Hi Rhyston,
I understand that you want to modulate an audio signal using Single Sideband Suppressed Carrier (SSB-SC) modulation in MATLAB. You are seeking guidance on creating a Double Sideband (DSB) signal and filtering the sidebands for SSB modulation.
I assume you have already imported your audio signal and have access to its sampling frequency (fs).
In order to perform SSB-SC modulation on your audio signal, you can follow the below steps:
Create the DSB Signal:
Multiply your audio signal with a carrier signal to create a DSB signal. Use a cosine function for the carrier.
t = (0:length(audioSignal)-1)/fs; % Time vector
fc = 10000; % Carrier frequency, adjust as needed
carrier = cos(2*pi*fc*t);
dsbSignal = audioSignal .* carrier;
Apply Hilbert Transform:
Use the Hilbert transform to create an analytic signal, which helps in isolating the sidebands.
analyticSignal = hilbert(dsbSignal);
Generate the SSB Signal:
Use the real part of the analytic signal to create the SSB signal. This effectively removes one of the sidebands.
ssbSignal = real(analyticSignal);
Filter the Signal (if needed):
If further filtering is necessary to isolate a specific sideband, design and apply a bandpass filter.
% Example: Design a bandpass filter using "designfilt"
bpFilter = designfilt('bandpassfir', 'FilterOrder', 20, ...
'CutoffFrequency1', fc-500, 'CutoffFrequency2', fc+500, ...
'SampleRate', fs);
filteredSignal = filter(bpFilter, ssbSignal);
Plot the SSB Signal:
Visualize the SSB signal in the time domain to verify the modulation process.
plot(t, ssbSignal);
xlabel('Time (s)');
ylabel('Amplitude');
title('SSB-SC Modulated Signal');
Refer to the documentation of "hilbert" function to know more about creating analytic signals: https://www.mathworks.com/help/signal/ref/hilbert.html
Refer to the documentation of "designfilt" function for filter design: https://www.mathworks.com/help/signal/ref/designfilt.html
Hope this helps!
