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Modulation and signals

  1. Jan 28, 2006 #1
    Hi do u have any good articles about signals and modulation...
    I want to know why we use modulation and how the world would be if no modulation was used at all...
    Waht arre the types of modulation?
    What are the differences between them?
    What are the adgvantages and disadvantages for each of them?
  2. jcsd
  3. Jan 29, 2006 #2
    This sort of sounds like homework.

    Amplitude Modulation (AM), Frequency Modulation (FM), and Phase Modulation (PM) are a few types of modulation. Look these up on the internet (use google) and you'll find the answers you need.
  4. Jan 29, 2006 #3


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    Yep, google is a great tool. I googled modulation communication theory, and got lots of good hits. This one from wikipedia was one of the first ones, and looks pretty helpful:

  5. Jan 29, 2006 #4


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    Yeah this sounds an awful lot like homework but let me just ask you if a signal is not modulated in any way, in other words it simply exists as a steady state, what information is it conveying? Does that give you an idea of what the world would be like with nothing modulated?
  6. Jan 29, 2006 #5


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    The signal would convey no communication information except the amplitude and frequency of the carrier signal, which is typically a radio frequency (RF), but could be any sinusoidal wave in the electromagnetic spectrum.
  7. Jan 29, 2006 #6


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    :rolleyes: It was a rhetorical question meant for the OP. I already knew the answer.
  8. Feb 11, 2006 #7
    Ok thx but we can use the signals ups and down to represent 1 and 0 accordingly....
    If we modulate a signal what kind of information it conveys
  9. Feb 11, 2006 #8


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    What you just described IS modulating the signal.
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