Contents
Preface
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1
Introduction
1.1 Signals, Systems, and Signal Processing
1.1.1 Basic Elements of a Digital Signal Processing System
1.1.2 Advantages of Digital over Analog Signal Processing
1.2 Classification of Signals
1.2.1 Multichannel and Multidimensional Signals
1.2.2 Continuous-Time Versus Discrete-TIme Signals
1.2.3 Continuous-Valued Versus Discrete-Valued Signals
1.2.4 Deterministic Versus Random Signals
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1.3 The Concept of Frequency in Continuous-Time and Discrete-Time Signals
1.4 Analog-to-Digital and Digital-to-Analog Conversion
1.3.1 Continuous-Time Sinusoidal Signals
1.3.2 Discrete-Time Sinusoidal Signals
1.3.3 Harmonically Related Complex Exponentials
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1.4.1 Sampling of Analog Signals
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1.4.2 The Sampling Theorem
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1.4.3 Quantization of Continuous-Amplitude Signals
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1.4.4 Quantization of Sinusoidal Signals
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1.4.5 Coding of Quantized Samples
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1.4.6 Digital-to-Analog Conversion
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1.4.7 Analysis of Digital Signals and Systems Versus Discrete-Time Signals 36
and Systems
1.5 Summary and References
Problems
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vi Contents
2 Discrete-Time Signals and Systems
2.1 Discrete-Time Signals
2.1.1 Some Elementary Discrete-Time Signals
2.1.2 Classification of Discrete-Time Signals
2.1.3 Simple Manipulations of Discrete-Time Signals
2.2 Discrete-Time Systems
Input-Output Description of Systems
2.2.1
2.2.2 Block Diagram Representation of Discrete-Time Systems
2.2.3 Classification of Discrete-Time Systems
2.2.4
Interconnection of Discrete-Time Systems
2.3 Analysis of Discrete-Time Linear Time-Invariant Systems
2.3.1 Techniques for the Analysis of Linear Systems
2.3.2 Resolution of a Discrete-Time Signal into Impulses
2.3.3 Response of LTI Systems to Arbitrary Inputs: The Convolution Sum
2.3.4 Properties of Convolution and the Interconnection of LTI Systems
2.3.5 Causal Linear Time-Invariant Systems
2.3.6 Stability of Linear Time-Invariant Systems
2.3.7 Systems with Finite-Duration and Infinite-Duration Impulse
Response
2.4 Discrete-Time Systems Described by Difference Equations
2.4.1 Recursive and Nonrecursive Discrete-Time Systems
2.4.2 Linear Time-Invariant Systems Characterized by
Constant-Coefficient Difference Equations
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2.4.3 Solution of Linear Constant-Coefficient Difference Equations
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2.4.4 The Impulse Response of a Linear Time-Invariant Recursive System 106
2.5
Implementation of Discrete-Time Systems
2.5.1 Structures for the Realization of Linear Time-Invariant Systems
2.5.2 Recursive and Nonrecursive Realizations of FIR Systems
2.6 Correlation of Discrete-Time Signals
2.6.1 Crosscorrelation and Autocorrelation Sequences
2.6.2 Properties of the Autocorrelation and Crosscorrelation Sequences
2.6.3 Correlation of Periodic Sequences
2.6.4
Input-Output Correlation Sequences
2.7 Summary and References
Problems
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3 The z -Transform and Its Application to the Analysis of L TI
Systems
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3.1 The z-Transform
3.1.1 The Direct z-Transform
3.1.2 The Inverse z-Transform
3.2 Properties of the z-Transform
3.3 Rational z-Transforms
3.3.1 Poles and Zeros
3.3.2 Pole Location and TIme-Domain Behavior for Causal Signals
3.3.3 The System Function of a Linear Time-Invariant System
3.4
Inversion of the z-Transform
3.4.1 The Inverse z-Transform by Contour Integration
3.4.2 The Inverse z-Transform by Power Series Expansion
3.4.3 The Inverse z-Transform by Partial-Fraction Expansion
3.4.4 Decomposition of Rational z-Transforms
3.5 Analysis of Linear Time-Invariant Systems in the z-Domain
3.5.1 Response of Systems with Rational System Functions
3.5.2 Transient and Steady-State Responses
3.5.3 Causality and Stability
3.5.4 Pole-Zero Cancellations
3.5.5 Multiple-Order Poles and Stability
3.5.6 Stability of Second-Order Systems
3.6 The One-sided z-Transform
3.6.1 Definition and Properties
3.6.2 Solution of Difference Equations
3.6.3 Response of Pole-Zero Systems with Nonzero Initial Conditions
3.7 Summary and References
Problems
4
Frequency Analysis of Signals
4.1 Frequency Analysis of Continuous-Time Signals
4.1.1 The Fourier Series for Continuous-TIme Periodic Signals
4.1.2 Power Density Spectrum of Periodic Signals
4.1.3 The Fourier Transform for Continuous-Time Aperiodic Signals
4.1.4 Energy Density Spectrum of Aperiodic Signals
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4.2 Frequency Analysis of Discrete-Time Signals
4.2.1 The Fourier Series for Discrete-TIme Periodic Signals
4.2.2 Power Density Spectrum of Periodic Signals
4.2.3 The fourier Transform of Discrete-TIme Aperiodic Signals
4.2.4 Convergence of the Fourier Transform
4.2.5 Energy Density Spectrum of Aperiodk Signals
4.2.6 Relationship of the Fourier Transform to the z -Transform
4.2.7 The Cepstrum
4.2.8 The Fourier Transform of Signals with Poles on the Unit Circle
4.2.9 Frequency-Domain Classification of Signals: The Concept of
Bandwidth
4.2.10 The Frequency Ranges of Some Natural Signals
4.3 Frequency-Domain and Time-Domain Signal Properties
4.4 Properties of the Fourier Transform for Discrete-Time Signals
4.4.1 Symmetry Properties of the Fourier Transform
4.4.2 Fourier Transform Theorems and Properties
4.5 Summary and References
Problems
5
Frequency-Domain Analysis of LTI Systems
5.1 Frequency-Domain Characteristics of Linear TIme-Invariant Systems
5.1.1 Response to Complex Exponential and Sinusoidal Signals: The
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5.3 Correlation Functions and Spectra at the Output of LTI Systems
Input-Output Correlation Functions and Spectra
Frequency Response Function
5.1.2 Steady-State and Transient Response to Sinusoidal Input Signals
5.1.3 Steady-State Response to Periodic Input Signals
5.1.4 Response to Aperiodic Input Signals
5.2.1 Frequency Response of a System with a Rational System Function
5.2.2 Computation of the Frequency Response Function
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5.3.1
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5.3.2 Correlation Functions and Power Spectra for Random Input Signals 323
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5.4.1
5.4.2 Lowpass, Highpass, and Bandpass Filters
5.4.3 Digital Resonators
5.4.4 Notch Filters
5.4.5 Comb Filters
5.2 Frequency Response of LTI Systems
5.4 Linear Time-Invariant Systems as Frequency-Selective Filters
Ideal Filter Characteristics