Normalized Frequency
in [DSP]
|
Prev: Last Call for Papers Reminder (extended): The World Congress on Engineering WCE 2010
Next: CERN. If I had an access to the start-button of a rocket withnuclear war-head I would push it and I would direct it on Geneva.
From: ARod4594 on 21 Mar 2010 09:12 This is kind of a basic question but i am trying to figure out what the relation between the normalized frequency of a discrete frequency and one with zeros inserted between samples. For instance an analog signal sampled at a rate of 30 KHz, consisting of 3 sinusoid frequencies, 5.3Khz, 6.4 Khz, and 2.58 Khz. The normalized frequency would just be F/Fs (I belive)? But using the same samples and adding zeros between, what would be the new normalized frequency with the zero insertion?
From: HardySpicer on 21 Mar 2010 14:20 On Mar 22, 2:12 am, "ARod4594" <ilato88(a)n_o_s_p_a_m.yahoo.com> wrote: > This is kind of a basic question but i am trying to figure out what the > relation between the normalized frequency of a discrete frequency and one > with zeros inserted between samples. > > For instance an analog signal sampled at a rate of 30 KHz, consisting of 3 > sinusoid frequencies, 5.3Khz, 6.4 Khz, and 2.58 Khz. > > The normalized frequency would just be F/Fs (I belive)? > > But using the same samples and adding zeros between, what would be the new > normalized frequency with the zero insertion? You mean upsampled by a factor 2?
From: Tim Wescott on 21 Mar 2010 15:23 ARod4594 wrote: > This is kind of a basic question but i am trying to figure out what the > relation between the normalized frequency of a discrete frequency and one > with zeros inserted between samples. > > For instance an analog signal sampled at a rate of 30 KHz, consisting of 3 > sinusoid frequencies, 5.3Khz, 6.4 Khz, and 2.58 Khz. > > The normalized frequency would just be F/Fs (I belive)? > > But using the same samples and adding zeros between, what would be the new > normalized frequency with the zero insertion? By adding the zeros between (i.e. so that the new signal goes [x_0 0 x_1 0 x_2 0 ...]) you are upsampling (in and exceedingly crude sort of way). So your new sampling frequency is Fs = 60Hz, and you calculate your new normalized frequency from that. Not that without any follow-on filtering that's a _really bad_ way to upsample. -- Tim Wescott Control system and signal processing consulting www.wescottdesign.com
From: Jerry Avins on 21 Mar 2010 16:50
Tim Wescott wrote: ... > Not that without any follow-on filtering that's a _really bad_ way to > upsample. _Note_ that ... Jerry -- Discovery consists of seeing what everybody has seen, and thinking what nobody has thought. .. Albert Szent-Gyorgi ����������������������������������������������������������������������� |