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Digital
Broadcasting Networks
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Digital
Satellite Broadcasting Systems
PDR(Preliminary Design Review)of the broadcasting satellite BSAT-2 |
| SFN
(Single Frequency Network),
which enables efficient
frequency use, has become
a topic that relates to
the approaching scheduled
introduction of digital
terrestrial television broadcasting.
Our group has been promoting
research and development
of an SFN broadcasting signal
relay system which is superior
to other options in respect
of economic efficiency.
The broadcasting signal relay system is widely used on present terrestrial analog broadcasts. However, SFN still has a technical problem, which consists of signal circulation between transmission and reception antennas located at the same relay station. This circulation interferes with the same incoming main station frequency signals and results in a deterioration of transmission radio waves. We are developing a technology which combines high-speed signal processing to cancel complicated fluctuations in the circulating signals and a specification improvement of the antenna. This technology can be widely applied to present relay stations as it is developed. |
Digital
satellite broadcasting is
starting in December, 2000,
using the new broadcasting
satellite BSAT-2. (BSAT
Corporation) has been promoting
the preparation of a satellite
for digital satellite broadcasting,
and NHK has contributed
its technical support. The
NHK Science & Technical
Research Laboratories have
been cooperating from the
planning stages, especially
in regard to the broadcasting
satellite relay systems.
In the autumn of 1998, it was decided to place the order for BSAT-2 with the US Orbital Science Corporation, and basic engineering for the whole satellite system is now underway. A representative from the Laboratories also attended the PDR (preliminary design review) conference which was held in the United States in March last year. The scheduled launch of BSAT-2 is the autumn of 2000, after passing the CDR (critical design review) process, 1999 and also an I&T. |
|
 Kiyoshi
MURAKAMI, Director, Digital Broadcasting Networks Division |
 Junji
KUMADA, Director, Digital Satellite Broadcasting Systems Division |