Algorithm for modulation classification of PSK signals

In a non-cooperative communication environment, the modulation mode of received signals has been widely concerned. Many methods are presented for estimating the modulation mode and order of common communication phase-shift key (PSK) signals, but they have weak points simultaneously. In this paper, a robust algorithm, using the periodicity of phase clustering and the differences of symbols´ phase difference, is proposed for classifying these communication PSK signals. It solves the recognition error brought by shaping filter and signal to noise ratio (SNR). Details of formulas and simulations are presented subsequently for verifying it.