Effect of Carrier Offset on the Classification of Phase Shift Keying Modulation using the Subtraction of Two Consecutive Signal Values

In this paper we study the effect of carrier offset on a feature distinguishing binary phase shift keying and quadrature phase shift keying. The feature is based on the subtraction of two consecutive signal values and the kurtosis of the absolute value of this subtraction. The paper compares performance of the proposed feature to a cumulant based feature when both are used in a support vector machine classifier. Also the paper compares the proposed-feature based classification to the maximum likelihood classification and to the quasi-log-likelihood ratio classifier. The simulation results showed that the proposed feature classifier has a robust performance with respect to carrier offset compared to the other above mentioned classifiers.