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Article #196

Re: Using an FM-Carrier for the Y [Luminance] Signal -- how to relieve the bandwidth issue?

#196
From: Green Xenon [Radium]
Date: Thu, 01 Nov 2007 06:08
144 lines
8873 bytes
Bob Myers wrote:

> "Green Xenon [Radium]" <glucegen1@excite.com> wrote in message 
> news:4727a189$0$19640$4c368faf@roadrunner.com...


> 
> 
>>I'd like my QAM video signal to be at least 1-billion-bits-per-symbol but 
>>no more than 1-symbol-per-second. I then want to transmit this video 
>>signal on an ULF FM radio signal whose carrier wave is only 300 Hz.


> 
> 
> I realize you're again just either trolling or so astoundingly ignorant of
> the field that it's amazing you're walking around without a keeper, 
> but...why?
 >
> What possible advantage would such a system have, if it were possible
> in the first place (which it isn't, not by a rather large number of orders
> of magnitude)?

Okay I got a bit carried away here. Sorry. 1-billion-bits-per-symbol is 
equivalent allows for 2^1,000,000,000 voltages. This is not possible. 
Just an imagination. Please forgive me and forget about it.

Anyways, the QAM should be given the highest practical bit-resolution. 
1-symbol-per-second should be the baud.

The following is interesting but only theoretically-possible. Not gonna 
happen with today's technology:

The minimum voltage should be set to 1.6e-19 volt. This is the voltage 
of one electron. The maximum voltage should be set to the highest you 
can get *without* doing any of the following to any extent:

1. Exceeding the dielectric strength of any electronic component

2. Generating temperatures above 70 Fahrenheit in any electronic component

3. Ionizing any electronic component

The bit-resolution should be high enough that each "level" is a 
difference of 1.6e-19 volt from the level above/below. A resolution of 
8-bit allows for only 256 different levels -- obviously *way* too low.


> 
> And what in the hell does "QAM video signal" on an "FM radio signal"
> mean in the first place?
> 

Again, the following is interesting but only theoretically-possible. Not 
gonna happen with today's technology:

The original Y signal is converted to QAM. This QAM signal is then 
broadcasted on an FM radio carrier wave whose base frequency is 300 Hz. 
300 Hz is the lowest ULF frequency and the lowest frequency used by 
telephones.

http://en.wikipedia.org/wiki/Ultra_low_frequency

Prior to converting the Y signal to QAM, the temporal and spatial 
frequencies [excluding DC -- 0 hertz] are downshifted in real time [sort 
of like the video-equivalent of the voice-changers used on the phone 
which can decrease the pitch of your voice in real time without 
decreasing the speed of your speech]. This frequency downshifting does 
not involve decreasing the "speeds" of the temporal or spatial 
components of the Y-signal. All temporal and spatial frequencies other 
than zero-hertz are shifted closer to zero. This decreases the bandwidth 
of the Y-signal. No low-pass filtering. No changing the speed of the 
temporal signal. No changing the size of the spatial signal.

Even though the spatial signal does not have "speed" as its component 
because it is -- by nature -- static, it does have an equivalent which I 
have a hard time figuring out. Perhaps it�s the size? Decreasing the 
"speed" might involve increasing the size of the image? I am guessing 
this is the case.

There are many audio softwares that allow downshifting the frequencies 
of music until they are closer to zero. They can do this without slowing 
the playback speed or increasing the length of the song. If a frequency 
is zero Hz, its stays at zero. However, if a frequency is not zero, it 
is shifted closer to zero.

Apparently -- from what I see on the graph my audio software [Adobe 
Audition 1.5] -- downshifting decreases the amount of cycles per 
distance and then increases the lengths of the waves. So basically the 
signal does not take up more space than it did prior to the 
pitch-shifting. The amount of waves per area decreases but the remaining 
waves are increased in length, so the distance from where the waves 
started to where they finish do not decrease -- their lengths increase 
but their amounts decrease. So overall, the distance from start to 
finish remains the same. Hence the file�s length does not change.

The real-time-video-equivalent of the above is done to decrease the 
overall frequency [and bandwidth] of the Y-signal prior to converting it 
to QAM. A sufficient amount of this frequency-downshifting is done to 
the original Y-signal such that the resulting QAM signal does not cause 
the FM signal to develop sidebands beyond 301 Hz or 299 Hz -- sideband 
is only 1 Hz + or - from baseband.

Equally important, prior to conversion to QAM, the amplitude levels of 
the Y-signal are brought closer to the neutral without decreasing the 
amount of levels -- darker than neutral result is represented by a 
negative electric current while brighter than neutral is represented as 
a positive electric current. When the Y-signal is at medium light 
intensity, the current is neutral [i.e. right on the x-axis of a graph 
when measured]. Anyways, all of the brightness levels are shifted 
towards the x-axis so that the resulting QAM signal will not cause the 
FM radio signal's frequency to deviate beyond 301 Hz or 299 Hz -- peak 
deviation is only 1 Hz + or - from baseband.

In a luminance signal, the medium light intensity is represented by 
voltages that are neither positive nor negative. If the light intensity 
increases above the medium brightness, a positive voltage results. If 
the light intensity falls below medium brightness, a negative voltage 
results. This is because the Y-signal is represented by AC current.

The chroma along with instructions regarding how to reverse-process the 
Y-signal [so the original Y-signal is retrieved] -- as well as properly 
linking the chroma with the luma -- is delivered from the transmitting 
end to the receiving end via optic fibers. That way the equipment 
receiving the FM video signal can best decode the video back to how it 
originally looked -- not exactly how it looked but close.

One potential disadvantage of this tech is the white flashes on the 
receiver's screen when there are electrical storms in the atmosphere 
[such as lightning], or manmade electric disturbances such as florescent 
lamps and automobile ignitions. Such visual interferences are worse 
during cloudy/rainy weather -- even if there is no lightning. The 
reception maybe FM, but the receiver is built to be extremely sensitive 
to the extremely low power signals emitted from the transmitting end.

This FM receiver can coherently receive frequency-modulated 300 Hz 
electromagnetic signals as weak as 1.3e-24 watts per
square meter. This weak signal is equivalent to 1 photon per second per 
square meter.

Turn on a distant xenon-lamp [on the otherside of the world] and boom! 
The monitor displaying the video signals will start to show some 
interesting white disruptions -- dancing zig-zag lines, sawtooth waves, 
etc. That�s how sensitive this receiver is.
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Date: Wed, 31 Oct 2007 22:08:07 -0800
From: "Green Xenon [Radium]" <glucegen1@excite.com>
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Newsgroups: uk.tech.digital-tv,uk.tech.broadcast,sci.electronics.misc,ba.broadcast,alt.radio.broadcasting
Subject: Re: Using an FM-Carrier for the Y [Luminance] Signal -- how to relieve
 the bandwidth issue?
References: <46fc71d2$0$24285$4c368faf@roadrunner.com>   <u9hus4-6vi.ln1@radagast.org>   <4722f832$0$25703$4c368faf@roadrunner.com>   <ujr6i3dolk1qjon2ij5tta8aip26tff9qa@4ax.com>   <slrnfi6tb4.n9a.pm@thinkpad.nowster.org.uk>   <4723dde6$0$19659$4c368faf@roadrunner.com>   <1193758919.924634.276450@y27g2000pre.googlegroups.com>   <5op40sFnr30mU1@mid.individual.net> <1193769738.441836.79230@k35g2000prh.googlegroups.com> <lISdnTog1rjMCrranZ2dnUVZ8vydnZ2d@pipex.net> <4727a189$0$19640$4c368faf@roadrunner.com> <fgb5ae$6da$1@usenet01.boi.hp.com>
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