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EE627 - Speech Signal Processing Lecture 3/4 : Basic Signal Processing ...home.iitk.ac.in/~rhegde/ee627_2018/lec_3.4.pdf · Developing a Complete Digital Speech Model EE627 - Speech

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Page 1: EE627 - Speech Signal Processing Lecture 3/4 : Basic Signal Processing ...home.iitk.ac.in/~rhegde/ee627_2018/lec_3.4.pdf · Developing a Complete Digital Speech Model EE627 - Speech

OverviewDiscrete Time Sequences

Properties of Discrete Time SystemsThe Discrete Time Fourier Transform and its Properties

The Z - Transform and ROCModeling Speech with the Transfer Function and Di�erence Equations

Developing a Complete Digital Speech Model

EE627 - Speech Signal ProcessingLecture 3/4 : Basic Signal Processing Techniques

for Speech Recognition

R. Hegde

Dept. of Electrical Engg.

IIT Kanpur

rhegde@ iitk.ac.in EE627 - Speech Signal Processing, Lecture 3/4

Page 2: EE627 - Speech Signal Processing Lecture 3/4 : Basic Signal Processing ...home.iitk.ac.in/~rhegde/ee627_2018/lec_3.4.pdf · Developing a Complete Digital Speech Model EE627 - Speech

OverviewDiscrete Time Sequences

Properties of Discrete Time SystemsThe Discrete Time Fourier Transform and its Properties

The Z - Transform and ROCModeling Speech with the Transfer Function and Di�erence Equations

Developing a Complete Digital Speech Model

Outline

1 Overview

2 Discrete Time Sequences

3 Properties of Discrete Time Systems

4 The Discrete Time Fourier Transform and its Properties

5 The Z - Transform and ROC

6 Modeling Speech with the Transfer Function and Di�erence

Equations

7 Developing a Complete Digital Speech Model

rhegde@ iitk.ac.in EE627 - Speech Signal Processing, Lecture 3/4

Page 3: EE627 - Speech Signal Processing Lecture 3/4 : Basic Signal Processing ...home.iitk.ac.in/~rhegde/ee627_2018/lec_3.4.pdf · Developing a Complete Digital Speech Model EE627 - Speech

OverviewDiscrete Time Sequences

Properties of Discrete Time SystemsThe Discrete Time Fourier Transform and its Properties

The Z - Transform and ROCModeling Speech with the Transfer Function and Di�erence Equations

Developing a Complete Digital Speech Model

Basic Problem

Overview of Digital Speech

rhegde@ iitk.ac.in EE627 - Speech Signal Processing, Lecture 3/4

Page 4: EE627 - Speech Signal Processing Lecture 3/4 : Basic Signal Processing ...home.iitk.ac.in/~rhegde/ee627_2018/lec_3.4.pdf · Developing a Complete Digital Speech Model EE627 - Speech

OverviewDiscrete Time Sequences

Properties of Discrete Time SystemsThe Discrete Time Fourier Transform and its Properties

The Z - Transform and ROCModeling Speech with the Transfer Function and Di�erence Equations

Developing a Complete Digital Speech Model

Discrete Time Sequences

rhegde@ iitk.ac.in EE627 - Speech Signal Processing, Lecture 3/4

Page 5: EE627 - Speech Signal Processing Lecture 3/4 : Basic Signal Processing ...home.iitk.ac.in/~rhegde/ee627_2018/lec_3.4.pdf · Developing a Complete Digital Speech Model EE627 - Speech

OverviewDiscrete Time Sequences

Properties of Discrete Time SystemsThe Discrete Time Fourier Transform and its Properties

The Z - Transform and ROCModeling Speech with the Transfer Function and Di�erence Equations

Developing a Complete Digital Speech Model

The Complex Exponential Sequence

rhegde@ iitk.ac.in EE627 - Speech Signal Processing, Lecture 3/4

Page 6: EE627 - Speech Signal Processing Lecture 3/4 : Basic Signal Processing ...home.iitk.ac.in/~rhegde/ee627_2018/lec_3.4.pdf · Developing a Complete Digital Speech Model EE627 - Speech

OverviewDiscrete Time Sequences

Properties of Discrete Time SystemsThe Discrete Time Fourier Transform and its Properties

The Z - Transform and ROCModeling Speech with the Transfer Function and Di�erence Equations

Developing a Complete Digital Speech Model

Discrete Time Systems

rhegde@ iitk.ac.in EE627 - Speech Signal Processing, Lecture 3/4

Page 7: EE627 - Speech Signal Processing Lecture 3/4 : Basic Signal Processing ...home.iitk.ac.in/~rhegde/ee627_2018/lec_3.4.pdf · Developing a Complete Digital Speech Model EE627 - Speech

OverviewDiscrete Time Sequences

Properties of Discrete Time SystemsThe Discrete Time Fourier Transform and its Properties

The Z - Transform and ROCModeling Speech with the Transfer Function and Di�erence Equations

Developing a Complete Digital Speech Model

Linear Discrete Time Invariant Systems

rhegde@ iitk.ac.in EE627 - Speech Signal Processing, Lecture 3/4

Page 8: EE627 - Speech Signal Processing Lecture 3/4 : Basic Signal Processing ...home.iitk.ac.in/~rhegde/ee627_2018/lec_3.4.pdf · Developing a Complete Digital Speech Model EE627 - Speech

OverviewDiscrete Time Sequences

Properties of Discrete Time SystemsThe Discrete Time Fourier Transform and its Properties

The Z - Transform and ROCModeling Speech with the Transfer Function and Di�erence Equations

Developing a Complete Digital Speech Model

Convolution and Speech Processing

rhegde@ iitk.ac.in EE627 - Speech Signal Processing, Lecture 3/4

Page 9: EE627 - Speech Signal Processing Lecture 3/4 : Basic Signal Processing ...home.iitk.ac.in/~rhegde/ee627_2018/lec_3.4.pdf · Developing a Complete Digital Speech Model EE627 - Speech

OverviewDiscrete Time Sequences

Properties of Discrete Time SystemsThe Discrete Time Fourier Transform and its Properties

The Z - Transform and ROCModeling Speech with the Transfer Function and Di�erence Equations

Developing a Complete Digital Speech Model

Stability and Causality

rhegde@ iitk.ac.in EE627 - Speech Signal Processing, Lecture 3/4

Page 10: EE627 - Speech Signal Processing Lecture 3/4 : Basic Signal Processing ...home.iitk.ac.in/~rhegde/ee627_2018/lec_3.4.pdf · Developing a Complete Digital Speech Model EE627 - Speech

OverviewDiscrete Time Sequences

Properties of Discrete Time SystemsThe Discrete Time Fourier Transform and its Properties

The Z - Transform and ROCModeling Speech with the Transfer Function and Di�erence Equations

Developing a Complete Digital Speech Model

Stability and Causality : An Example

rhegde@ iitk.ac.in EE627 - Speech Signal Processing, Lecture 3/4

Page 11: EE627 - Speech Signal Processing Lecture 3/4 : Basic Signal Processing ...home.iitk.ac.in/~rhegde/ee627_2018/lec_3.4.pdf · Developing a Complete Digital Speech Model EE627 - Speech

OverviewDiscrete Time Sequences

Properties of Discrete Time SystemsThe Discrete Time Fourier Transform and its Properties

The Z - Transform and ROCModeling Speech with the Transfer Function and Di�erence Equations

Developing a Complete Digital Speech Model

The DTFT Pair

rhegde@ iitk.ac.in EE627 - Speech Signal Processing, Lecture 3/4

Page 12: EE627 - Speech Signal Processing Lecture 3/4 : Basic Signal Processing ...home.iitk.ac.in/~rhegde/ee627_2018/lec_3.4.pdf · Developing a Complete Digital Speech Model EE627 - Speech

OverviewDiscrete Time Sequences

Properties of Discrete Time SystemsThe Discrete Time Fourier Transform and its Properties

The Z - Transform and ROCModeling Speech with the Transfer Function and Di�erence Equations

Developing a Complete Digital Speech Model

Properties of DTFT relevant to Speech Recognition

rhegde@ iitk.ac.in EE627 - Speech Signal Processing, Lecture 3/4

Page 13: EE627 - Speech Signal Processing Lecture 3/4 : Basic Signal Processing ...home.iitk.ac.in/~rhegde/ee627_2018/lec_3.4.pdf · Developing a Complete Digital Speech Model EE627 - Speech

OverviewDiscrete Time Sequences

Properties of Discrete Time SystemsThe Discrete Time Fourier Transform and its Properties

The Z - Transform and ROCModeling Speech with the Transfer Function and Di�erence Equations

Developing a Complete Digital Speech Model

Energy Density of a Signal

rhegde@ iitk.ac.in EE627 - Speech Signal Processing, Lecture 3/4

Page 14: EE627 - Speech Signal Processing Lecture 3/4 : Basic Signal Processing ...home.iitk.ac.in/~rhegde/ee627_2018/lec_3.4.pdf · Developing a Complete Digital Speech Model EE627 - Speech

OverviewDiscrete Time Sequences

Properties of Discrete Time SystemsThe Discrete Time Fourier Transform and its Properties

The Z - Transform and ROCModeling Speech with the Transfer Function and Di�erence Equations

Developing a Complete Digital Speech Model

DTFT of Single and Multiple Exponential and Sinusoidalsequences

rhegde@ iitk.ac.in EE627 - Speech Signal Processing, Lecture 3/4

Page 15: EE627 - Speech Signal Processing Lecture 3/4 : Basic Signal Processing ...home.iitk.ac.in/~rhegde/ee627_2018/lec_3.4.pdf · Developing a Complete Digital Speech Model EE627 - Speech

OverviewDiscrete Time Sequences

Properties of Discrete Time SystemsThe Discrete Time Fourier Transform and its Properties

The Z - Transform and ROCModeling Speech with the Transfer Function and Di�erence Equations

Developing a Complete Digital Speech Model

Important Generalizations

rhegde@ iitk.ac.in EE627 - Speech Signal Processing, Lecture 3/4

Page 16: EE627 - Speech Signal Processing Lecture 3/4 : Basic Signal Processing ...home.iitk.ac.in/~rhegde/ee627_2018/lec_3.4.pdf · Developing a Complete Digital Speech Model EE627 - Speech

OverviewDiscrete Time Sequences

Properties of Discrete Time SystemsThe Discrete Time Fourier Transform and its Properties

The Z - Transform and ROCModeling Speech with the Transfer Function and Di�erence Equations

Developing a Complete Digital Speech Model

The Z - Transform

rhegde@ iitk.ac.in EE627 - Speech Signal Processing, Lecture 3/4

Page 17: EE627 - Speech Signal Processing Lecture 3/4 : Basic Signal Processing ...home.iitk.ac.in/~rhegde/ee627_2018/lec_3.4.pdf · Developing a Complete Digital Speech Model EE627 - Speech

OverviewDiscrete Time Sequences

Properties of Discrete Time SystemsThe Discrete Time Fourier Transform and its Properties

The Z - Transform and ROCModeling Speech with the Transfer Function and Di�erence Equations

Developing a Complete Digital Speech Model

The IZT and ROC

rhegde@ iitk.ac.in EE627 - Speech Signal Processing, Lecture 3/4

Page 18: EE627 - Speech Signal Processing Lecture 3/4 : Basic Signal Processing ...home.iitk.ac.in/~rhegde/ee627_2018/lec_3.4.pdf · Developing a Complete Digital Speech Model EE627 - Speech

OverviewDiscrete Time Sequences

Properties of Discrete Time SystemsThe Discrete Time Fourier Transform and its Properties

The Z - Transform and ROCModeling Speech with the Transfer Function and Di�erence Equations

Developing a Complete Digital Speech Model

The ROC for Four Typical Sequences

rhegde@ iitk.ac.in EE627 - Speech Signal Processing, Lecture 3/4

Page 19: EE627 - Speech Signal Processing Lecture 3/4 : Basic Signal Processing ...home.iitk.ac.in/~rhegde/ee627_2018/lec_3.4.pdf · Developing a Complete Digital Speech Model EE627 - Speech

OverviewDiscrete Time Sequences

Properties of Discrete Time SystemsThe Discrete Time Fourier Transform and its Properties

The Z - Transform and ROCModeling Speech with the Transfer Function and Di�erence Equations

Developing a Complete Digital Speech Model

The ROC - Contd.

rhegde@ iitk.ac.in EE627 - Speech Signal Processing, Lecture 3/4

Page 20: EE627 - Speech Signal Processing Lecture 3/4 : Basic Signal Processing ...home.iitk.ac.in/~rhegde/ee627_2018/lec_3.4.pdf · Developing a Complete Digital Speech Model EE627 - Speech

OverviewDiscrete Time Sequences

Properties of Discrete Time SystemsThe Discrete Time Fourier Transform and its Properties

The Z - Transform and ROCModeling Speech with the Transfer Function and Di�erence Equations

Developing a Complete Digital Speech Model

Transfer Function of LTI Systems

rhegde@ iitk.ac.in EE627 - Speech Signal Processing, Lecture 3/4

Page 21: EE627 - Speech Signal Processing Lecture 3/4 : Basic Signal Processing ...home.iitk.ac.in/~rhegde/ee627_2018/lec_3.4.pdf · Developing a Complete Digital Speech Model EE627 - Speech

OverviewDiscrete Time Sequences

Properties of Discrete Time SystemsThe Discrete Time Fourier Transform and its Properties

The Z - Transform and ROCModeling Speech with the Transfer Function and Di�erence Equations

Developing a Complete Digital Speech Model

Convolution and Windowing Theoroem

rhegde@ iitk.ac.in EE627 - Speech Signal Processing, Lecture 3/4

Page 22: EE627 - Speech Signal Processing Lecture 3/4 : Basic Signal Processing ...home.iitk.ac.in/~rhegde/ee627_2018/lec_3.4.pdf · Developing a Complete Digital Speech Model EE627 - Speech

OverviewDiscrete Time Sequences

Properties of Discrete Time SystemsThe Discrete Time Fourier Transform and its Properties

The Z - Transform and ROCModeling Speech with the Transfer Function and Di�erence Equations

Developing a Complete Digital Speech Model

Relating the Transfer Function and the Spectral Envelope

rhegde@ iitk.ac.in EE627 - Speech Signal Processing, Lecture 3/4

Page 23: EE627 - Speech Signal Processing Lecture 3/4 : Basic Signal Processing ...home.iitk.ac.in/~rhegde/ee627_2018/lec_3.4.pdf · Developing a Complete Digital Speech Model EE627 - Speech

OverviewDiscrete Time Sequences

Properties of Discrete Time SystemsThe Discrete Time Fourier Transform and its Properties

The Z - Transform and ROCModeling Speech with the Transfer Function and Di�erence Equations

Developing a Complete Digital Speech Model

Relating the Transfer Function and the Spectral Envelope -Contd.

rhegde@ iitk.ac.in EE627 - Speech Signal Processing, Lecture 3/4

Page 24: EE627 - Speech Signal Processing Lecture 3/4 : Basic Signal Processing ...home.iitk.ac.in/~rhegde/ee627_2018/lec_3.4.pdf · Developing a Complete Digital Speech Model EE627 - Speech

OverviewDiscrete Time Sequences

Properties of Discrete Time SystemsThe Discrete Time Fourier Transform and its Properties

The Z - Transform and ROCModeling Speech with the Transfer Function and Di�erence Equations

Developing a Complete Digital Speech Model

The Constant Co-e�cient Linear Di�erence Equation

rhegde@ iitk.ac.in EE627 - Speech Signal Processing, Lecture 3/4

Page 25: EE627 - Speech Signal Processing Lecture 3/4 : Basic Signal Processing ...home.iitk.ac.in/~rhegde/ee627_2018/lec_3.4.pdf · Developing a Complete Digital Speech Model EE627 - Speech

OverviewDiscrete Time Sequences

Properties of Discrete Time SystemsThe Discrete Time Fourier Transform and its Properties

The Z - Transform and ROCModeling Speech with the Transfer Function and Di�erence Equations

Developing a Complete Digital Speech Model

Pole Zero concepts from the CCLDE

rhegde@ iitk.ac.in EE627 - Speech Signal Processing, Lecture 3/4

Page 26: EE627 - Speech Signal Processing Lecture 3/4 : Basic Signal Processing ...home.iitk.ac.in/~rhegde/ee627_2018/lec_3.4.pdf · Developing a Complete Digital Speech Model EE627 - Speech

OverviewDiscrete Time Sequences

Properties of Discrete Time SystemsThe Discrete Time Fourier Transform and its Properties

The Z - Transform and ROCModeling Speech with the Transfer Function and Di�erence Equations

Developing a Complete Digital Speech Model

Speech Models as Linear Time Varying Systems

rhegde@ iitk.ac.in EE627 - Speech Signal Processing, Lecture 3/4

Page 27: EE627 - Speech Signal Processing Lecture 3/4 : Basic Signal Processing ...home.iitk.ac.in/~rhegde/ee627_2018/lec_3.4.pdf · Developing a Complete Digital Speech Model EE627 - Speech

OverviewDiscrete Time Sequences

Properties of Discrete Time SystemsThe Discrete Time Fourier Transform and its Properties

The Z - Transform and ROCModeling Speech with the Transfer Function and Di�erence Equations

Developing a Complete Digital Speech Model

The Discrete Fourier Transform (DFT)

rhegde@ iitk.ac.in EE627 - Speech Signal Processing, Lecture 3/4

Page 28: EE627 - Speech Signal Processing Lecture 3/4 : Basic Signal Processing ...home.iitk.ac.in/~rhegde/ee627_2018/lec_3.4.pdf · Developing a Complete Digital Speech Model EE627 - Speech

OverviewDiscrete Time Sequences

Properties of Discrete Time SystemsThe Discrete Time Fourier Transform and its Properties

The Z - Transform and ROCModeling Speech with the Transfer Function and Di�erence Equations

Developing a Complete Digital Speech Model

Sampling and Reconstruction of the Speech Signal

rhegde@ iitk.ac.in EE627 - Speech Signal Processing, Lecture 3/4

Page 29: EE627 - Speech Signal Processing Lecture 3/4 : Basic Signal Processing ...home.iitk.ac.in/~rhegde/ee627_2018/lec_3.4.pdf · Developing a Complete Digital Speech Model EE627 - Speech

OverviewDiscrete Time Sequences

Properties of Discrete Time SystemsThe Discrete Time Fourier Transform and its Properties

The Z - Transform and ROCModeling Speech with the Transfer Function and Di�erence Equations

Developing a Complete Digital Speech Model

Sampling the Impulse Response

rhegde@ iitk.ac.in EE627 - Speech Signal Processing, Lecture 3/4

Page 30: EE627 - Speech Signal Processing Lecture 3/4 : Basic Signal Processing ...home.iitk.ac.in/~rhegde/ee627_2018/lec_3.4.pdf · Developing a Complete Digital Speech Model EE627 - Speech

OverviewDiscrete Time Sequences

Properties of Discrete Time SystemsThe Discrete Time Fourier Transform and its Properties

The Z - Transform and ROCModeling Speech with the Transfer Function and Di�erence Equations

Developing a Complete Digital Speech Model

Pole Zero Modeling the Vocal Tract

rhegde@ iitk.ac.in EE627 - Speech Signal Processing, Lecture 3/4

Page 31: EE627 - Speech Signal Processing Lecture 3/4 : Basic Signal Processing ...home.iitk.ac.in/~rhegde/ee627_2018/lec_3.4.pdf · Developing a Complete Digital Speech Model EE627 - Speech

OverviewDiscrete Time Sequences

Properties of Discrete Time SystemsThe Discrete Time Fourier Transform and its Properties

The Z - Transform and ROCModeling Speech with the Transfer Function and Di�erence Equations

Developing a Complete Digital Speech Model

Developing a Digital Model for Speech Production : VocalTract

rhegde@ iitk.ac.in EE627 - Speech Signal Processing, Lecture 3/4

Page 32: EE627 - Speech Signal Processing Lecture 3/4 : Basic Signal Processing ...home.iitk.ac.in/~rhegde/ee627_2018/lec_3.4.pdf · Developing a Complete Digital Speech Model EE627 - Speech

OverviewDiscrete Time Sequences

Properties of Discrete Time SystemsThe Discrete Time Fourier Transform and its Properties

The Z - Transform and ROCModeling Speech with the Transfer Function and Di�erence Equations

Developing a Complete Digital Speech Model

Developing a Digital Model for Speech Production : All Polemodeling the Tract

rhegde@ iitk.ac.in EE627 - Speech Signal Processing, Lecture 3/4

Page 33: EE627 - Speech Signal Processing Lecture 3/4 : Basic Signal Processing ...home.iitk.ac.in/~rhegde/ee627_2018/lec_3.4.pdf · Developing a Complete Digital Speech Model EE627 - Speech

OverviewDiscrete Time Sequences

Properties of Discrete Time SystemsThe Discrete Time Fourier Transform and its Properties

The Z - Transform and ROCModeling Speech with the Transfer Function and Di�erence Equations

Developing a Complete Digital Speech Model

Developing a Digital Model for Speech Production : VT +Lip radiation

rhegde@ iitk.ac.in EE627 - Speech Signal Processing, Lecture 3/4

Page 34: EE627 - Speech Signal Processing Lecture 3/4 : Basic Signal Processing ...home.iitk.ac.in/~rhegde/ee627_2018/lec_3.4.pdf · Developing a Complete Digital Speech Model EE627 - Speech

OverviewDiscrete Time Sequences

Properties of Discrete Time SystemsThe Discrete Time Fourier Transform and its Properties

The Z - Transform and ROCModeling Speech with the Transfer Function and Di�erence Equations

Developing a Complete Digital Speech Model

Developing a Digital Model for Speech Production : TheComplete Model

rhegde@ iitk.ac.in EE627 - Speech Signal Processing, Lecture 3/4

Page 35: EE627 - Speech Signal Processing Lecture 3/4 : Basic Signal Processing ...home.iitk.ac.in/~rhegde/ee627_2018/lec_3.4.pdf · Developing a Complete Digital Speech Model EE627 - Speech

OverviewDiscrete Time Sequences

Properties of Discrete Time SystemsThe Discrete Time Fourier Transform and its Properties

The Z - Transform and ROCModeling Speech with the Transfer Function and Di�erence Equations

Developing a Complete Digital Speech Model

References

Rabiner and Juang , Fundamentals of Speech Recognition,

Prentice Hall

T. Quatieri, Discrete Time Speech Signal Processing , Prentice

Hall

Rabiner and Schafer, Discrete Time Processing of Speech

Signals , Prentice Hall

rhegde@ iitk.ac.in EE627 - Speech Signal Processing, Lecture 3/4