Novel blind modulation classification of circular and linearly modulated signals using cyclic cumulants

Abstract

This paper presents blind modulation classification algorithm of circular linearly modulated signals using cyclic cumulant. The classification uses positions of non-zero cyclic frequencies (symbol rate frequency or carrier frequency) of the received signals. The method works over flat and frequency selective fading channels without having any knowledge of the signal parameters and channel statistics. The proposed method is used for classifying circular constellation modulation format which has not been addressed before. It requires lower complexity than the maximum likelihood approach. The performance of this novel algorithm is compared with the existing methods. In this paper, we have considered a four-class problem including quadrature phase-shift keying (QPSK), offset-QPSK, π/4-QPSK, minimum shift keying.