Modulation Information in Communication Signals is Embedded in Instantaneous Amplitude, Phase, and Frequency Variations
Modulation information in communication signals is embedded in variations of instantaneous amplitude, phase, and frequency, with different signals exhibiting unique spectral characteristics. By extracting statistical parameters from instantaneous amplitude, phase, frequency, and spectral features, various communication signals can be identified. Commonly, transformations are applied to instantaneous amplitude, phase, frequency, and power spectral density to derive discriminative feature parameters. In practice, this involves algorithms like Hilbert transform for instantaneous attributes calculation and Fourier analysis for spectral feature extraction.