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Article #147Re: Using an FM-Carrier for the Y [Luminance] Signal -- how to relieve the bandwidth issue?
From: Green Xenon [Radium]
Date: Sun, 30 Sep 2007 05:34
Date: Sun, 30 Sep 2007 05:34
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On Sep 29, 8:59 pm, dpl...@radagast.org (Dave Platt) wrote in http://groups.google.com/group/uk.tech.digital-tv/msg/872fdf9b0c765bd0 : > In article <46fefb70$0$7493$4c368...@roadrunner.com>, > Green Xenon [Radium] <gluceg...@excite.com> wrote: > > > > Sure it is possible. It won't be of any assistance to you (or to > > > anyone else since you can't put 8 pounds in a 1-pound sack. > > > Bandwidth is bandwidth, no matter how you slice it. Do you > > > really think that nobody has thought of various methods of > > > transmitting video over low-bandwidth paths? If so, you need > > > to study not only science and engineering but the HISTORY > > > of science and engineering. > > >There are 8-bits-per-symbol, only 1 baud. The symbol is split into 8 > >parts. Each part is 1-bit. > > >How is this �putting 8 pounds in a 1-pound sack?� > > >It�s more like �putting 1 pound in a 1-pound sack� > > You are using the word "split" without defining what you are meaning, > and I think you may be using the word "bit" in two different ways (as > in "a single binary digit's worth of information" and "a part")... > maybe I'm wrong about the latter. > > Sure, you can carry 8 bits of information per symbol, at a rate of one > baud. That's an information rate of 8 bits per second, which isn't a > terribly useful amount of information. > > What I *think* you are saying is something along the lines of > > "If there's no way to carry N bits of information per symbol (where > N is a large number) at a rate of 1 symbol per second, in a > specified bandwidth, over a channel having a certain amount of > dynamic range / signal-to-noise ratio available, then I'd > like to somehow divide each symbol into eight sub-symbols which > each carry N/8 of the information, but which still make up only one > symbol per second. My hope is that these eight sub-symbols could > be easier to transmit, somehow, than a single symbol carrying N > bits, and that I could thus transmit them more easily but without > using any more bandwidth. Can I do that?" > > If that's what you're asking, the answer is "no". > > Once you hit the theoretical information limit of the communication > channel (which is set by the bandwidth you use and by the amount of > noise on the channel) you can't do any better than that. No matter > how you modulate (changing the baud rate, the amount of information > per symbol, etc.) you can't do better than this. > > And, as we've been trying to make clear, your goal is quite far beyond > the theoretical limit. You just can't get there. You're trying to > put all of Lake Erie in a water-glass. > > Let it go, Radium. Within physical-possibility, what is the largest amount of bits-per-symbol [assuming a baud-rate of only 1-bit-per-symbol] that can be reached without the highest-voltage causing any clipping, generating any temperatures above 70 Fahrenheit, resulting in any harm to anyone/anything [including the equipment itself], or shortening the life of the equipment and without the lowest-voltage being lost in the noise? What is the maximum-possible amount of discrete levels between the highest and lowest voltage in such a signal? An 8-bit signal can have a maximum of 256 different voltage levels between the highest and lowest voltage. Right? Go too high and the signal clips, go too low and the signal will not be recognized.
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X-Google-Thread: f928c,9d8320c16fbdcf84 X-Google-Thread: 1133a5,9d8320c16fbdcf84 X-Google-Thread: 115947,9d8320c16fbdcf84 X-Google-Thread: 1118be,9d8320c16fbdcf84 X-Google-Thread: ffcae,9d8320c16fbdcf84 X-Google-Thread: 107cee,9d8320c16fbdcf84 X-Google-Thread: f508e,9d8320c16fbdcf84 X-Google-Thread: f7d8a,9d8320c16fbdcf84 X-Google-Thread: fdad6,9d8320c16fbdcf84 X-Google-Attributes: gidf928c,gid1133a5,gid115947,gid1118be,gidffcae,gid107cee,gidf508e,gidf7d8a,gidfdad6,public,usenet X-Google-Language: ENGLISH,CP1252 Path: arc1-ca.pugleaf.net!g2news2.google.com!news1.google.com!border1.nntp.dca.giganews.com!nntp.giganews.com!nx01.iad01.newshosting.com!newshosting.com!post02.iad01!roadrunner.com!not-for-mail Date: Sat, 29 Sep 2007 22:34:17 -0700 From: "Green Xenon [Radium]" <glucegen1@excite.com> User-Agent: Mozilla/5.0 (Windows; U; Win98; en-US; rv:1.8b) Gecko/20050217 MIME-Version: 1.0 Newsgroups: uk.tech.digital-tv,rec.video.production,uk.media.tv.misc,sci.electronics.components,uk.tech.broadcast,sci.electronics.misc,aus.radio.broadcast,ba.broadcast,alt.radio.broadcasting Subject: Re: Using an FM-Carrier for the Y [Luminance] Signal -- how to relieve the bandwidth issue? Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 8bit Lines: 69 Message-ID: <46ff32e0$0$32538$4c368faf@roadrunner.com> Organization: Road Runner High Speed Online http://www.rr.com NNTP-Posting-Host: 75.84.20.87 X-Complaints-To: abuse@rr.com