Signal with power-law group delay
[X,GPD,F] = gspower(N, K, C)
an even positive integer: number of points in time
a real scalar: the degree of the power-law (default : 0)
a real non zero scalar: the rate-coefficient of the power-law group delay. (default : 1)
a real column vector: the modulated signal samples
a real row vector (length : round(N/2)-1): the group delay (length : round(N/2)-1)
a real row vector (length : round(N/2)-1): the frequency bins
generates a signal with a power-law group delay of the form tx(f) = T0 + C*f^(K-1). The output signal is of unit energy.