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Adaptive Modulation System

  1. Mar 19, 2015 #1
    1. The problem statement, all variables and given/known data
    upload_2015-3-19_19-15-1.png

    2. Relevant equations

    upload_2015-3-19_19-13-57.png



    3. The attempt at a solution

    I can't figure out how to get those numbers, I think I have to convert from dB when actually calculating it but I'm unable to get those ones.

    I have
    PQPSK = 0.502368
    P16QAM = 0.0526855
    P64QAM = 0.000004
    Pno = 0.4450
     
  2. jcsd
  3. Mar 25, 2015 #2
    Thanks for the post! This is an automated courtesy bump. Sorry you aren't generating responses at the moment. Do you have any further information, come to any new conclusions or is it possible to reword the post?
     
  4. Mar 26, 2015 #3
    I figured it out,
    upload_2015-3-26_18-26-20.png
    Those are not in dB, even though I thought they were. So I was converting everything from dB or nothing from dB

    so the integral ends up being -exp(gamma/gamma_bar) evaluated from a to b.

    -exp(-52.98/ ( 10^(18/10) )) + exp(-10.6/ ( 10^(18/10) )) = 0.413505

    -exp(-222.53/ ( 10^(18/10) )) + exp(-52.98/ ( 10^(18/10) )) = 0.402453

    + exp(-222.53/ ( 10^(18/10) )) = 0.0293970
     
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