Modulation identification of OFDM based on wavelet transform in multi-path channels

摘要

Wavelet transform (WT) is suitable for detecting transient signals，by which the instantaneous features of digital signals will be easily presented when the symbols change. This paper studies the use of wavelet transform to distinguish Orthogonal Frequency Division Multiplexing (OFDM) and single carrier (SC) digital signals in multi-path communication channels. The approach applies WT on OFDM and SC digital signals twice (WT-T) to extract the transient features of them, and then by using the transient features in WT-T domain, it is easy to identify the two types of signals. The principle and performance of the identifier is investigated through analysis and simulations. The simulation results show that the percentage of correct identification is higher than 98% in multi-path channels when SNR is 0dB.