Hi boroko,
It is not uncommon to send power and r/f through a common line, each end of the wire has a choke and capacitor attached. The d/c goes through the chokes and the A/C goes through the caps, though I do not think you can send serial data that way unless you first convert it to HF radio type signal. Heck, give it a try, what's the worst case scenario, fry a 3 dollar chip ?