<< fmconst Choice of the Instantaneous Frequency fmlin >>

stftb >> stftb > Choice of the Instantaneous Frequency > fmhyp

fmhyp

Signal with hyperbolic frequency modulation

Calling Sequence

[X,IFLAW] = fmhyp(N, P1, P2)

Parameters

N :

a positive integer: number of points in time

P1 :

a real 2 elements vector:

if the number of input arguments is 2, P1 is a vector containing the two coefficients [F0 C] for an hyperbolic instantaneous frequency .

if the number of input arguments is 3, P1 is a time-frequency point of the form [t,f]. where t is in seconds and f is a normalized frequency (between 0 and 0.5).

P2 :

a real 2 elements vector:

P2 is a time-frequency point of the form [t,f]. where t is in seconds and f is a normalized frequency (between 0 and 0.5).

X :

real column vector: the modulated signal time samples. Sampling frequency is set to 1.

IFLAW :

real column vector: instantaneous frequency law

Description

fmhyp generates a signal with hyperbolic frequency modulation : X(t) = exp(i.2.pi(F0.t + C/log|t|)). When called with 3 input arguments F0 and C are derived from P1 and P2 such that the frequency modulation law fits the points P1 and P2.

Examples

[X,IFLAW] = fmhyp(128,[1 .5],[32 0.1]);
clf
subplot(211); plot(real(X)); xtitle(_("Signal real part"))
subplot(212); plot(IFLAW); xtitle(_("Instantaneous frequency law"))

See also

Authors


Report an issue
<< fmconst Choice of the Instantaneous Frequency fmlin >>