The objective of this book is to provide an introduction to the basic principles in the analysis and design
of communication systems. It is primarily intended for use as a text for a first course in communications, either
at a senior level or at a first-year graduate level.
BROAD TOPICAL COVERAGE
Although we have placed a very strong emphasis on digital communications, we have provided a review of important
mathematical foundational topics and a solid introduction to analog communications. The major topics covered are:
A review of frequency domain analysis of signals and systems, and the characterization of random processes
(Chapters 2 and 4)
An introduction to analog signal transmission and reception (Chapters 3 and 5)
An introduction to digital communications (Chapters 6-10)
EMPHASIS ON DIGITAL COMMUNICATIONS
Our motivation for emphasizing digital communications is due to the technological developments that have occurred
during the past five decades. Today, digital communication systems are in common use and generally carry the bulk
of our daily information transmission through a variety of communications media, such as wireline telephone channels,
microwave radio, fiber optic channels, and satellite channels. We are currently witnessing an explosive growth
in the development of personal communication systems and ultrahigh speed communication networks, which are based
on digital transmission of the information, whether it is voice, still images, or video. We anticipate that, in
the near future, we will witness a replacement of the current analog AM and FM radio and television broadcast by
digital transmission systems.
The development of sophisticated, high-speed digital communication systems has been accelerated by concurrent
developments in inexpensive high speed integrated circuits (IC) and programmable digital signal processing chips.
The developments in Microelectronic IC fabrication have made possible the implementation of high-speed, high precision
A/D converters, of powerful error-correcting coders/decoders, and of complex digital modulation techniques. All
of these technological developments point to a continuation in the trend toward increased use of digital communications
as a means for transmitting information.
OVERVIEW OF THE TEXT
It is assumed that students using this book have a basic understanding of linear system theory, both continuous
and discrete, including a working knowledge of Fourier series and Fourier transform techniques. Chapter 2 provides
a review of basic material on signals and systems and establishes the necessary notation used in subsequent chapters.
It is also assumed that students have had a first course in probability. Such courses are currently required in
many undergraduate electrical engineering and computer engineering programs. Chapter 4 provides a review of probability
and random processes to the extent that is necessary for a first course in communications.
Chapter 3 treats modulation and demodulation of analog signals. This treatment includes amplitude modulation
(AM), frequency modulation (FM), and phase modulation (PM). Radio and television broadcasting and mobile
radio cellular systems are discussed as examples of analog communication systems. Chapter 5 continues the treatment
of analog communication systems by analyzing the effect of additive noise in the demodulation of AM, FM, and PM
signals. The phase-locked loop, which is used for estimating the phase of a sinusoidal carrier in both analog and
digital communication systems is also described in Chapter 5. The chapter concludes with a treatment of the effect
of transmission losses and the characterization of noise sources in communication systems.
A logical beginning in the introduction of digital communication systems analysis and design is the characterization
of information sources and source encoding. Chapter 6 is devoted to this topic. In this chapter we introduce the
reader to the modeling of information sources, both discrete and continuous (analog), and the basic mathematical
concepts of entropy and mutual information. Our discussion of source encoding for discrete sources includes the
Huffman coding algorithm and the Lempel-Ziv algorithm. For the case of analog sources, we treat both scalar and
vector quantization and describe the common waveform-coding techniques, namely, PCM, DPCM, and DM. We also describe
the LPC-based source modeling method. As practical examples of the sourcecoding methods described in this chapter
we cite the digital speech transmission systems in the telephone plant, the digital audio recording systems as
embodied in the compact disc (CD) player and the JPEG image-coding standard.
Digital modulation and demodulation techniques are described in Chapter 7. Binary and nonbinary modulation methods
are described based on a geometric representation of signals, and their error-rate performance is evaluated and
compared. This chapter also describes symbol synchronization methods for digital communication systems.
Chapter 8 treats digital transmission through bandlimited AWGN channels. In this chapter we derive the power-spectral
density of linearly modulated baseband signals and consider the problem of signal design for a bandlimited channel.
We show that the effect of channel distortion is to introduce intersymbol interference (ISI), which can be eliminated
or minimized by proper signal design. The use of linear and nonlinear adaptive equalizers for reducing the effect
of ISI is also described.
Chapter 9 treats the topic of channel coding and decoding. The capacity of a communication channel is first
defined, and the capacity of the Gaussian channel is determined. Linear block codes and convolutional codes are
introduced and appropriate decoding algorithms are described. The benefits of coding for bandwidth constrained
channels are also described. The final section of this chapter presents three practical applications of coding.
The last chapter of this book treats topics in wireless communications. First, we consider the characterization
of fading multipath channels and describe the effects of such channels on wireless digital communication systems.
The design of signals that are effective in mitigating this type of channel distortion is also considered. Second,
we describe the class of continuous-phase modulated signals, which are especially suitable for digital communication
in wireless channels. Finally, we treat the class of spreadspectrum signals, which are suitable for mufti-user
wireless communication systems.
EXAMPLES AND HOMEWORK PROBLEMS
We have included a large number of carefully chosen examples and homework problems. The text contains over 180
worked-out examples and over 480 problems. Examples and problems range from simple exercises to more challenging
and thought-provoking problems. A Solutions Manual is available free to all adopting faculty, which is provided
in both typeset form and as a diskette formatted in LATEX. Solutions are not available for sale to students. This
will enable instructors to print out solutions in any configuration easily.
COURSE OPTIONS
This book can serve as a text in either a one- or two-semester course in communication system. An important
consideration in the design of the course is whether or not the students have had a prior course in probability
and random processes. Another important consideration is whether or not analog modulation and demodulation techniques
are to be covered. Here, we outline three scenarios. Others are certainly possible.
A one-term course in analog and digital communication: Selected review sections from Chapters 2 and 4, all
of chapters 3, 5, 7, and 8, and selections from chapters 6, 9, and 10.
A one-term course in digital communication: Selected review sections from Chapters 2 and 4, and Chapters 6-10.
A two-term course sequence on analog and digital communications: (a) Chapters 2-6 for the first course. (b) Chapters 7-10 for the second course.
We wish to thank Gloria Doukakis for her assistance in the preparation of the...
Summary
For a one/two-semester senior or first-year graduate level course in analog and digital communications.
With an emphasis on digital communications, Communication Systems Engineering, Second Edition introduces the basic
principles underlying the analysis and design of communication systems. In addition, this text gives a solid introduction
to analog communications and a review of important mathematical foundation topics.
Features:
NEW�New material has been added on wireless communication systems�GSM and CDMA/IS-94; turbo codes and iterative
decoding; multicarrier (OFDM) systems; multiple antenna systems.
Provides students with timely and current information.
Thorough coverage of basic digital communication system principles�Including source coding, channel coding,
baseband and carrier modulation, channel distortion, channel equalization, synchronization, and wireless communications.
Ensures that students are exposed to all basic relevant topics in digital communication system design.
Basic coverage of analog modulation and demodulation methods.
Exposes students to analog modulation methods such as amplitude modulation, phase modulation, and frequency
modulation.
Use of CD player and JPEG image coding standard as examples of systems that employ modern communication principles.
Allows students to relate the theory to practical systems.
Over 180 worked-out examples throughout the text.
Helps students understand basic concepts.
Over 480 problems�Involving applications to practical systems such as satellite communications systems, ionospheric
channels, and mobile radio channels.
Gives students ample opportunity to practice the concepts they have just learned. Gives instructors a wide
variety of options when assigning homework.
Table of Contents
(NOTE: Each chapter concludes with Further Reading and Problems.)
1. Introduction
Historical Review
Elements of an Electrical Communication System
Communication Channels and Their Characteristics
Mathematical Models for Communication Channels
Organization of the Book
2. Frequency Domain Analysis of Signals and Systems
Fourier Series
Fourier Transforms
Power and Energy
Sampling of Bandlimited Signals
Bandpass Signals
3. Analog Signal Transmission and Reception
Introduction to Modulation
Amplitude Modulation (AM)
Angle Modulation
Radio and Television Broadcasting
Mobile Radio Stations
4. Random Processes
Probability and Random Variables
Random Processes: Basic Concepts
Random Processes in the Frequency Domain
Gaussian and White Processes
Bandlimited Processes and Sampling
Bandpass Processes
5. Effect of Noise on Analog Communication Systems
Effect of Noise on Linear Modulation Systems
Carrier Phase Estimation with a Phase-Locked Loop (PLL)
Effect of Noise on Angle Modulation
Comparison of Analog Modulation Systems
Effects of Transmission Losses and Noise in Analog Communication Systems
6. Information Sources and Source Coding
Modeling of Information Sources
Source Coding Theorem
Source Coding Algorithms
Rate-Distortion Theory
Quantization
Waveform Coding
Analysis-Synthesis Techniques
Digital Audio Transmission and Digital Audio Recording
The JPEG Image Coding Standard
7. Digital Transmission through the Additive White Gaussian Noise Channel
Geometric Representation of Signal Waveforms
Pulse Amplitude Modulation
Two-Dimensional Signal Waveforms
Multidimensional Signal Waveforms
Optimum Receiver for Digitally Modulated Signals in Additive White Gaussian Noise
Probability of Error for Signal Detection in Additive White Gaussian Noise
Performance Analysis for Wireline and Radio Communication Channels
Symbol Synchronization
8. Digital Transmission through Bandlimited AWGN Channels
Digital Transmission through Bandlimited Channels
The Power Spectrum of Digitally Modulated Signals
Signal Design for Bandlimited Channels
Probability of Error in Detection of Digital PAM
Digitally Modulated Signals with Memory
System Design in the Presence of Channel Distortion
Multicarrier Modulation and OFDM
9. Channel Capacity and Coding
Modeling of Communication Channels
Channel Capacity
Bounds on Communication
Coding for Reliable Communication
Linear Block Codes
Cyclic Codes
Convolutional Codes
Complex Codes Based on Combination of Simple Codes
Coding for Bandwidth Constrained Channels
Practical Applications of Coding
10. Wireless Communications
Digital Transmission on Fading Multipath Channels
Continuous Carrier Phase Modulation
Spread Spectrum Communication Systems
Digital Cellular Communication Systems