Estimate chirp shift Doppler

In his original post he never mentions noise (if fact he seems to be
doing  noise free simulations).

Offcourse a word of caution to real-world scenarios are always welcome,
but I don't see the point of adding arbitrary difficulty to the problem
and trying to implement sophisticated solutions when a simple one might
 work...


Afterall, this might be a simple exercise for a course....

Fox wrote:
> Hello,
> I have a question for you. I have to simulate the
> signal received in a radar system by applying a time delay and a
> doppler shift. By now I have delayed the original signal and I have
> estimated the delay by correlating the original transmitted signal
> with the received one and by picking the max. Now I have to estimate
> the shift in frequency but I don't know how to proceed. I think I
> should multiply the delayed signal for exp(-j*2pi*fd*t) but how can I
> estimate the shift? The transmitted signal is a chirp, duration of 100
> microsec sampled at 0.5 MHz (50 samples)
> Thanks in advance!

Ikaro wrote:

> In his original post he never mentions noise (if fact he seems to be
> doing  noise free simulations).
> Offcourse a word of caution to real-world scenarios are always welcome,
> but I don't see the point of adding arbitrary difficulty to the problem
> and trying to implement sophisticated solutions when a simple one might
>  work...

My dear Ikaro,

In the worlds of the spherical horses in the vacuum, the frequency is 
measured with the frequency counter. Just measure the zero crossing 
rate, what's the problem.


> 
> 
> Afterall, this might be a simple exercise for a course....
> 

The whole point of the exercise is that for the linear chirp the small 
Doppler shift is indistinguishable from the time shift...




VLV

dear ikaro,
              why dont you go for cylcostatinarity properties. i dont
know whether chirp signals qualify for such prorperties, for that do
refer william gardner's book on cyclostationarity. if chirp signals
come under cyclostatinarity signals, then frequency shift evaulation is
easy, never mind even under worse SNR Conditions as mentioned in one of
the letters.

anyway, by next post i will come up with some answer for your problem

regards
particle (filter) reddy