RT - Journal Article T1 - Novel Features for Modulation Recognition Using an 8PSK Demodulator JF - jsdp YR - 2016 JO - jsdp VO - 13 IS - 2 UR - http://jsdp.rcisp.ac.ir/article-1-70-en.html SP - 3 EP - 10 K1 - automatic modulation classification K1 - feature extraction K1 - pattern recognition K1 - variants of QPSK K1 - Bayes classifier. AB - In this paper a feature-based modulation classification algorithm is developed for discriminating PSK signals. The candidate modulation types are assumed to be QPSK, OQPSK, π/4 DQOSK and 8PSK. The proposed method applies an 8PSK baseband demodulator in order to extract required features from observed symbols. The received signal with unknown modulation type is demodulated by an 8PSK demodulator whose output is considered as a finite state machine with different states and transitions for each candidate modulation. Estimated probabilities of particular transitions constitute the discriminating features. The obtained features are given to a Bayesian classifier which decides on the modulation type of the received signal. The probability of correct classification is computed with different number of observed symbols and SNR conditions by carrying out several simulations. The results show that the proposed method offers more accurate classification compared to previous methods for classifying variants of QPSK. LA eng UL http://jsdp.rcisp.ac.ir/article-1-70-en.html M3 ER -