Identification of CDMA signal and GSM signal using the wavelet transform

Modulation identification has found wide applications in modern communication systems. This paper proposes a method to identify the OQPSK modulation type of IS-95 CDMA signal and the GMSK modulation type of GSM signal. The two signals have different transient properties because of their different modulation schemes. The idea of the proposed method is to use wavelet transform to extract the transient behaviors of the two signals, and then perform a template matching in the wavelet transform domain for identification. Simulation results showed that the percentage of correct identification was 98% at -3 dB E/sub b//N/sub 0/ with an observation period of 0.5 ms.