Research on Recognition Algorithm of Digital Modulation by Higher Order Cumulants

Modulation identification of communication signals is an important content of wireless communication technology and a hot topic in the research field of the intercepted signal processing. Because the modulation mode is one of the most important characteristics to be used to distinguish various communication signals, in this paper, a new algorithm using feature parameters based on higher order cumulants has been proposed to identify digital modulation signals, which uses the feature of the white Gaussian noise of its greater than second-order cumulants is zero. Based on the analysis of invariant features in cumulant domain of communication signals, the performances of related cumulants have been researched, and at the same time the key cumulants and characteristics of modulation identification have also been determined. The proposed algorithm can identify digital modulation signals of 2ASK, 4ASK, 4PSK, 2FSK, 4FSK and 16QAM effectively under the environment of lower SNR. In addition, the results of simulation show that it can suppress white Gaussian noise effectively and has lower computational complexity and needs less prior information.