Dr. G. Abhilash
Dr. G. Abhilash

Associate Professor

Office Address:

ECED-1 : 301, Department of Electronics and Communication Engineering National Institute of Technology Calicut, Kerala, India

Contact no:


Home Address:

Faculty Quarter No. C-8 (Near the Valley), NITC Campus, National Institute of Technology, Calicut, Kerala, India 673 601

  • PhD (Signal Processing) (IISc)

  • ME (Communication Engineering) (IISc)

  • BSc(Engg) (Electronics and Communication Engineering) (CET, Kerala University)

  • Educational Qualifications

    • PhD (Signal Processing) (IISc)

    • ME (Communication Engineering) (IISc)

    • BSc(Engg) (Electronics and Communication Engineering) (CET, Kerala University)


    ORCID: 0000-0002-9365-4403

    1) Teaching (Classroom; one or two courses in a semester)

    • Compressed Sampling: Principles and Algorithms (B.Tech)
    • Linear Algebra for Signal Processing (M.Tech)
    • Compressive Sensing: Theory and Algorithms (M.Tech)
    • Wavelets: Theory and Construction (B.Tech) (M.Tech)
    • Multirate Systems and Filterbanks (B.Tech) (M.Tech)


    • Analog Communication Theory (B.Tech)(Winter) 
    • Wavelets: Theory and Construction (B.Tech/M.Tech)(Monsoon/Winter)
    • Digital Communication Theory (B.Tech)(Monsoon)
    • Speech Signal Processing (B.Tech)(Winter/Monsoon)
    • Multirate Signal Theory (M.Tech)(Monsoon 2006, 2010); (B.Tech)(Winter 2011)
    • Electronic Circuits (B.Tech) (Winter 2006, 2010)
    • Signals and Systems (B.Tech)(Monsoon 2007)
    • Linear System Theory (M.Tech) (Monsoon 2008, 2013)
    • Digital Signal Processing (B.Tech) (Monsoon 2012)

    Current Semester: Signals and Systems (B.Tech); Linaer Algebra and Analysis (M.Tech)

    2) Teaching (Laboratory)

    • Electronic Circuits (Winter)
    • Analog Communication (Monsoon)
    • Digital Communication (Winter)
    • Wavelets (Part of the course-work)(Monsoon & Winter)
    • Digital Signal Processing (Winter, B.Tech; Monsoon / Winter, M.Tech)
    • Compressive Sensing and Recovery (Part of the course-work) (B.Tech) (M.Tech)
    • Multirate Systems and Filterbanks (Part of the course-work)(B.Tech)

    3) Seminar/Project Coordination

    • B.Tech Project Coordinator (2011 – 2012, 2012 - 2013, 2013 - 2014)
    • B.Tech Seminar Coordinator (Monsoon, 2007; Winter 2017, 2018, 2019)
    • B.Tech Minor Project Coordinator (Winter 2017)

    4) General subject interests

    • Signal Theory
    • Functional Analysis
    • Operator Theory
    • Topology and Topological Spaces

    5) Research

    • Compressive Sensing and Recovery of Signals
    • Sparse Modelling
    • Inverse Problems in Signal Processing
    • Learning Algorithms for Signal Processing
    • Mathematical Modelling of Learning and Cognition in Biological Brains (Freelance Research)

    6) Learning

    •  Topology and Topological Spaces
    •  Quantum Science, Computing, and Signal Theory

    7) Additional activities

    • Member of the Project Monitoring Committee, Design Innovation Center, NIT Calicut. (Funded by Government of India (Ministry of Education) through the Indian Institute of Science Bangalore as the nodal center) (January 2016 - Continuing)
    • Researcher, Signals Research Laboratory
    • Member, Board of Post Graduate Studies (2006 June - 2010 July)
    • Member, Central Library Advisory Committee (2018 - Continuing)
    • Member, Central Library Purchase Committee (2013 - 2017)
    • Member, M.Tech (SP) Project Evaluation Panel (2018 - Continuing)
    • Advisor, IEEE Signal Processing Society (Student Branch) Chapter NIT Calicut (Approved on 8 March 2018, Geocode SBC21881G)

    8) Membership

    • Member IEEE,
    • IEEE (Signal Processing Society)
    • IEEE (Information Theory Society)

    2) Teaching (Laboratory)

    • Electronic Circuits (Winter)
    • Analog Communication (Monsoon)
    • Digital Communication (Winter)
    • Wavelets (Part of the course-work)(Monsoon & Winter)
    • Digital Signal Processing (Winter, B.Tech; Monsoon / Winter, M.Tech)
    • Compressive Sensing and Recovery (Part of the course-work) (B.Tech) (M.Tech)
    • Multirate Systems and Filterbanks (Part of the course-work)(B.Tech)


    The Signals Research Laboratory is an activity taken up voluntarily by the young students, mostly B. Tech, Researchers and motivated faculty members. We focus on the mathematical aspects of Signal Theory. There are discussions and interaction with working engineers of industry to know about and work on the technical issues they face. We also offer special lectures on selected topics to students to empower them carry out innovative project works successfully. We are also preparing student monographs on selected topics.

    We have been using the existing facilities of the institute that are freely accessible to the students. Thus, the Lab has been "distributed".

    India has human resources aplenty; the harmonious utilization of it can fetch growth and joy. Money is human effort. We exert ourselves willfully and it fetches immense confidence and a clean sense of self-reliance.

    Academic/Research Activities:

    1) Special lecture series (for B.Tech/M.Tech, NITC; forthcoming):

    • Fractional Fourier transform: Theory, algorithm and applications (approx. 12 Hours) 
    • Z-Transform: Its formulation (approx. 8 Hours) 
    • Frame theory (approx. 30 Hours, spanning four working weeks)
    • Quantum Sicience for Quantum Computing and Signal Theory

     2) Special lecture series (past):

    • Continuous Wavelets and Wavelet Transforms: Principles and Applications (Mastery Program for Youths, January 20 - 24, 2023) (IEEE Signal processing Society (SB) Chapter NIT Calicut and ECE Association (Department of ECE) NIT Calicut)
    • Multi-resolution analysis and Wavelet Design (Mastery Program for Youths, June 12 -27, 2019) (IEEE Signal Processing Society (SB) Chapter NIT Calicut)
    • Signal Theory: A Foundation for the Design of Signal Processing Systems (Mastery Program for Youths, June 5 - 30, 2017) (Sponsored by the Design Innovation Center, NIT Calicut)
    • Poles, Zeros and the Construction of Transforms (For B.Tech, from 1 June 2011 to 28 June 2011.
    • Compression Sampling (Lectures + Lab) (For B.Tech, from 8 June 2009 to 27 June 2009)
    • Wavelets: Theory and Construction - A Signal-Theoretic Approach (Invited lecture, 2 Hours, Government Engineering College Barton Hill, Thiruvananthapuram; March 6, 2009)
    • Theory and Design of Linear Time Invariant Systems (Electronic Circuits): Pole-Zero Placement Techniques (along with Hardware Laboratory sessions) (7 days, for B.Tech, NITC; July, 2008)
    • Continuous Wavelet Transform: Theory and Practice (6 Hours, for B.Tech, NITC; August 2007)
    • Multirate signal theory: From sampling theorem to filter bank design (15 Hours, for B.Tech, NITC; August 2006)
    • Wavelets: A signal theoretic perspective (Invited lecture, UGC sponsored regional seminar on recent trends in Functional Analysis, Department of Mathematics, Farook College, Kozhikkode, March 8, 2006)
    • A-law and Mu-law Companding: Formulation from first principles (8 Hours, for B.Tech, NITC; January-February 2006)
    • Speech coding: Linear prediction - Theory and algorithms (15 Hours, for B.Tech, NITC; July 2002; January 2005; February 2006; January 2008)
    • Wavelets (Invited lecture, 1.5 Hours, Organized by IEEE, IE, Center for Bio-mechanics NITC; March 2005)
    • Wavelets (Invited lecture, 8 Hours, NSS College of Engineering., Palakkad; July 2003)

    3) Internship Projects:

    (1) B.Tech

    • System Identification using the principles of Linear Prediction (Student: Garvita Basantani, NIT Raipur) (Summer 2021)
    • Fractional Fourier Transform: Theory, Algorithm and Applications (vacant)(Summer 2021) (for pre-final year students of ECE/EEE)
    • Analysis, Design, Realization and Testing of Feedback Amplifiers, and RF circuits for Analog Communication (Completed)

    (2) M.Tech

    • Fundamentals of Compressive Sampling

    4) Upcoming Projects:

    • Compression Sampling of Analog Signals.
    • Blind Compressive Sensing and Recovery.
    • Sparse Modelling and Statistical Learning with Sparsity.

    1) B.Tech: Main project (Final year):

    • Status: [Vacant] [1 Position]

    3) M.Tech: Main Project (Final year):

    • Status: [Assigned] [1 Position] (2023 -24)
    • Status: [Vacant] [1 Position] (2024-25)


    • Inclination to carry out rigorous mathematical analysis.
    • Knowledge of MATLAB or any other programming language suitable for scientific computation.

    Special lectures: (offered as part of the project schedule for undergraduate students only):

    • Selected topics in Linear Algebra, Functional Analysis and Linear Operators
    • Selected topics in Signal Theory: Quantum Signal Processing
    • Selected topics in Wavelets: Construction of Continuous Wavelets in a Quantum Mechanical Framework.

    Remark: These project works come under the Signals Research Laboratory activity.

    1) B.Tech: Mini projects

    • Linear Predictive Coding of Speech Signals Using Levinson Recursion (Software) (May 2018)
    • Lattice realization of notch filters (Software)(May 2018)
    • Linear Predictive Coding of Speech Signals Using Schur Algorithm (Software + Hardware) (May, 2011)   
    • Design and Implementation of Adaptive Delta Modulation and Transmission over a microwave Link (Software + Hardware) (May, 2011)
    • Compressive Sampling using Random Demodulation (Software + Hardware) (April, 2010)
    • Design and Implementation of Channel equalizers (Software + Hardware) (April, 2010)
    • Design and Implementation of an Analog Delay Line (Software + Hardware) (May, 2009)
    • Analysis, Modeling, Design and Testing of Feedback Amplifiers (Software + Hardware) (May, 2009)
    • Design of a limited vocabulary, isolated-word speech recognizer (Software) (July, 2008)
    • Design and implementation of a 2-channel switched-capacitor filter bank (Hardware) (July, 2008)
    • Arithmetic Fourier transform: Theory and implementation (Hardware + Software) (July, 2008)
    • Design of a low phase-noise DSP oscillator (Hardware + Software) (July, 2008)
    • Spectral analysis of irregularly sampled sequences (Hardware + Software) (July, 2006)
    • Code Excited Linear Predictive Coding of speech signals (Hardware + Software) (July, 2006)
    • A-law and Mu-law companding: Principles, formulation and implementation (Hardware + Software) (July, 2006)
    • Speech analysis and synthesis using linear predictive coding (Hardware + Software) (August, 2005)
    • Hardware implementation of Levinson/Schur algorithm employing lattice filter structure (April, 2004)
    • Clock recovery from Random NRZ data (Hardware) (April, 2003)
    • Space-Time-Space switch for data communication (Hardware) (April, 2003)
    • Speech coding at low bit rates using DPCM/ADPCM schemes (Hardware + Software) (April, 2003)

    2) B.Tech: Major Projects (Final year)

    • Training-free Super-resolution Techniques for Feature Extraction in images: An Exploratory Study (May, 2019)
    • Compressive Sampling / Reconstruction Through Power Spectrum Reduction / Extension (May, 2012)
    • IIR filter Bank Design for Compressive Sampling (May, 2012)
    • Compressive Sampling of Analog Signals (May, 2012)
    • Two-dimensional Filter Banks for Sparse Representation of Two-Dimensional Signals (May, 2012)
    • Compressive Sampling: Filter Bank Design and Spectral Extension Techniques (May, 2011)
    • Compressive Sampling of Analog Signals: A Multi-band Approach (April, 2010)
    • Recovery Techniques in Compressive Sampling (April, 2010)
    • Fractional Fourier Transform and Its Applications (April, 2009)
    • Compressive Sampling: A Spiking Filter Approach (April, 2009)
    • Cross-Wavelet Transforms: Theory, Implementation and Applications (April, 2008)
    • Perfect Reconstruction Filterbanks: Orthogonal design - Theory, Implementation and Application (April, 2007)
    • Perfect Reconstruction Filterbanks: Biorthogonal design - Theory, Implementation and Application (April, 2007)
    • Wavelets:Theory, construction and application in the analysis of power system transients (Department of EEE) (Jointly with Dr. R. Sreeramkumar, Professor, EED)(April, 2006)
    • VHDL simulation of Convolution coder and Viterbi decoder for Binary Symmetric Channel (May, 2004)

    3) M.Tech: Major Projects

    • Recovery/Reconstruction Algorithms for Blind Compressive Sensing (July, 2022)
    • A Study on Phase Retrieval Algorithms (July, 2021)
    • Construction and Applications of Frames for Robust Signal Processing (August, 2021)
    • Sparsity-Aware Linear Canonical Transforms (June, 2020)
    • An Exploration into Blind Compressed Sensing and Recovery (June, 2019)
    • Classification and Dimensionality Reduction using Graph Techniques (June, 2018)
    • Image Denoising via Sparse Coding Through Learned Graph Dictionaries (June, 2018)
    • Linear Canonical Transform and its Applications (May, 2014)
    • Reproducing Kernel Hilbert Spaces and its Applications (May, 2014)
    • An Exploration into Sparse Representation and Recovery of Signals (May, 2013)
    • Compressive Sampling Through Information Extraction (May, 2011)
    • Compressive Sampling: Theory and Practice - A Study (June, 2009)
    • Filter Banks Over Real, Non-finite and Finite Fields: A study (June, 2009)
    • Theory, Construction and Applications of Multiwavelets: A Study (July, 2007)
    • Electronic surgical tourniquet (Product development for medical application) (May, 2004)
    • Fractional Fourier transform: Theory, Algorithm and Applications - A study (April, 2003)

    Remark: All these project works come under the Signals Research Laboratory activity.

    The areas of research I am working in are:

    1) Compressive Sensing

    Status: [Assigned] [July 2018] [Full-time] (Student : Veena Narayanan)

    Quantum Signal Processing

    Status: [Vacant] [Full-time] (1 Position)


    • The prospective regular (Full-time) research candidates have to get admission through the normal selection procedure. They have to appear for the selection interview in the ECE Department of the NITC on a date decided by the Institute.
    • The candidates interested in the areas mentioned above may choose at least two topics from the titles listed below. They will be asked questions from the topics chosen by them, at the time of the interview. The questions will be such as to test basic understanding, analytical ability, creativity and academic inquisitiveness.


    • Linear Algebra
    • Functional Analysis
    • Random Process
    • Basic Signal Theory


    1) Linear Algebra

    • Kenneth Hoffman, Ray Kunze, “Linear Algebra,” PHI Learning Private Limited, 2010.
    • Gilbert Strang, "Linear Algebra and Its Applications", 3rd edn. Brooks/Cole US, 1998.

    2) Functional Analysis

    • Erwin Kreyszig, "Introductory Functional Analysis with Applications", John Wiley & Sons, 1989.

    3) Random Process

    • Peyton Z. Peebles Jr., "Probability, Random Variables and Random Signal Principles", 4th edn., Tata McGraw-Hill, New Delhi, 2002.
    • Yannis Viniotis, "Probability and Random Processes for Electrical Engineers" WCB/McGraw-Hill, 1998.

    4)  Basic Signal Theory

    • B. P. Lathi, "Linear Systems and Signals", Oxford University Press, 2002.


    • The selected research candidates, if interested to work with me in the areas mentioned above, may contact me in person to know more about the research-projects and to collect the initial reading materials.

    Ph.D. Degrees awarded:

    • Asha Vijayakumar (Design of Filter Banks Using Nilpotent Matrices)
    • Meena Vasudevan (An Information-Theoretic Approach to Sparse Representation and Recovery of Signals)
    • Gayatri Parthasarathy (Learning Algorithms for an Information-Theoretic Paradigm of Compressive Sensing)


    • Special Mention Paper Award for the paper titled: "Reconstruction of Signals From Their Blind Compressive  Measurements" IEEE 2nd International Conference on Advanced Communication Technologies and Signal Processing (ACTS) 2021. Student author: Ms. Veena Narayanan (PhD Scholar)

    Research work is basically an inquiry into the unknown. It may turn out that the original premises in a research problem were not correct. Sometimes the work might fail altogether. If the researcher does not get the support of the organization and the sponsors, the atmosphere would not be conducive to original contributions and creativity. "Safe" options in choosing research problems lead only to infinitesimal advancements. Such researchers can only be followers and never leaders. The Institution should have the courage to take up challenging problems with a lot of uncertainty and should accept occasional genuine mistakes in the process as unavoidable accompaniments of genuine research.

    - Excerpts from a printed sheet collected from a waste basket - Author unknown.

    "Nitya kaaler utshab taba
    Aami shudhu tar-i-mateer pradeep
    Jaalao tahaar shikhaa"

    -Rabindranath Tagore

    "Thine is an eternal celebration...
    A cosmic Festival of Lights..!
    Therein I am a mere flicker of a wicker lamp...
    O kindle its flame (my Master!)"

    -Translation: From the Preface of the book titled:

    "Coherent States, Wavelets and Their Generalizations"

    -Sayed Twareque Ali,
    -Jean-Pierre Antoine,
    -Jean-Pierre Gazeau.

    1) Interests:

    a) Reading (regular)(more inclined to poetry)
    b) Painting and sketching (occasional)
    c) Listening children (to learn Truth)
    d) Yoga (keeps me physically fit)