Possible to break out complex WiFi signal?
The in-phase and quadrature components are easy to break out. You just need to demodulate using in-phase and quadrature local oscillators. See the diagram below.



The received signal $r(t,k)$ is mixed with a $\cos$ and a $-\sin$ wave of the appropriate frequency, and then low-pass filtered.

The actual IEEE 802.11 modulation schemes used are a little more complicated than indicated, but not overly so.