Automatic modulation classification and measurement of digitally modulated signals

In the paper the Zero-Crossing-Sequence Shape method is described. The method effectively classifies the M-Ary PSK and M-Ary FSK modulated signals detecting both the phase and frequency shifts in the incoming signal by using the zero-crossing and instantaneous frequency variation sequences. Moreover, from these sequences, independently from the modulation classification, the Carrier-to-Noise-Ratio (CNR), the carrier frequency and the symbol rate are also determined. In order to make the method able to operate at lower CNR, preprocessing of the instantaneous frequency sequence and statistic hypothesis are assumed. Experimental results confirm both the high accuracy and the performance of the method.