Wireless Communications Principles and Practice

by Rappaport, Theodore S.

• ISBN13: 9780130422323
• ISBN10: 0130422320
• Edition: 2nd
• Format: Hardcover
• Copyright: 2001-12-31
• Publisher: Prentice Hall

Summary

Wireless Communications, Second Editionis the definitive professional's overview of wireless communications technology and system design. Building on his classic first edition, Theodore S. Rappaport reviews virtually every important new wireless standard and technological development, including W-CDMA, cdma2000, UMTS, and UMC 136/EDGE; IEEE 802.11 and HIPERLAN WLANs; Bluetooth, LMDS, and more. Includes dozens of practical new examples, solved step by step.

Author Biography

Theodore S. Rappaport is the James S. Tucker Professor of Electrical and Computer Engineering at the Virginia Polytechnic Institute and State University and the Series Editor for Prentice Hall's Communications Engineering and Emerging Technologies Series

Table of Contents

Preface	xix
Introduction to Wireless Communication Systems	1	(24)
Evolution of Mobile Radio Communications	1	(3)
Mobile Radiotelephony in the U.S.	4	(2)
Mobile Radio Systems Around the World	6	(3)
Examples of Wireless Communication Systems	9	(11)
Paging Systems	11	(1)
Cordless Telephone Systems	12	(1)
Cellular Telephone Systems	13	(2)
How a Cellular Telephone Call is Made	15	(3)
Comparison of Common Wireless Communication Systems	18	(2)
Trends in Cellular Radio and Personal Communications	20	(2)
Problems	22	(3)
Modern Wireless Communication Systems	25	(32)
Second Generation (2G) Cellular Networks	26	(8)
Evolution to 2.5G Wireless Networks	29	(1)
Evolution for 2.5G TDMA Standards	30	(1)
HSCSD for 2.5G GSM	30	(1)
GPRS for 2.5G GSM and IS-136	31	(2)
EDGE for 2.5G GSM and IS-136	33	(1)
IS-95B for 2.5G CDMA	34	(1)
Third Generation (3G) Wireless Networks	34	(6)
3G W-CDMA (UMTS)	37	(1)
3G cdma2000	38	(1)
3G TD-SCDMA	39	(1)
Wireless Local Loop (WLL) and LMDS	40	(6)
Wireless Local Area Networks (WLANs)	46	(6)
Bluetooth and Personal Area Networks (PANs)	52	(2)
Summary	54	(1)
Problems	55	(2)
The Cellular Concept-System Design Fundamentals	57	(48)
Introduction	57	(1)
Frequency Reuse	58	(4)
Channel Assignment Strategies	62	(1)
Handoff Strategies	62	(5)
Prioritizing Handoffs	65	(1)
Practical Handoff Considerations	66	(1)
Interference and System Capacity	67	(10)
Co-channel Interference and System Capacity	68	(4)
Channel Planning for Wireless Systems	72	(2)
Adjacent Channel Interference	74	(2)
Power Control for Reducing Interference	76	(1)
Trunking and Grade of Service	77	(9)
Improving Coverage & Capacity in Cellular Systems	86	(10)
Cell Splitting	86	(4)
Sectoring	90	(3)
Repeaters for Range Extension	93	(1)
A Microcell Zone Concept	93	(3)
Summary	96	(1)
Problems	97	(8)
Mobile Radio Propagation: Large-Scale Path Loss	105	(72)
Introduction to Radio Wave Propagation	105	(2)
Free Space Propagation Model	107	(3)
Relating Power to Electric Field	110	(3)
The Three Basic Propagation Mechanisms	113	(1)
Reflection	114	(6)
Reflection from Dielectrics	114	(5)
Brewster Angle	119	(1)
Reflection from Perfect Conductors	120	(1)
Ground Reflection (Two-Ray) Model	120	(6)
Diffraction	126	(9)
Fresnel Zone Geometry	126	(3)
Knife-edge Diffraction Model	129	(5)
Multiple Knife-edge Diffraction	134	(1)
Scattering	135	(3)
Radar Cross Section Model	136	(2)
Practical Link Budget Design Using Path Loss Models	138	(7)
Log-distance Path Loss Model	138	(1)
Log-normal Shadowing	139	(2)
Determination of Percentage of Coverage Area	141	(4)
Outdoor Propagation Models	145	(12)
Longley-Rice Model	145	(1)
Durkin's Model-A Case Study	146	(4)
Okumura Model	150	(3)
Hata Model	153	(1)
PCS Extension to Hata Model	154	(1)
Walfisch and Bertoni Model	155	(1)
Wideband PCS Microcell Model	155	(2)
Indoor Propagation Models	157	(9)
Partition Losses (same floor)	157	(3)
Partition Losses between Floors	160	(1)
Log-distance Path Loss Model	161	(1)
Ericsson Multiple Breakpoint Model	161	(2)
Attenuation Factor Model	163	(3)
Signal Penetration into Buildings	166	(1)
Ray Tracing and Site Specific Modeling	167	(1)
Problems	168	(9)
Mobile Radio Propagation: Small-Scale Fading and Multipath	177	(78)
Small-Scale Multipath Propagation	177	(4)
Factors Influencing Small-Scale Fading	178	(1)
Doppler Shift	179	(2)
Impulse Response Model of a Multipath Channel	181	(11)
Relationship Between Bandwidth and Received Power	185	(7)
Small-Scale Multipath Measurements	192	(5)
Direct RF Pulse System	192	(1)
Spread Spectrum Sliding Correlator Channel Sounding	193	(3)
Frequency Domain Channel Sounding	196	(1)
Parameters of Mobile Multipath Channels	197	(8)
Time Dispersion Parameters	199	(3)
Coherence Bandwidth	202	(1)
Doppler Spread and Coherence Time	203	(2)
Types of Small-Scale Fading	205	(5)
Fading Effects due to Multipath Time Delay Spread	205	(1)
Flat Fading	205	(2)
Frequency Selective Fading	207	(1)
Fading Effects Due to Doppler Spread	208	(1)
Fast Fading	208	(1)
Slow Fading	209	(1)
Rayleigh and Ricean Distributions	210	(4)
Rayleigh Fading Distribution	210	(2)
Ricean Fading Distribution	212	(2)
Statistical Models for Multipath Fading Channels	214	(15)
Clarke's Model for Flat Fading	214	(3)
Spectral Shape Due to Doppler Spread in Clarke's Model	217	(3)
Simulation of Clarke and Gans Fading Model	220	(3)
Level Crossing and Fading Statistics	223	(3)
Two-ray Rayleigh Fading Model	226	(1)
Saleh and Valenzuela Indoor Statistical Model	227	(1)
SIRCIM and SMRCIM Indoor and Outdoor Statistical Models	227	(2)
Theory of Multipath Shape Factors for Small-Scale Fading Wireless Channels	229	(18)
Introduction to Shape Factors	230	(2)
Multipath Shape Factors	232	(1)
Angular Spread, Λ	232	(1)
Angular Constriction, γ	233	(1)
Azimuthal Direction of Maximum Fading, &thetas;max	233	(1)
Fading Rate Variance Relationships	233	(1)
Complex Received Voltage, V(r)	233	(1)
Received Power, P(r)	234	(1)
Received Envelope, R(r)	234	(1)
Comparison to Omnidirectional Propagation	234	(2)
Examples of Fading Behavior	236	(1)
Sector Channel Model	236	(3)
Double Sector Channel Model	239	(1)
Ricean Channel Model	240	(1)
Second-Order Statistics Using Shape Factors	240	(2)
Level-Crossing Rates and Average Fade Duration	242	(1)
Spatial Autocovariance	242	(1)
Coherence Distance	243	(1)
Applying Shape Factors to Wideband Channels	243	(1)
Revisiting Classical Channel Models with Shape Factors	244	(3)
Summary	247	(1)
Problems	248	(7)
Modulation Techniques for Mobile Radio	255	(100)
Frequency Modulation vs. Amplitude Modulation	256	(1)
Amplitude Modulation	257	(7)
Single Sideband AM	260	(1)
Pilot Tone SSB	261	(1)
Demodulation of AM signals	262	(2)
Angle Modulation	264	(13)
Spectra and Bandwidth of FM Signals	266	(1)
FM Modulation Methods	267	(1)
FM Detection Techniques	268	(8)
Tradeoff Between SNR and Bandwidth in an FM Signal	276	(1)
Digital Modulation-an Overview	277	(5)
Factors That Influence the Choice of Digital Modulation	278	(3)
Bandwidth and Power Spectral Density of Digital Signals	281	(1)
Line Coding	282	(1)
Pulse Shaping Techniques	282	(9)
Nyquist Criterion for ISI Cancellation	282	(5)
Raised Cosine Rolloff Filter	287	(3)
Gaussian Pulse-Shaping Filter	290	(1)
Geometric Representation of Modulation Signals	291	(3)
Linear Modulation Techniques	294	(17)
Binary Phase Shift Keying (BPSK)	295	(3)
Differential Phase Shift Keying (DPSK)	298	(2)
Quadrature Phase Shift Keying (QPSK)	300	(1)
QPSK Transmission and Detection Techniques	301	(2)
Offset QPSK	303	(2)
π/4 QPSK	305	(1)
π/4 QPSK Transmission Techniques	305	(3)
π/4 QPSK Detection Techniques	308	(3)
Constant Envelope Modulation	311	(11)
Binary Frequency Shift Keying	312	(2)
Minimum Shift Keying (MSK)	314	(4)
Gaussian Minimum Shift Keying (GMSK)	318	(4)
Combined Linear and Constant Envelope Modulation Techniques	322	(7)
M-ary Phase Shift Keying (MPSK)	323	(2)
M-ary Quadrature Amplitude Modulation (QAM)	325	(3)
M-ary Frequency Shift Keying (MFSK) and OFDM	328	(1)
Spread Spectrum Modulation Techniques	329	(10)
Pseudo-Noise (PN) Sequences	330	(1)
Direct Sequence Spread Spectrum (DS-SS)	331	(3)
Frequency Hopped Spread Spectrum (FH-SS)	334	(1)
Performance of Direct Sequence Spread Spectrum	335	(3)
Performance of Frequency Hopping Spread Spectrum	338	(1)
Modulation Performance in Fading and Multipath Channels	339	(11)
Performance of Digital Modulation in Slow Flat-Fading Channels	340	(4)
Digital Modulation in Frequency Selective Mobile Channels	344	(2)
Performance of π/4 DQPSK in Fading and Interference	346	(4)
Problems	350	(5)
Equalization, Diversity, and Channel Coding	355	(60)
Introduction	355	(1)
Fundamentals of Equalization	356	(3)
Training A Generic Adaptive Equalizer	359	(4)
Equalizers in a Communications Receiver	363	(1)
Survey of Equalization Techniques	364	(2)
Linear Equalizers	366	(2)
Nonlinear Equalization	368	(4)
Decision Feedback Equalization (DFE)	369	(1)
Maximum Likelihood Sequence Estimation (MLSE) Equalizer	370	(2)
Algorithms for Adaptive Equalization	372	(8)
Zero Forcing Algorithm	374	(1)
Least Mean Square Algorithm	374	(2)
Recursive Least Squares Algorithm	376	(3)
Summary of Algorithms	379	(1)
Fractionally Spaced Equalizers	380	(1)
Diversity Techniques	380	(11)
Derivation of Selection Diversity Improvement	381	(3)
Derivation of Maximal Ratio Combining Improvement	384	(1)
Practical Space Diversity Considerations	385	(1)
Selection Diversity	386	(1)
Feedback or Scanning Diversity	386	(1)
Maximal Ratio Combining	387	(1)
Equal Gain Combining	387	(1)
Polarization Diversity	387	(3)
Frequency Diversity	390	(1)
Time Diversity	390	(1)
RAKE Receiver	391	(2)
Interleaving	393	(1)
Fundamentals of Channel Coding	394	(1)
Block Codes and Finite Fields	395	(12)
Examples of Block Codes	399	(1)
Case Study: Reed-Solomon Codes for CDPD	400	(1)
Reed-Solomon Encoding	401	(3)
Reed-Solomon Decoding	404	(3)
Convolutional Codes	407	(4)
Decoding of Convolutional Codes	409	(1)
The Viterbi Algorithm	409	(1)
Other Decoding Algorithms for Convolutional Codes	410	(1)
Coding Gain	411	(1)
Trellis Coded Modulation	412	(1)
Turbo Codes	412	(1)
Problems	412	(3)
Speech Coding	415	(32)
Introduction	415	(2)
Characteristics of Speech Signals	417	(1)
Quantization Techniques	418	(5)
Uniform Quantization	418	(1)
Nonuniform Quantization	419	(2)
Adaptive Quantization	421	(1)
Vector Quantization	422	(1)
Adaptive Differential Pulse Code Modulation (ADPCM)	423	(2)
Frequency Domain Coding of Speech	425	(4)
Sub-band Coding	425	(3)
Adaptive Transform Coding	428	(1)
Vocoders	429	(2)
Channel Vocoders	429	(1)
Formant Vocoders	430	(1)
Cepstrum Vocoders	430	(1)
Voice-Excited Vocoder	431	(1)
Linear Predictive Coders	431	(5)
LPC Vocoders	431	(3)
Multipulse Excited LPC	434	(1)
Code-Excited LPC	434	(2)
Residual Excited LPC	436	(1)
Choosing Speech Codecs for Mobile Communications	436	(4)
The GSM Codec	440	(2)
The USDC Codec	442	(1)
Performance Evaluation of Speech Coders	442	(3)
Problems	445	(2)
Multiple Access Techniques for Wireless Communications	447	(44)
Introduction	447	(2)
Introduction to Multiple Access	448	(1)
Frequency Division Multiple Access (FDMA)	449	(4)
Time Division Multiple Access (TDMA)	453	(3)
Spread Spectrum Multiple Access	456	(5)
Frequency Hopped Multiple Access (FHMA)	457	(1)
Code Division Multiple Access (CDMA)	458	(1)
Hybrid Spread Spectrum Techniques	459	(2)
Space Division Multiple Access (SDMA)	461	(1)
Packet Radio	462	(7)
Packet Radio Protocols	463	(1)
Pure ALOHA	464	(1)
Slotted ALOHA	465	(1)
Carrier Sense Multiple Access (CSMA) Protocols	466	(1)
Reservation Protocols	467	(1)
Reservation ALOHA	467	(1)
Packet Reservation Multiple Access (PRMA)	468	(1)
Capture Effect in Packet Radio	468	(1)
Capacity of Cellular Systems	469	(19)
Capacity of Cellular CDMA	474	(3)
Capacity of CDMA with Multiple Cells	477	(7)
Capacity of Space Division Multiple Access	484	(4)
Problems	488	(3)
Wireless Networking	491	(42)
Introduction to Wireless Networks	491	(2)
Differences Between Wireless and Fixed Telephone Networks	493	(4)
The Public Switched Telephone Network (PSTN)	493	(2)
Limitations in Wireless Networking	495	(1)
Merging Wireless Networks and the PSTN	496	(1)
Development of Wireless Networks	497	(4)
First Generation Wireless Networks	497	(2)
Second Generation Wireless Networks	499	(1)
Third Generation Wireless Networks	500	(1)
Fixed Network Transmission Hierarchy	501	(1)
Traffic Routing in Wireless Networks	502	(4)
Circuit Switching	503	(1)
Packet Switching	504	(1)
The X.25 Protocol	505	(1)
Wireless Data Services	506	(4)
Cellular Digital Packet Data (CDPD)	506	(2)
Advanced Radio Data Information Systems (ARDIS)	508	(1)
RAM Mobile Data (RMD)	508	(2)
Common Channel Signaling (CCS)	510	(2)
The Distributed Central Switching Office for CCS	510	(2)
Integrated Services Digital Network (ISDN)	512	(2)
Broadband ISDN and ATM	513	(1)
Signaling System No. 7 (SS7)	514	(6)
Network Services Part (NSP) of SS7	515	(1)
Message Transfer Part (MTP) of SS7	516	(1)
Signaling Connection Control Part (SCCP) of SS7	517	(1)
The SS7 User Part	517	(1)
Integrated Services Digital Network User Part (ISUP)	517	(1)
Transaction Capabilities Application Part (TCAP)	518	(1)
Operation Maintenance and Administration Part (OMAP)	518	(1)
Signaling Traffic in SS7	518	(1)
SS7 Services	519	(1)
Performance of SS7	519	(1)
An Example of SS7 - Global Cellular Network Interoperability	520	(2)
Personal Communication Services/Networks (PCS/PCNs)	522	(5)
Packet vs. Circuit Switching for PCN	523	(1)
Cellular Packet-Switched Architecture	523	(4)
Network Functionality in Cellular Packet-Switched Architecture	527	(1)
Protocols for Network Access	527	(2)
Packet Reservation Multiple Access (PRMA)	528	(1)
Network Databases	529	(1)
Distributed Database for Mobility Management	529	(1)
Universal Mobile Telecommunication System (UMTS)	530	(1)
Summary	531	(2)
Wireless Systems and Standards	533	(160)
AMPS and ETACS	533	(8)
AMPS and ETACS System Overview	534	(1)
Call Handling in AMPS and ETACS	535	(2)
AMPS and ETACS Air Interface	537	(3)
N-AMPS	540	(1)
United States Digital Cellular (IS-54 and IS-136)	541	(8)
USDC Radio Interface	542	(6)
United States Digital Cellular Derivatives (IS-94 and IS-136)	548	(1)
Global System for Mobile (GSM)	549	(18)
GSM Services and Features	550	(1)
GSM System Architecture	551	(2)
GSM Radio Subsystem	553	(2)
GSM Channel Types	555	(1)
GSM Traffic Channels (TCHs)	555	(2)
GSM Control Channels (CCH)	557	(3)
Example of a GSM Call	560	(1)
Frame Structure for GSM	561	(2)
Signal Processing in GSM	563	(4)
CDMA Digital Cellular Standard (IS-95)	567	(13)
Frequency and Channel Specifications	567	(2)
Forward CDMA Channel	569	(1)
Convolutional Encoder and Repetition Circuit	569	(2)
Block Interleaver	571	(1)
Long PN Sequence	571	(1)
Data Scrambler	572	(1)
Power Control Subchannel	572	(1)
Orthogonal Covering	573	(1)
Quadrature Modulation	574	(1)
Reverse CDMA Channel	575	(1)
Convolutional Encoder and Symbol Repetition	576	(1)
Block Interleaver	576	(1)
Orthogonal Modulation	576	(1)
Variable Data Rate Transmission	576	(2)
Direct Sequence Spreading	578	(2)
Quadrature Modulation	580	(1)
IS-95 with 14.4 kbps Speech Coder [ANS95]	580	(1)
CT2 Standard for Cordless Telephones	580	(2)
CT2 Services and Features	580	(1)
The CT2 Standard	581	(1)
Digital European Cordless Telephone (DECT)	582	(5)
Features and Characteristics	582	(1)
DECT Architecture	582	(2)
DECT Functional Concept	584	(1)
DECT Radio Link	584	(3)
PACS - Personal Access Communication Systems	587	(3)
PACS System Architecture	587	(1)
PACS Radio Interface	587	(3)
Pacific Digital Cellular (PDC)	590	(1)
Personal Handyphone System (PHS)	590	(1)
US PCS and ISM Bands	591	(2)
US Wireless Cable Television	593	(1)
Summary of Standards Throughout the World	594	(3)
Problems	597	(4)
Appendices
A Trunking Theory	601	(10)
A.1 Erlang B	602	(1)
A.1.1 Derivation of Erlang B	602	(5)
A.2 Erlang C	607	(1)
A.2.1 Derivation of Erlang C	607	(4)
B Noise Figure Calculations for Link Budgets	611	(4)
C Rate Variance Relationships for Shape Factor Theory	615	(4)
C.1 Rate Variance for Complex Voltage	615	(2)
C.2 Rate Variance for Power	617	(1)
C.3 Rate Variance for Envelope	617	(2)
D Approximate Spatial Autocovariance Function for Shape Factor Theory	619	(2)
E Gaussian Approximations for Spread Spectrum CDMA	621	(24)
E.1 The Gaussian Approximation	629	(6)
E.2 The Improved Gaussian Approximation (IGA)	635	(2)
E.3 A Simplified Expression for the Improved Gaussian Approximation (SEIGA)	637	(8)
F Q, erf & erfc Functions	645	(6)
F.1 The Q-Function	645	(3)
F.2 The erf and erfc Functions	648	(3)
G Mathematical Tables, Functions, and Transforms	651	(10)
H Abbreviations and Acronyms	661	(14)
I References	675	(18)
Index	693

Excerpts

Preface The second edition of this text has been written to initiate the newcomer to wireless personal communications, one of the fastest growing fields in the engineering world. Technical concepts which are at the core of design, implementation, research, and invention of wireless communication systems are presented in an order that is conducive to understanding general concepts, as well as those specific to current and evolving wireless communication systems and standards. This text is based upon my experiences as an educator, researcher, technical trainer, and consultant, and continues to be modeled from an academic course first developed for electrical engineering students in 1990, when there were fewer than five million cellular subscribers worldwide. As we begin the 21st century, more than 600 million people, about 10% of the world#xD5;s population, pay a monthly subscription for wireless telephone service, and this figure will approach 50% by the end of the first decade of the 21st century. This text continues to evolve, and has been modified and updated since its first edition, making it a useful book for practicing engineers, as well as for researchers, graduate students, and undergraduate students. The text has been prepared to provide fundamental treatment about many practical and theoretical concepts that form the basis of wireless communications, and has been designed for easy but thorough treatment of vital material that all wireless practitioners must be comfortable with. I have tried to emphasize the technical concepts with worked example problems, and numerous, carefully crafted homework problems at the end of each chapter that are based on real-world industry issues. The second edition contains dozens of new homework problems and examples, as well as up-to-the minute technical details of the many emerging wireless standards throughout the world, making this book particularly useful for industry short-courses or state-of-the-art academic classroom use. References to journal articles are used liberally throughout this text to enable the interested reader to delve into additional reading that is always required to master any field. To support newcomers to the wireless field, and at the request of the Institute of Electrical and Electronics Engineers (IEEE), I have also prepared a low-cost two volume compendium of many of the original journal articles that first taught the fundamentals that are now used throughout the wireless industry#xD1;this compendium series is a useful, but not required, supplement to this text. Whether you intend to use this book for individual study, or for classroom use, or for use as a handbook, this text has been written as a complete, self-contained teaching and reference book. The numerous examples and problems found throughout the text have been provided to help the reader solidify the material. This book has been designed for the student or practicing engineer who is already familiar with technical concepts such as probability, communication theory, and basic electromagnetics. However, like the wireless communications industry itself, this book combines material from many different technical disciplines, so it is unlikely that any one person will have had introductory courses for all of the topics covered. To accommodate a wide range of backgrounds, important concepts throughout the text are developed from first principles, so that readers learn the foundations of wireless communications. This approach makes it possible to use this book as a handbook or as a useful teaching tool in a classroom setting. The material and chapter sequence in this text have been adapted from an entry-level graduate course which I first taught in 1991 at the Virginia Polytechnic Institute and State University. Chapter 1 demonstrates the historic evolution of the wireless communications industry, and the evolution of wireless systems from first generation analog to second generation (2G) digital systems. Chapter 1 also documents the rapid early growth of cellular radio throughout the world and provides a state of the industry in the mid 1990s. Chapter 2 provides an overview of the major modern wireless communication systems of the 21 st century, such as third generation (3G), Wireless Local Area Networks (WLANs), Local Multipoint Distribution Services (LMDS), and Bluetooth. Chapter 2 causes the reader to see how wireless networks are beginning to penetrate our daily lives for data and multimedia applications, as well as voice service. Chapter 3 covers fundamental cellular radio concepts such as frequency reuse and handoff, which are at the core of providing wireless communication service to subscribers on the move using limited radio spectrum. Chapter 3 also demonstrates the principal of trunking efficiency, and how trunking and interference issues between mobiles and base stations combine to affect the overall capacity of cellular systems. Chapter 4 presents radio propagation path loss, link-budgets, and log-normal shadowing, and describes different ways to model and predict the large-scale effects of radio propagation in many operating environments. Chapter 5 covers small-scale propagation effects such as fading, time delay spread, and Doppler spread, and describes how to measure and model the impact that signal bandwidth and motion have on the instantaneous received signal through the multipath channel. Radio wave propagation has historically been the most difficult problem to analyze and design for, since unlike a wired communication system which has a constant, stationary transmission channel (i.e., a wired path), radio channels are random and undergo shadowing and multipath fading, particularly when one of the terminals is in motion. New material in Chapter 5 also teaches a fundamental and new way of modeling spatial-temporal channels, which is vital for the development of smart antennasand position location systems. Chapter 6 provides extensive coverage of the most common analog and digital modulation techniques used in wireless communications and demonstrates tradeoffs that must be made in selecting a modulation method. Issues such as receiver complexity, modulation and demodulation implementation, bit error rate analysis for fading channels, and spectral occupancy are presented. Channel coding, adaptive equalization, and antenna diversity concepts are presented in Chapter 7. In portable radio systems where people communicate while walking or driving, these methods may be used individually or in tandem to improve the quality (that is, reduce the bit error rate) of digital mobile radio communications in the presence of fading and noise. Chapter 8 provides an introduction to speech coding. In the past decade, there has been remarkable progress in decreasing the needed data rate of high quality digitized speech, which enables wireless system designers to match end-user services to network architectures. Principles which have driven the development of adaptive pulse code modulation and linear predictive coding techniques are presented, and how these techniques are used to evaluate speech quality in existing and proposed cellular, cordless, and personal communication systems are discussed. Chapter 9 introduces time, frequency, and code division multiple access, as well as more recent multiple access techniques such as packet reservation and space division multiple access. Chapter 9 also describes how each access method can accommodate a large number of mobile users and demonstrates how multiple access impacts capacity and the network infrastructure of a cellular system. Chapter 10 describes networking considerations for wide area wireless communication systems, and presents practical networking approaches that are in use or have been proposed for future wireless systems. Chapter 11 unites all of the material from the first nine chapters by describing and comparing