Signal Adaptive Method for Improved Space/Spatial-Frequency Representation of Nonstationary Two-Dimensional Signals

This paper represents a signal adaptive two-dimensional (2-D) method for space/spatial-frequency (S/SF) signal analysis. The method is capable of taking a variable number of execution steps (the only necessary ones regarding desirable–2-D Wigner distribution–presentation of auto-terms) in different frequency-frequency points during the execution. This ability represents a major advantage of the proposed method which helps optimize the time required for execution and produce an improved, cross-terms-free S/SF signal representation. Additionally, the proposed method improves noisy signal representation. Key-Words: Space/Spatial analysis, 2-D Wigner distribution, 2-D STFT, Noisy signal analysis, Cross terms, Optimal auto-terms representation, Signal adaptive method 1 Theoretical background The 2-D STFT, its energetic version (2-D SPEC) and the 2-D WD are conventional mathematical methods, used in S/SF signal analysis. They are defined, in vector notation, as [1]–[3]: 2 ( , ) ( ) ( ) j km N m STFT n k w m f n m e − = + ∑ rr