| Author |
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Gunstinger
Guest
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 Posted:
Tue Dec 13, 2005 5:16 pm Post subject:
FSK mod and demod |
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Hello I'm stuck with a little problem here in MatLab. What I need to do i
input a string of text, convert it to binary, and then use FSK to mod i
together, then demod and and filter it out and convert it back to tex
again. The first part is easy, the input of text and converting, what i'
having trouble with is using FSK to put the binary input and the carrie
waves together to get my modulated signal. Here's the code I have so far.
phrase = input('Enter desired word or phrase: ','s')
binphr=dec2bin(abs(phrase))
fs=8000
tn = 0:1/fs:0.005;
phi2 = 360;
xx = [cos(2*pi*1650*tn), cos(2*pi*1850*tn + phi2)];
So I have my binphr and xx, so how do I combine the two. |
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Mike Yarwood
Guest
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| Posted:
Tue Dec 13, 2005 5:16 pm Post subject:
Re: FSK mod and demod |
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"Jerry Avins" <jya@ieee.org> wrote in message
news:idadnbArCbyUbQPenZ2dnUVZ_tCdnZ2d@rcn.net...
| Quote: | Gunstinger wrote:
Hello I'm stuck with a little problem here in MatLab. What I need to do
is
input a string of text, convert it to binary, and then use FSK to mod it
together, then demod and and filter it out and convert it back to text
again. The first part is easy, the input of text and converting, what i'm
having trouble with is using FSK to put the binary input and the carrier
waves together to get my modulated signal. Here's the code I have so far.
phrase = input('Enter desired word or phrase: ','s')
binphr=dec2bin(abs(phrase))
fs=8000
tn = 0:1/fs:0.005;
phi2 = 360;
xx = [cos(2*pi*1650*tn), cos(2*pi*1850*tn + phi2)];
So I have my binphr and xx, so how do I combine the two.
The closest meaning I can imagine for converting a string of text to
binary involves some sort of encoding, like EBCDIC or ASCII. If it isn't
already encoded, how do you input it?
FSK stands for "frequency shift keying". ("Keying" is an archaic synonym
for modulation.)
I suspect that you need to rethink your procedures.
and ask yourself whether you want your tn to be 41 samples long , and why |
you have added 360 radians to your second vector.
Best of luck - Mike |
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Jerry Avins
Guest
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| Posted:
Tue Dec 13, 2005 5:16 pm Post subject:
Re: FSK mod and demod |
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Gunstinger wrote:
| Quote: | Hello I'm stuck with a little problem here in MatLab. What I need to do is
input a string of text, convert it to binary, and then use FSK to mod it
together, then demod and and filter it out and convert it back to text
again. The first part is easy, the input of text and converting, what i'm
having trouble with is using FSK to put the binary input and the carrier
waves together to get my modulated signal. Here's the code I have so far.
phrase = input('Enter desired word or phrase: ','s')
binphr=dec2bin(abs(phrase))
fs=8000
tn = 0:1/fs:0.005;
phi2 = 360;
xx = [cos(2*pi*1650*tn), cos(2*pi*1850*tn + phi2)];
So I have my binphr and xx, so how do I combine the two.
|
The closest meaning I can imagine for converting a string of text to
binary involves some sort of encoding, like EBCDIC or ASCII. If it isn't
already encoded, how do you input it?
FSK stands for "frequency shift keying". ("Keying" is an archaic synonym
for modulation.)
I suspect that you need to rethink your procedures.
Jerry
--
Engineering is the art of making what you want from things you can get.
ŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻ |
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