultrashort extreme-ultraviolet (XUV) laser pulses with atoms and ions. The powerful excitation of an electron pair in helium was found to compete with the ultrafast decay, which temporarily may even lead to population inversion. Resonant transitions in doubly charged neon ions were shifted in energy, and observed by XUV-XUV pump-probe transient absorption spectroscopy.

An international team led by physicists from the MPIK reports on new results for efficient two-electron excitations in helium driven by strong and ultrashort...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

High entropy alloys for hot turbines and tireless metal-forming presses

05.11.2019 | Event News

Smart lasers open up new applications and are the “tool of choice” in digitalization

30.10.2019 | Event News

International Symposium on Functional Materials for Electrolysis, Fuel Cells and Metal-Air Batteries

02.10.2019 | Event News

 
Latest News

Theoretical tubulanes inspire ultrahard polymers

14.11.2019 | Materials Sciences

Can 'smart toilets' be the next health data wellspring?

14.11.2019 | Health and Medicine

New spin directions in pyrite an encouraging sign for future spintronics

14.11.2019 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>