Yes. Dunno if I'd call it reliable though grin. If you had this kind
of system on a moving vehicle for example the RX would have to be able
to follow the TX. You'll get about +-200Hz shift with a speed of 100kph.
(ie 400Hz as a vehicle goes past you)

I have been intending for ages setting up a 2m beacon on my car and
seeing if I can yield any driving location/speed etc info from the shift
and phase noise. (11Hz at 100kph)

Cheers Bob VK2YQA

mazerom wrote:

the doppler shift is fundamentally a tone frequency brought about by a
continuous wave source moving in and out. is it possible to have
reliable doppler shift when our source is spread spectrum or say some
form of digital modulation?