Blind Modulation Classification Algorithm for Single and Multiple-Antenna Systems Over Frequency-Selective Channels

This letter proposes a blind modulation classification (MC) algorithm applicable to single and multiple-antenna systems operating over frequency-selective channels. We show that the correlation functions of the received signals for certain modulation formats exhibit peaks at a particular set of time lags, a result which can be exploited as a discriminating feature. We also develop a new hypothesis test in order to detect the correlation-induced peaks. The proposed algorithm is general in the sense that it accommodates any number of transmit- and receive-antennas, without prior information about channel statistics. The classification performance of the proposed algorithm is assessed through Monte Carlo simulations.