[opendtv] Re: (No Date: Tue, 28 Sep 2004 10:30:37 -0400

From: "Manfredi, Albert E" <albert.e.manfredi@xxxxxxxxxx>
To: "OpenDTV (E-mail)" <opendtv@xxxxxxxxxxxxx>
Date: Thu, 14 Oct 2004 18:26:13 -0400

Barry Wilkins wrote:

> Why wasn't there an effort to ditch the ATSC modulation
> at the earliest opportunity if (a) the revenue was
> likely to go overseas, and (b) there were strong
> indications of performance limitations and (c) there
> was an opportunity to use a US version of COFDM that you
> could get patent royalties from?

There were efforts to ditch 8-VSB, and the FCC in 2001
I think it was, wrote a report in which they determined
that since progress was being made with 8-VSB receivers,
it would stay the course. The report also compared
the performance of the two systems.

But there were many announcements even before the
final decision.

For example, way back in 1999:

-------------------------
http://ftp.fcc.gov/Bureaus/Engineering_Technology/News_Releases/1999/nret=
9004.doc

[ ... ]

Most of the industry representatives stated that, in
theory, 8-VSB and COFDM should be able to perform nearly
the same where there is static multipath.  Most also
stated that COFDM can generally be expected to perform
better in situations where there is dynamic multipath,
e.g., in mobile operations.

A number of parties also stated that 8-VSB offers a
number of advantages over COFDM for broadcast DTV
service, including superior overall coverage, lower
costs of construction and operation, and immunity to
impulse noise from household appliances.  Industry
representatives also asserted that 8-VSB receivers that
perform better than the units used in the demonstration
are, in fact, available now.  The consumer electronics
(CE) manufacturers all viewed multipath performance as
an issue that will be worked out in the normal process
of improving new products.

The study found that each system has its unique
advantages and disadvantages.  The 8-VSB system, in
general, has better threshold or carrier-to-noise (C/N)
performance, has a higher data rate capability,
requires less transmitter power for equivalent
coverage, and is more robust to impulse and phase
noise.  The COFDM system, on the other hand, has better
performance in dynamic and high level static multipath
situations, and offers advantages for single frequency
networks and mobile reception.

[ ... ]
--------------------------

For my part, when I saw the results of Chinese
broadcasting in Hing Kong, where 8-VSB did just fine
thanks you, both indoor and outdoors, I started
wondering. That was in 2000.

Then, in April of 2002, the Canadian Research Council
published lab test results of the Linx 4th gen
prototype. At which point, it seemed perhaps the FCC
had made a reasonable decision.

Linx then did field tests which seemed to confirm
the results. And then came LG and their 5th gen. And
I'm sure it won't stop there.

Bert

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[opendtv] Re: (No Date: Tue, 28 Sep 2004 10:30:37 -0400

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