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<DIV><FONT face=Arial>Tom,</FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>Brute force says fast Fourier transform (FFT). With
AM, the two signals undergo multiplication to produce a signal that can be
represented by A*sin(wc)*sin(wi). This resolves to a signal of
A*(cos(wc-wi) - cos(wc+wi))/2. </FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>Please let me know how this helps.</FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>ray</FONT></DIV>
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<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=t_sedgman@yahoo.com href="mailto:t_sedgman@yahoo.com">tom sedgman</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=users@lists.scilab.org
href="mailto:users@lists.scilab.org">users@lists.scilab.org</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Thursday, April 29, 2010 9:52
AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> [scilab-Users] Amplitude
Demodulation</DIV>
<DIV><BR></DIV>
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<TD vAlign=top>Hi again everyone,<BR><BR>I've got stuck, I'm trying to
write code to calculate the amplitude and frequency of a low frequency
amplitude modulation in a recording. My knowledge of coding is limited
and online help isn't providing any answers. Any help on how to proceed
would be greatly appreciated.<BR><BR>Many
thanks<BR><BR>Tom<BR></TD></TR></TBODY></TABLE><BR></BLOCKQUOTE></BODY></HTML>