fmpower

Purpose

Signal with power-law frequency modulation.

Synopsis

[x,iflaw] = fmpower(N,k,P1)
[x,iflaw] = fmpower(N,k,P1,P2)

Description

fmpower generates a signal with a power-law frequency modulation :

$$x(t) = \exp(j2\pi(f_0 t + \frac{c}{1-k} \vert t\vert^{1-k})).$$

Name	Description	Default value
N	number of points in time
k	degree of the power-law (k$\neq$1)
P1	if nargin==3, P1 is a vector containing the two coefficients (f0 c) for a power-law instantaneous frequency (sampling frequency is set to 1). If nargin=4, P1 (as P2) is a time-frequency point of the form (ti fi). ti is in seconds and fi is a normalized frequency (between 0 and 0.5). The coefficients f0 and c are then deduced such that the frequency modulation law fits the points P1 and P2
P2	same as P1 if nargin=4	optional
x	time row vector containing the modulated signal samples
iflaw	instantaneous frequency law

Example

         [x,iflaw]=fmpower(200,0.5,[1 0.5],[180 0.1]);
         subplot(211); plot(real(x));
         subplot(212); plot(iflaw);

See Also

gdpower, fmconst, fmlin, fmhyp, fmpar, fmodany, fmsin.

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