Modulation classification method for OFDM subcarrier under carrier frequency offset

A modulation recognition algorithm based on signal amplitude distribution and higher-order spectral characteristics was presented. The algorithm mainly utilized the amplitude distribution of orthogonal frequency division multiplexing subcarrier signal after orthogonal demodulation by inverse Fourier transform, realized multiplexing phase shift key and orthogonal amplitude modulation recognition by histogram statistics, and the modulation order in the multiplexing phase shift key class was recognized by multi-spectral analysis. Compared with the classical modulation recognition algorithm based on high-order cumulant, it has better adaptability to carrier frequency residual deviation, and the recognition rate is improved under the condition of carrier frequency offset. Compared with the cyclostationary method, it has better signal-to-noise ratio adaptability. The simulation results show the effectiveness of this method. Under the same recognition rate, the adaptability is improved. The simulation results show the effectiveness of this method.