Time-frequency distributions with complex argument

• Published in: IEEE transactions on signal processing Vol. 50; no. 3; pp. 475 - 486
• Main Author: Stankovic, L.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.03.2002; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Bias; Delay; Exact sciences and technology; Fourier transforms; Group delay; Information, signal and communications theory; Interference; Intermediate frequency; Multidimensional systems; Noise reduction; Quantum mechanics; Signal analysis; Signal and communications theory; Signal processing; Signal representation. Spectral analysis; Signal, noise; Spectral analysis; Spectrogram; Telecommunications and information theory; Time frequency analysis; Variance; Wigner distribution; Time frequency domain method; Frequency estimation; Instantaneous frequency; Non stationary process; Signal representation; Signal analysis; Spectral analysis; Wigner distribution; Group delay
• ISSN: 1053-587X; 1941-0476
• DOI: 10.1109/78.984717

A distribution highly concentrated along the group delay or the instantaneous frequency (IF) is presented. It has been defined by introducing a signal with a complex argument in time-frequency (TF) analysis. Realization of a signal with a complex argument, using a signal with a real argument, is described. The reduced interference realization of the complex argument distribution, in the case of multicomponent signals, is presented. The proposed distribution is used for the IF estimation. It is shown that the estimation can be improved with respect to the Wigner distribution based one since the bias can be significantly reduced with only a slight increase of the variance. The theory is illustrated by examples.