I have two signals stored in vectors, one of them is a 4-QAM baseband signal(m), and the other is a simple Local Oscillator sinusoid signal(Lo). Then I've simulated the mixing like this:
and then i filtered out the low frequency component of Rsignal, but after that, the radio signal doesn't look like the baseband, and I couldn't get back the digital data after demodulation. I know there are mixer objects in Simulink, but i want to use matlab coding, because it's much more practical. So I'm looking for a coding solution to properly mixing the baseband and the Lo signals in such a way that the Rf signal looks similar to the baseband.
Thanks a lot.