[opendtv] More 1999 stuff

Here is another cached Google article by Dale Cripps.  It is facinating to 
me how far we have come in 6 years.  (NOT!)

John Shutt

**********************

I wrote the following to Mike. He was kind enough to answer below and let us 
use his response for a discussions point. It is an important response to 
keep in mind as we move further down what could be a disruptive course of 
altering the standard at the FCC.

Dear Mike,

Can you throw any light on this modulation story? Are we just in too early 
an iteration to draw a sound conclusion, or is there some fundamental reason 
why this will never get "that much" better...better, yes, but "that" much 
better to satisfy the market deeply? Any light you can shed (off or on the 
record) is very welcome.

Dale Cripps


Dale,

During the time that many research groups(including my own at Philips Labs) 
were competing outside, and then inside of Grand Alliance, to develop the 
best system - 8-VSB and COFDM were compared on a few occasions.

As I was told by the experts at that time, there fundamentally is no 
theoretical limit on performance of 8-VSB and it could be identical to 
COFDM.

Initial complexity is the issue. (The) 8-VSB allows simpler and less 
expensive implementation for reasonably good outdoor channels or CATV. 
Remember, more then 60% of Americans watch CATV these days and only 25% are 
using reception from the air. A really small minority of these 25% use 
indoor reception. Rest are probably using DBS--that is QPSK in any case.

COFDM could not be scaled for simpler implementation. It is a complex 
demodulator from start. My understanding, again from the words of some 
experts, that if you increase complexity of 8-VSB demodulator to be equal of 
the complexity of COFDM demodulator, their performance will be equal as 
well. Of course I, and probably nobody else yet, have seen that implemented 
for obvious reasons: FCC and broadcasters always specified outdoor reception 
as necessary criteria for DTV. And 8-VSB in its simpler implementation 
always beat COFDM tests in these channels.

CE industry was always aware of possible use of DTV on CATV and 8-VSB in its 
simpler implementation works fine in these channels as well. There were no 
indication then, and I do think even now, that robust indoor reception is a 
needed requirement. I think 8-VSB is a flexible enough system that if DTV 
business will demand indoor reception, more complex 8-VSB demodulators will 
be available on the market. Do broadcasters and FCC need a proof of this 
now? If they are - we (industry wide) have experienced engineers and 
laboratories who may be able to construct this kind of prototype.

In my mind the real question is how many Americans are watching TV on indoor 
antenna today and how many will continue to do so after they purchase $3000 
worth of DTV receivers and HDTV monitors tomorrow?

I hope this helps,

Mikhail Tsinberg
Senior Manager
Toshiba America Consumer Products
82 Totowa Road
Wayne, NJ, 07470
E-mail: mike@xxxxxxxxxxxx


 
 
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