Table 2.
Comparison of spectral analysis techniques.
| Feature | Fourier | Wavelet | Hilbert-Huang |
|---|---|---|---|
| Linearity required | Yes | Yes | No |
| Stationarity required | Yes | No | No |
| Frequency analysis | Yes | Yes; Marginal WT | Yes; Marginal HHT |
| Time –frequency analysis | Yes; STFT | Yes | Yes |
| Time–frequency resolution | Constant | Variable | Arbitrarily small |
| Spectrum smoothness | Low | Medium | High |
| Frequencies discovering | Medium | High | Very high |
| Non-linear modes discovering | No | No | Yes |
| Compression ratio | Medium | High | Low |
| Lossless compression ratio | Low | Low | High |
| Processing requirements | Low | Medium | High |