My question is about I Q samples as recorded from an SDR receiver (e.g. RTL-SDR).
My understanding is that we can call these I Q samples a complex time domain signal and these can have both non-zero real and imaginary components (the question I linked above is talking about zero imaginary part in the time domain).
Is there an intuitive explanation of what is the meaning of this type of complex time domain signal?
I can think of taking a simple case of an input sine wave of a frequency below the sampling frequency which would make the IQ signal's phasor rotate with the frequency equal to the difference between the input sine wave's frequency and the sampling frequency thus allowing to unambiguously reconstruct frequencies up to (but not including) the sampling frequency from the IQ samples.
But I'm struggling to extend this special case to an input composed of several sinusoids of different frequencies.