Space/time/frequency methods in adaptive radar - New Jersey ...

Figure 2.15 Scalogram of a multicomponent signaldensity. Discrete wavelet transforms are essentially subband coders and subbandcoders have been used in speech and image compression, wavelets may be used inthese applications easily. The field of discrete time wavelets (filterbanks, multiresolutionpyramids[38], and subband coding[39]) are beyond the scope of this work.2.3.4 Wigner-Ville DistributionThe STFT and Gabor Transform are both linear time-frequency representations.They are defined as linear representations because they satisfy the superposition orlinearity principle,In any application involving multicomponent signals, linearity is a desirable property.As has been shown in Figure 2.10, the STFT has a poor tradeoff between localizationand time-frequency resolution. These limitations have caused researchers tolook for other time-frequency representations. Several of the resulting time-frequency