Is there anyway to get the I and Q components from a signal in the time domain? The signal has multiple frequencies.
So far I have been doing this in a SIMPLE situation:
- Fast fourier transform to get each frequency and each frequencies amplitude and phase
- Then use $\cos(\textrm{phase}) \cos(2 \pi f \times \textrm{time_vector}) - \sin(\textrm{phase}) \sin(2 \pi f \times \textrm{time_vector})$ for each frequency.
- This gives me I and Q data for each frequency, then I just need to sum them to getback the original signal.
Problem is, I am trying to do something more complex and need to get the I and Q data straight from the time domain signal without following the above steps. Where I is In phase component & Q is Quadrature phase component of the signal.