1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Lowest Sampling rate

  1. Aug 24, 2016 #1
    1. The problem statement, all variables and given/known data
    In some cases, the spectrum replication property of sampling can be used as a substitute for demodulation. Given a signal xa(t) with the spectrum shown, what is the lowest sampling rate that will ensure both no aliasing of the spectrum, and that one of the spectrum replicas is centered at f = 0?

    Figure_zpsyaqlj2ks.png
    http://s716.photobucket.com/user/Pitoraq/media/Figure_zpsyaqlj2ks.png.html?sort=3&o=0
    (Note it should be 125 Hz to the right in the figure not 115 Hz)

    2. Relevant equations

    f(Nyquist fre.) = (1/2)*v(sampling freq.) (1)


    3. The attempt at a solution

    If the bandwidth is 125-95 = 30 Hz

    How can i then determine the lowest sampling rate ?

    The answer should be 35 MHz
     
    Last edited by a moderator: Aug 24, 2016
  2. jcsd
  3. Aug 24, 2016 #2

    NascentOxygen

    User Avatar

    Staff: Mentor

    Hi Firben. What have you found from your google searches?
     
  4. Aug 25, 2016 #3

    rude man

    User Avatar
    Homework Helper
    Gold Member

    f(Nyquist fre.) = (1/2)*v(sampling freq.) [/quote]
    This is not the correct formula for a passband spectrum. It would be if the original spectrum went from dc to 115 MHz (or 125 MHz) but it goes only from 95MHz to 115 or 125 MHz.
    EDIT:
    I can't resolve the correct answer (fs = 35 MHz) with any of a spectrum of 95 -115 MHz, or one of 85 -125 MHz, or one of 95 -125 MHz. I suggest you re-check the problem statement.
     
    Last edited: Aug 27, 2016
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Lowest Sampling rate
  1. Nyquist Sampling (Replies: 0)

  2. Sampling with aliasing (Replies: 6)

Loading...