Practical PSK modulation classifier using wavelets

Automatic classification of different modulation schemes is an important topic in the receiver design for a non-cooperative communication system. The modulation classifier often serves as a pre-processing unit for a monitoring or interception system. The main difficulty of the problem lies in the uncertainty of the waveform and communication parameters of received signals. In this research, we first make a thorough comparison among four MPSK (M-ary phase shift keying) classifiers, i.e., the M-th power classifier (MLC), phase histogram classifier (PHC), phase difference histogram classifier (PDHC) and phase change classifier (PCC), in terms of their error classification probability and assumptions on the availability of various communication parameters. Then, we propose a novel MPSK classification algorithm based on the estimated phase change rate detected by using the continuous wavelet transform (CWT). Numerical experiments are used to demonstrate the performance of the proposed algorithm.