Parabolic frequency modulated signal.
[X,IFLAW]=fmpar(N,P1) [X,IFLAW]=fmpar(N,P1,P2) [X,IFLAW]=fmpar(N,P1,P2,P3)
the number of points in time
if NARGIN=2, P1 is a vector containing the three coefficients [A0 A1 A2] of the polynomial instantaneous phase. If NARGIN=4, P1 (as P2 and P3) is a time-frequency point of the form [Ti Fi]. The coefficients (A0,A1,A2) are then deduced such that the frequency modulation law fits these three points.
same as P1 if NARGIN=4. (optional)
time row vector containing the modulated signal samples
instantaneous frequency law
fmpar generates a signal with parabolic frequency modulation law. X(T) = exp(j*2*pi(A0.T + A1/2.T^2 +A2/3.T^3))