How to extract features out of the signal using fft for automatic modulation identification.

An algorithm was designed and implemented in MATLAB. It extracts all the spectral components of the up-sampled signal using FFT. All the frequency peaks calculated were stored in an array vector in the work space. Variance in the values contained within this array was calculated and this variance was taken as the frequency feature of the signal, values at four different SNR‟s are given in table 5-1.<<http://postimage.org/image/b09x3b0ut/>> if anybody interested to answer i can email you my simulink model