Sensors & Transducers (Sep 2014)
A Novel Digital Signal Modulation Mode Recognition Algorithm
Abstract
Digital modulation signal instantaneous characteristics are susceptible to noise interference, and instantaneous frequency extraction is easy to be folded and distorted. In this paper, a novel digital signal modulation mode identification algorithm under low SNR is proposed. In the algorithm, empirical mode decomposition (EMD) has been employed to extract signal instantaneous characteristics firstly; and then instantaneous characteristics has been preprocessed by using wavelet de-noising; finally five characteristic parameters have been calculated to recognize seven kinds of digital modulation signal. The simulation results show that the instantaneous frequency can get actual physical meaning using proposed algorithms with higher recognition efficiency under low SNR.