How to convert sampled real audio signal to it's IQ components for IQ modulation? So my question is this:
How to convert sampled real audio signal to it's IQ components for IQ modulation?

For instance:  WHen I have my DSP or FPGA receive a audio signal through a ADC, which is just the RAW A/D value.  Now I want to run this through a DAC to IQ modulator to get let FM modulation.
How would I convert the raw A/D value into IQ?  How do i break this signal down to In-phase and quadrature component? Do I do FM modulation in the DSP/FPGA and get the IQ from that or just split the audio baseband into it's IQ components?

Added:

I'm in the process of converting FSK transmitter from older obsolete design to newer  design.  So as I'm studying IQ, i was wondering what would happen if I  wanted to send a analog sine wave through the IQ modulator, like LTC5599.  How would I convert a analog sine wave to I and Q send it as input to the LTC5599?
I’ll answer the question I think you’re asking here:

If you have a real valued signal that came right out of an A/D and you’d like to recover signal phase, you can use the Hilbert transform to generate a version of the signal that is in quadrature with your A/D output. In this case, your original real valued signal would be the I component (in-phase) and the output of the Hilbert transform multiplied by j, the imaginary number, would be your Q component (quadrature).

Now if you have some modulation you want to deal with, you would do the IQ recovery first like I just described; once you have that IQ signal you’re pretty much completely characterized the signal, so you can do just about whatever you’d like with it while preserving phase.