I was wondering what good method(s) exist for the estimation (and subsequent compensation) of doppler shift for transmitted signals, be they acoustic or RF, in the context of comms.
The question: Specifically, if the degree of doppler shift is varying over the duration of a packet, how best to estimate (track it?) and then compensate for it. Assume we have a trainer sequence. You may also assume the signal passband BW is on the order of its carrier. (e.g, if the passband signal exists from 2500-7500 Hz, its BW is 5000Hz, as is its carrier.)
Some additional background for context:
- One method I found during my research:
- Since I have a trainer sequence and know its frequency, first I estimate its received frequency.
- Next, I resample the entire packet by a ratio that is related to the speed of the wave in the medium, my known transmitted frequency, and my new estimated doppler shifted frequency.
- This works well in simulations, but the weak points are that the frequency estimation must be very accurate, and it also assumes the doppler shift is not changing during the duration of the packet.
Are there any other methods that can be utilized to solve the problem when the doppler is changing during the duration of the packet? What is the opinion of the above aforementioned method?