(57) Abstract In a communication system including a transmitter and a receiver, the receiver is synchronized with the transmitter, and the modulation type of a signal transmitted by the transmitter and received by the receiver is detected. To detect the modulation type used, a first portion of the received signal is correlated with one or more signals representing the modulation type used in the communication system. Synchronization is established between the transmitter and the receiver. To detect the modulation type used, the first portion may be correlated with each of the one or more signals representing the various modulation types used in the communication system. Alternatively, the first portion of the received signal may be reverse-rotated by different amounts to generate a plurality of reverse-rotation signals, which reverse-rotation signal may be used to detect the type of modulation used. Is correlated with the signal representing the modulation used in the communication system. If the correlation does not output a determination of the modulation type, a predetermined modulation type is selected, or the modulation type is determined in a post-process based on, for example, a comparison or equalization result of signal quality.