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gdpower



Purpose
Signal with a power-law group delay.


Synopsis
[x,gpd,f] = gdpower(N)
[x,gpd,f] = gdpower(N,k)
[x,gpd,f] = gdpower(N,k,c)


Description
gdpower generates a signal with a power-law group delay of the form

\begin{displaymath}t_x(f) = t_0 + c\ f^{k-1}.\end{displaymath}

The output signal is of unit energy.

Name Description Default value
N number of points in time (must be even)  
k degree of the power-law 0
c rate-coefficient of the power-law group delay. c must be non-zero. 1
x time row vector containing the signal samples  
gpd output vector containing the group delay samples, of length round(N/2)  
f frequency bins  




Examples
Consider a hyperbolic group-delay law, and compute the Bertrand distribution of it :
         sig=gdpower(128); 
         tfrbert(sig,1:128,0.01,0.3,128,1);
We note that the perfect localization property of the Bertrand distribution on hyperbolic group-delay signals is checked in that case.
Plot the instantaneous frequency law on which the D-Flandrin distribution is perfectly concentrated :
         [sig,gpd,f]=gdpower(128,1/2); 
         plot(gpd,f); 
         tfrdfla(sig,1:128,.01,.3,218,1);


See Also
fmpower.

Eric Chassande-Mottin 2005-10-26

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