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Posted by Green Xenon [Radium] on 09/26/07 18:28
On Sep 25, 1:36 pm, "Brian Gregory [UK]" <n...@bgdsv.co.uk> wrote in
http://groups.google.com/group/uk.tech.digital-tv/msg/e85e65d92a479a00 :
> "Green Xenon [Radium]" <gluceg...@excite.com> wrote in
messagenews:46f86fa7$0$9596$4c368faf@roadrunner.com...
>
> > Couldn’t the video signal first be
> > converted to QAM, multiple-level
> > quadrature modulation, and/or
> > constellation modulation and then
> > transmitted on a FM radio carrier?
>
> > AFAIK, the
> > QAM/multiple-level-QM/constellation-modulation
> > version of the
> > video signal won’t require as much
> > bandwidth as the original video signal.
> > The original video signal is first converted
> > to bits and symbols and then
> > transmitted on an FM radio carrier.
> > To make the best use of bandwidth,
> > limit the baud to only
> > 1-symbol-per-second but pack as many
> > bits-per-symbol as feasible.
> Why?????
>
> Why make it use more bandwidth by
> introducing totally superfluous FM
> modulation??
I wish I could answer that question. It’s a matter of personal
preference. I’ve got this urge to get what I know I can’t have. FM video
is one of them. Hence, I want to do anything possible to transmit the
luminance component of video signals on FM without hogging excessive
bandwidth.
QAM/multiple-level-QM/constellation-modulation are examples of exotic
modulation techniques that allow you to transmit/receive the most amount
of information while using the least amount of bandwidth. To further
prevent excessive usage of bandwidth while maintaining signal
efficiency, the baud should be no more than 1-symbol-per-second while
the amounts of bits-per-symbol conveyed should be the most that is
physically and mathematically-possible.
Before being transmitted on the FM carrier, the luminance video signal
should be converted to QAM, multiple-level-QM, and/or
constellation-modulation. The
QAM/multiple-level-QM/constellation-modulation version of the video
signal won’t consume as much FM bandwidth as the original video signal.
If the original luma is transmitted on an FM carrier, the resulting
deviations in the frequency of the FM wave will be excessive. If the
QAM/multiple-level-QM/constellation-modulation equivalent of the luma is
transmitted, the resulting frequency-deviations will be significantly
smaller and hence use a lot less bandwidth.
I’ve got a neurological disorder which I would like to discuss briefly.
I am not trying to make excuses for any of my posts but I don’t want
readers to wrongly-assume that I troll/spam NGs just for attention. I am
really interested in the stuff I post about and wish that the readers
would not get upset at me.
I have a neurological disability called Asperger's Syndrome.
I would like to give you all some information about my disability. The
reason I am posting this message about Asperger's is to help avoid any
potential misunderstandings [though it's probably too late].
I have been diagnosed with Asperger's Syndrome (AS). AS is a
neurological condition that causes significant impairment in social
interactions. People with AS see the world differently and this can
often bring them in conflict with conventional ways of thinking. They
have difficulty in reading body language, and interpreting subtle cues.
In my situation, I have significant difficulty with natural
conversation, reading social cues, and maintaining eye contact. This can
lead to a great deal of misunderstanding about my intent or my behavior.
For example, I may not always know what to say in social situations, so
I may look away or may not say anything. I also may not always respond
quickly when asked direct questions, but if given time I am able express
my ideas.
On Usenet, the cyber-equivalent of my disability is probably noticed. I
do apologize profusely, for any inconvenience it causes.
Thank you very much in advance for your understanding, cooperation, and
assistance.
Regards,
Radium
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