- dt is the sampling time (in seconds per sample)
- Fs is the sampling rate (in samples per second)
- Fnyq is the Nyquist frequency (in hertz)
- Fco is the cutoff frequency (in hertz)
- bw = bandwidth (in hertz)
- Fc is not needed to compute wn
filter
2 views (last 30 days)
Show older comments
in butter(1,wn) i know wn is normal frequency =(cut off/nyq.freq) in amplitude modulation what will be wn=? if carrier freq=fc and i calulat 0:.001:1 sample and message freq fm
0 Comments
Accepted Answer
Rick Rosson
on 6 Jan 2012
Code:
dt = 0.001; % sampling time (seconds per sample)
Fs = 1/dt; % sampling rate (samples per second)
Fnyq = Fs/2; % Nyquist frequency (hertz)
Fco = fm + bw; % Cut-off frequency (hertz)
wn = Fco/Fnyq; % Normalized cut-off (dimensionless)
Explanation:
You should make sure that the following conditions are true:
bw << fm << fc
and
bw << fm << Fs
HTH.
Rick
More Answers (1)
Rick Rosson
on 5 Jan 2012
Please try:
dt = 0.001;
Fs = 1/dt;
Fnyq = Fs/2;
Fco = fm + bw;
wn = Fco/Fnyq;
HTH.
6 Comments
Rick Rosson
on 6 Jan 2012
The idea of bandwidth is that the message has a spectrum that extends across a range of frequencies centered at f = fm. You can assume that the range is [ fm-bw ... fm+bw ].
Rick Rosson
on 6 Jan 2012
You should also make sure that the following conditions are true:
bw << fm
and
fm << fc
See Also
Categories
Find more on Get Started with Signal Processing Toolbox in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!