From d2f4d30ebcad7430e4f0495cae5c2b3a16be73ce Mon Sep 17 00:00:00 2001 From: rupak Date: Tue, 21 Jan 2020 19:05:09 +0530 Subject: added help files --- help/en_US/scilab_en_US_help/ssbdemod.html | 110 +++++++++++++++++++++++++++++ 1 file changed, 110 insertions(+) create mode 100644 help/en_US/scilab_en_US_help/ssbdemod.html (limited to 'help/en_US/scilab_en_US_help/ssbdemod.html') diff --git a/help/en_US/scilab_en_US_help/ssbdemod.html b/help/en_US/scilab_en_US_help/ssbdemod.html new file mode 100644 index 0000000..1fe5a1a --- /dev/null +++ b/help/en_US/scilab_en_US_help/ssbdemod.html @@ -0,0 +1,110 @@ + + + ssbdemod + + + +
+ + + + +
+ << octave_functions + + + FOSSEE_Communication_Systems_Toolbox + + + +
+
+
+ + + + FOSSEE_Communication_Systems_Toolbox >> FOSSEE_Communication_Systems_Toolbox > ssbdemod + +

+

ssbdemod

+

This function performs Single Side Band Amplitude Demodulation

+ + +

Description

+

Z = SSBDEMOD(Y,Fc,Fs) +demodulates the single sideband amplitude modulated signal Y +with the carrier frequency Fc (Hz). +Sample frequency Fs (Hz). zero initial phase (ini_phase). +The modulated signal can be an upper or lower sideband signal. +A lowpass butterworth filter is used in the demodulation.

+

Z = SSBDEMOD(Y,Fc,Fs,INI_PHASE) +adds an extra argument the initial phase (rad) of the modulated signal.

+

Z = SSBDEMOD(Y,Fc,Fs,INI_PHASE,NUM,DEN) +adds extra arguments about the filter specifications +i.e., the numerator and denominator of the lowpass filter.

+

Fs must satisfy Fs >2*(Fc + BW), where BW is the bandwidth of the +modulating signal.

+

+

+ +

Examples

+ 
Fs =200;
+t = [0:2*Fs+1]'/Fs;
+ini_phase = 5;
+Fc = 20;
+fm1= 2;
+fm2= 3
+x =sin(2*fm1*%pi*t)+sin(2*fm2*%pi*t);
+y = ssbmod(x,Fc,Fs,ini_phase);
+o = ssbdemod(y,Fc,Fs,ini_phase);
+z = fft(y);
+zz =abs(z(1:length(z)/2+1 ));
+axis = (0:Fs/length(zz):Fs -(Fs/length(zz)))/2;
+
+figure
+subplot(3,1,1); plot(x);
+title(' Message signal');
+subplot(3,1,2); plot(y);
+title('Amplitude modulated signal');
+subplot(3,1,3); plot(axis,zz);
+title('Spectrum of amplitude modulated signal');
+z1 =fft(o);
+zz1 =abs(z1(1:length(z1)/2+1 ));
+axis = (0:Fs/length(zz1):Fs -(Fs/length(zz1)))/2;
+figure
+subplot(3,1,1); plot(y);
+title(' Modulated signal');
+subplot(3,1,2); plot(o);
+title('Demodulated signal');
+subplot(3,1,3); plot(axis,zz1);
+title('Spectrum of Demodulated signal');
+ +

Authors

+
+
+ +
+ + + + + + +
Report an issue
+ << octave_functions + + + FOSSEE_Communication_Systems_Toolbox + + + +
+
+
+ + -- cgit