Blind recognition algorithm of mixed MPSK signals based on constellation diagram

A blind modulation recognition algorithm based on constellation diagram is proposed for modulation recognition of mixed MPSK signals in single channel.The algorithm uses cyclic spectrum characteristics of mixed signals to estimate the carrier frequency.It reconstructs the constellation diagrams of mixed signals via subtractive clustering,and extracts the number of cluster centers as the classification feature.It selects the appropriate thresholds to achieve category judgment.Simulation results show that algorithm has good performance on recognition of mixed MPSK signals when SNR is above 15dB,and it is less affected by energy ratio between signals.