vestigial side band modulation

what is the code to get vestigial side band modulation and demodulation??

Answer 1

[Arun]

Hi Chandana Kiran,

I understand that you are looking for some reference implementation of vestigial side band modulation and demodulation in MATLAB.

Here are few reference link that might be useful:

1. MATLAB Answer, "Vestigial side band code": https://www.mathworks.com/matlabcentral/answers/486225-vestigal-side-band-matlab-code
2. Single sideband amplitude modulation (ssbdemod) function: https://www.mathworks.com/help/comm/ref/ssbdemod.html

Hope this helps!

Regards

Arun

Answer 2

[Ritesh]

%% message signal m(t)=u(t+2)-u(t-2)

syms t f

fc=10;%let carrier frequency frequency contain 10 Hz .x_carrier=cos(2*pi*10*t)

x = heaviside(t+2)- heaviside(t-2) %% Fourier transform of m(t)

X=fourier(x,f) ;% fourier transform

%% using anonymous function

XX = @(f) 2*(sin(2*f)./(f))

f=[-100:0.01:100-0.01];% proper frequency range .Avoiding 0 / 0.

%% Generation of DSB-SC

Xshift=( XX(f-fc)+XX(f+fc));

%% Designing VSB shaping filter characteristic

% Define normalized VSB shaping filter

Hf = @(f) ((f>=9 & f<=20)) ;

%% Generating SSB

SSB =@(f) Xshift.*(f>=10 & f<=50) + Xshift.*(f<=-10 & f>=-50);

%%Here I am just plotting SSB-SC and VSB modulation signals.you can also

%%plot Hf(f) characteristic normalized filter and DSB-SC from equation.

%% Generation of VSB

VSB_upper = @(f)((XX(f-fm)+XX(f+fm)).*Hf(f)) %SSB(f).*Hf(f)SB_upper = @(f)((XX(f-fm)+XX(f+fm)).*Hf(f)) %SSB(f).*Hf(f)

subplot(211)

%% ploting SSB

plot(f,abs(SSB(f)),[-10,-10],[0,4],[10 10],[0,4],'r','linewidth',1.5);

% set axis for visualize porpuse only

xlim([-35 35]);

grid on;ylim([0 6]);xlabel('frequency in Hz');ylabel('Magnitude spectrum');

legend('| SSB-SC|');

title('Single Sideband Modulation');

%% ploting VSB

subplot(212)

plot(f,abs(VSB_upper(f)),'b',-f,abs(VSB_upper(f)),'k','linewidth',1.5);grid on;

xlabel('frequency in Hz');ylabel('Magnitude spectrum');

title('SSB');ylim([0 6]);legend('| VSB |');

% set axis for visualize purpose

xlim([-35 35]);

% see carefully around 10 Hz .A vestige was found before +10 Hz and also in

% case negative -10 Hz