Based on high-order cumulates, a novel recognition algorithm is proposed for LCP-GLSTBC (Group Layered Space-Time Block Coding) OFDM (Orthogonal Frequency-Division Multiple) signals to distinguish multi-carrier modulated signals (OFDM) from single-carrier modulated signals (MPSK and MQAM). The proposed algorithm can be used to directly process inter-frequency signals without the prior information about the transmit signal and the channel noise. Simulation results confirm the validity of the proposed algorithm and show that over 90% correct classification rate could be reached when SNR is above 5 dB.