Study of a Novel Key Feature in Non-Cooperative Modulation Automatic Recognition

For both analogue and digital modulation types, we proposed a general signal expression and studied the non-cooperative automatic recognition synthetically, which is more useful and universal than separate research. The proposal of a new key feature, i.e. the variance of normalized instantaneous amplitude, with the benefit of less computationally demanding and excellent correct classification rate in low SNR, can be used to discriminate between the signals that have amplitude information and that have no amplitude information. We concluded a set of the parameter's whole and accurate theoretical expressions for several signals, especially for the amplitude modulated signals with different modulation depths and audio modulated single side band signals. Illustrative simulation examples were provided at last.