Signals & Systems

A signal is what you want and the noise is what you don't want and the signal to noise ratio (S/N) is ALWAYS the issue.

1. Time and voltage. (OR time and modulation, if you prefer).

"Brendan Gillatt" wrote in message news: snipped-for-privacy@pipex.net...

Does not matter. A signal is what you want. Noise is what you don't want. Sorting them out is the challenge.

Niall 84 hath wroth:

Please re-read your instructions. You're suppose to *FIND* the answers to your questions. That means reading everything you can find on the topic and get a good understanding of what is involved. If you just ask the experts for the answers, you've learned nothing.

I look at it a bit differently. If you don't understand the question sufficiently to rephrase the questions properly, then you don't know anything about the topic. Some reading would be helpful.

Sure they can. Would you like them to also do your homework for you? Perhaps after they graduate you, would you like someone to "give" you a job and then have us do the work for you? It's a long slipper slope that hopefully can be stopped right now while you're in skool. Do your own work. You won't regret the effort.

My signals are informal. I usually just wave or elevate one finger. The last formal signal I did was a 21 gun salute (which incidentally had to be done with only 6 of the rifles loaded with blanks because of a local noise ordinances).

Perhaps you might consider getting a bit more concrete? The way you're phrasing your questions implies that you don't have the necessary vocabulary, which you will obtain only by doing some reading.

Zero. My tape measure can't seem to find a TV signal to measure. Incidentally, television is not abreviated as T.V.

Split the difference and try 2.5 for the assignment.

Wait a few years, when you are put in a position where there's nobody that can do your homework for you, then you'll thank me for suggesting that you do your own work.

Hey everyone,

Thanks a million for the help.

Niall

Actually, sometimes the noise IS what you want... For example, I've seen some two-way radio squelch systems that "detect" excessive noise above 10kHz in audio circuits to do funky things with encoding and speech compression, etc...

Of course in that case, I guess you could argue the noise "is" the signal.

Also, I vaguely remember some applications that would sample noise and adjust audio output to meet environmental listening requirements. I think DBX has some gear like this...

It is any "message." A signal is something that either carries or is information. (But strictly, a carrier medium is not quite a signal in my lingo, as it must be decoded into something directly sensed by humans to be a signal. That means the five senses. However, most folks will say a baseband electrical "wave" is a signal. I would say the baseband wave energy is still information carried in the electro- magnetic domain, although I adhere to conventional language and don't press it. Most people do not in language distinguish between a signal laden carrier and the signal itself. They just call it all "the signal.") If any aspect of the message/information is new to the receiver, then the message has entropy. A signal with only information that was already known did not need to be sent.

A smoke signal is a message/signal. Any thing that gives you information you did not previously have (the "thing" has entropy), can be considered a signal.

A TV screen is perhaps obviously 2-d, as is the original recording.

It ain't no hologram.

Is wine a carrier or the signal itself?

Niall 84 wrote in news:1191275000.742833.63830@

IMO, them means information communicated through a medium.

The details depends what the information is, and what the medium is.

I agree with the latter, but completing the circle, I believe "signal" must be defined by it's application, which depends on the user's intentions.

No single answer can answer the question of what is a signal.

Here ya go!

Hope This Helps! Rich

One of the problems in technical communication is that often the author/speaker assumes that the reader/listener has the same definition for a word. This comes up ALL the time, and often when it should but doesn't, it's the source of a lot of confusion. About the best answer I know is to include a section in papers you write that defines your terms. So, if you find lots of differing definitions of "signal," and it matters to you that you communicate clearly, pick a reasonable definition and state it. Perhaps acknowledge that other definitions exist and may be perfectly valid in other contexts.

It can also help to use a good technical dictionary. There's an IEE dictionary that may have multiple definitions of "signal."

I can't speak for YOUR instructor, but if I were to have made that assignment, I'd be quite happy if you told me that there are multiple definitions, and that you'd learned the importance of making sure your audience shares the definition you're working with.

Notice that the number of dimensions of a TV signal is covered in about the same way. What, exactly, is your definition of "dimension" in that case? It probably depends on just what aspect of the TV "signal" you are talking about: propagation, encoding/decoding, amplification, ...

Cheers, Tom

Tom Bruhns snipped-for-privacy@msn.com posted to sci.electronics.design:

Indeed, if i wanted to get into the formal definitions of how to assemble a "TV" signal i could probably come up with 12 or more dimensions without trying. (pun intended)

Well, if you intended a pun, it's gone right over my head. Would you please be so kind as to enlighten this iggorant Jack-pine savage which pun you intended? I'd like to laugh or groan along with the more erudite.

Thanks, Rich

Rich Grise snipped-for-privacy@example.net posted to sci.electronics.design:

i was abusing the the concept difference between spatial dimensions and drawing dimensions. Didn't mean to confuse.