1st Edition

Time-Frequency Analysis Techniques and their Applications

By Ram Bilas Pachori Copyright 2023
    238 Pages 119 B/W Illustrations
    by CRC Press

    Most of the real-life signals are non-stationary in nature. The examples of such signals include biomedical signals, communication signals, speech, earthquake signals, vibration signals, etc. Time-frequency analysis plays an important role for extracting the meaningful information from these signals. The book presents time-frequency analysis methods together with their various applications.

    The basic concepts of signals and different ways of representing signals have been provided. The various time-frequency analysis techniques namely, short-time Fourier transform, wavelet transform, quadratic time-frequency transforms, advanced wavelet transforms, and adaptive time-frequency transforms have been explained. The fundamentals related to these methods are included. The various examples have been included in the book to explain the presented concepts effectively. The recently developed time-frequency analysis techniques such as, Fourier-Bessel series expansion-based methods, synchrosqueezed wavelet transform, tunable-Q wavelet transform, iterative eigenvalue decomposition of Hankel matrix, variational mode decomposition, Fourier decomposition method, etc. have been explained in the book. The numerous applications of time-frequency analysis techniques in various research areas have been demonstrated.

    This book covers basic concepts of signals, time-frequency analysis, and various conventional and advanced time-frequency analysis methods along with their applications. The set of problems included in the book will be helpful to gain an expertise in time-frequency analysis. The material presented in this book will be useful for students, academicians, and researchers to understand the fundamentals and applications related to time-frequency analysis.



    Chapter 1 Basics of signals

        1. Definition of signal
        2. Types of signals
        3. Various measures of the signals
        4. Important signals
        5. Signal operations

    Chapter 2 Signal representation

        1. Signal representation in terms of orthogonal functions
        2. Signal representation in terms of impulse functions
        3. Signal representation in terms of general basis functions
        4. Signal representation in terms of complex exponential functions
        5. Signal representation in terms of Bessel functions

    Chapter 3 Basics of time-frequency analysis

        1. Time-domain representation
        2. Time-domain localization
        3. Frequency-domain localization
        4. Heisenberg box representation
        5. AM and FM bandwidths
        6. Spectrum AM and PM durations
        7. Uncertainty principle
        8. Instantaneous frequency
        9. Basic ideas related to TFDs

    Chapter 4 Short-time Fourier transform

        1. STFT
        2. Time-frequency resolution of STFT
        3. STFT interpretations
        4. Reconstruction process for STFT
        5. Energy conservation for STFT
        6. Short-frequency Fourier transform
        7. Discrete version of STFT
        8. Examples of STFT

    Chapter 5 Wavelet transform

        1. Continuous wavelet transform
        2. Scalogram
        3. Features of CWT
        4. Inverse CWT
        5. Some properties of CWT
        6. Energy conservation in CWT
        7. Wavelet series
        8. Discrete wavelet transform
        9. DWT based on filter bank

    Chapter 6 Quadratic time-frequency transforms

        1. Quadratic time-frequency transforms
        2. Cross-term suppression in WVD
        3. General time-frequency distribution
        4. Implementation of Cohen’s class TFDs

    Chapter 7 Advanced wavelet transforms

        1. Wavelet packet transform
        2. Synchrosqueezed wavelet transform
        3. Rational-dilation wavelet transforms
        4. Tunable-Q wavelet transform
        5. Flexible analytic wavelet transform
        6. FBSE based flexible analytic wavelet transform
        7. Dual-tree complex wavelet transform

    Chapter 8 Adaptive time-frequency transforms

        1. Hilbert-Huang transform
        2. Ensemble empirical mode decomposition
        3. Variational mode decomposition
        4. Empirical wavelet transform
        5. FBSE based empirical wavelet transform
        6. Fourier decomposition method
        7. Iterative eigenvalue decomposition of Hankel matrix
        8. Dynamic mode decomposition

    Chapter 9 Applications

        1. Overview
        2. Automated detection of diseases using biomedical signals
        3. Disease detection and diagnosis from biomedical images .
        4. Extraction of vital signs from physiological signals
        5. Brain-computer interface
        6. TFA for speech processing
        7. Applications in communication engineering
        8. Power quality assessment

        1. Machinery fault diagnosis
        2. Chemical engineering
        3. Financial applications
        4. Ocean engineering



    Ram Bilas Pachori received the B.E. degree with honours in Electronics and Communication Engineering from Rajiv Gandhi Technological University, Bhopal, India in 2001, the M.Tech. and Ph.D. degrees in Electrical Engineering from Indian Institute of Technology (IIT) Kanpur, India in 2003 and 2008, respectively.

    He worked as a Post-Doctoral Fellow at Charles Delaunay Institute, University of Technology of Troyes, France during 2007-2008. He served as an Assistant Professor at Communication Research Center, International Institute of Information Technology, Hyderabad, India during 2008-2009. He served as an Assistant Professor at Department of Electrical Engineering, IIT Indore, India during 2009-2013. He worked as an Associate Professor at Department of Electrical Engineering, IIT Indore during 2013-2017 where presently he has been working as a Professor since 2017. Currently, he is also associated with Center for Advanced Electronics at IIT Indore. He was a Visiting Professor at Neural Dynamics of Visual Cognition Lab, Free University of Berlin, Germany during July-September, 2022. He has served as a Visiting Professor at School of Medicine, Faculty of Health and Medical Sciences, Taylor’s University, Malaysia during 2018-2019. Previously, he has worked as a Visiting Scholar at Intelligent Systems Research Center, Ulster University, Londonderry, UK during December 2014.

    His research interests are in the areas of Signal and Image Processing, Biomedical Signal Processing, Non-stationary Signal Processing, Speech Signal Processing, Brain-Computer Interfacing, Machine Learning, and Artificial Intelligence and Internet of Things in Healthcare.

    He is an Associate Editor of Electronics Letters, IEEE Transactions on Neural Systems and Rehabilitation Engineering, Biomedical Signal Processing and Control and an Editor of IETE Technical Review. He is a senior member of IEEE and a Fellow of IETE, IEI, and IET.

    He has 264 publications which include journal papers (162), conference papers (72), books (08), and book chapters (22). He has also three patents: 01 Australian patent (granted) and 02 Indian patents (filed). His publications have been cited approximately 12000 times with h-index of 57 according to Google Scholar. He has worked on various research projects with funding support from SERB, DST, DBT, CSIR, and ICMR.