Principles of Mobile Communication. Second Edition

Transcription

1 Principles of Mobile Communication Second Edition

2 Principles of Mobile Communication Second Edition Gordon L. Stüber Georgia Institute of Technology Atlanta, Georgia USA KLUWER ACADEMIC PUBLISHERS NEW YORK, BOSTON, DORDRECHT, LONDON, MOSCOW

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4 Contents Preface INTRODUCTION 1.1 Wireless Systems and Standards First Generation Cellular Systems Second Generation Cellular Systems GSM/DCS1800/PCS IS-54/136 and IS PDC Cordless Telephone Systems Third Generation Cellular Systems Wireless LANs and and PANs 1.2 Frequency Reuse and the Cellular Concept 1.3 Mobile Radio Propagation Environment 1.4 Co-channel Interference and Noise 1.5 Receiver Sensitivity and Link Budget 1.6 Coverage 1.7 Spectral Efficiency and Capacity PROPAGATION MODELING 2.1 Frequency-Non-Selective (Flat) Multipath-Fading Received Signal Correlation and Spectrum Received Envelope and Phase Distribution Rayleigh Fading Ricean Fading Nakagami Fading Envelope Phase Envelope Correlation and Spectra Squared-Envelope Correlation and Spectra Level Crossing Rates and Fade Durations Envelope Level Crossing Rate Zero Crossing Rate Average Envelope Fade Duration Spatial Correlations xiii

5 vi PRINCIPLES OFMOBILE COMMUNICATION SECOND EDITION Received Signal at the Base Station Frequency-Selective Multipath-Fading Statistical Channel Correlation Functions Classification of Channels Channel Output Autocorrelation Laboratory Simulation of Multipath-Fading Channels Filtered Gaussian Noise Sum of Sinusoids Method Multiple Faded Envelopes Simulation of Wide-band Multipath-Fading Channels Shadowing Laboratory Simulation of Shadowing Composite Shadowing-Fading Distributions Composite Gamma-log-normal Distribution Path Loss Models Path Loss in Macrocells Okumura-Hata and CCIR Models Lee s Area-to-Area Model Path Loss in Outdoor Microcells COST231-Hata Model COST231-Walfish-Ikegami Model Street Microcells Path Loss in Indoor Microcells CO-CHANNEL INTERFERENCE 3.1 Multiple Log-normal Interferers Fenton-Wilkinson Method Schwartz-and Yeh-Method Parley s Method Numerical Comparisons 3.2 Probability of Outage 3.3 Multiple Ricean/Rayleigh Interferers 3.4 Multiple Log-normal Nakagami Interferers Statistically Identical Interferers 3.5 Multiple Log-normal Ricean/Rayleigh Interferers Single Interferer Multiple Interferers 4. MODULATED SIGNALS AND THEIR POWER SPECTRA Representation of Band-pass Modulated Signals Vector Space Representations Gram-Schmidt Procedure Signal Energy and Correlations Nyquist Pulse Shaping Quadrature Amplitude Modulation (QAM) Phase Shift Keying (PSK) Offset QPSK (OQSPK)

6 Contents vii DIGITAL SIGNALING ON FLAT FADING CHANNELS Orthogonal Modulation and Variants Orthogonal Frequency Division Multiplexing (OFDM) Multiresolution Modulation FFT-Based OFDM System Continuous Phase Modulation (CPM) Full Response CPM Minimum Shift Keying (MSK) Partial Response CPM Gaussian Minimum Shift Keying (GMSK) Linearized OMSK (LGMSK) Tamed Frequency Modulation (TFM) Power Spectral Densities of Digitally Modulated Signals Psd of a Complex Envelope Psd of QAM Psd of PSK Psd of OQPSK Psd of Psd of OFDM Psd of Full Response CPM Psd of CPFSK Psd of MSK Psd of GMSK and TFM Vector Space Representation of Received Signals Detection of Known Signals in Additive White Gaussian Noise Probability of Error Pairwise Error Probability Upper Bounds on Error Probability Lower Bound on Error Probability Bit Versus Symbol Error Probabilities Error Probability of PSK Error Probability of M-QAM Error Probability of Orthogonal Signals Error Probability of OFDM Error Probability of MSK Differential Detection Differential Detection of Non-coherent Detection Detection of CPM Signals Coherent CPM Demodulator Non-coherent CPM Demodulator ANTENNA DIVERSITY 6.1 Diversity Combining

7 viii PRINCIPLES OFMOB1LE COMMUNICATION SECOND EDITION Selective Combining Maximal Ratio Combining Equal Gain Combining Switched Combining Differential Detection with Equal Gain Combining Transmitter Diversity Space-Time Transmit Diversity 7. EQUALIZATION AND INTERFERENCE CANCELLATION 7.1 Overview Symbol-by-symbol Equalizers Sequence Estimation Co-Channel Interference Cancellation 7.2 Modeling of ISI Channels Vector Representation of Received Signals 7.3 Optimum Receiver for ISI Channels with AWGN Discrete-Time White Noise Channel Model Time Varying Channels with Diversity T/2-Spaced Receiver 7.4 Symbol-by-Symbol Equalizers Linear Equalizer Zero-Forcing (ZF) Minimum Mean-Square-Error (MMSE) Decision Feedback Equalizer (DFE) Comparison of Symbol-by-symbol Equalizers 7.5 Sequence Estimation MLSE and the Viterbi Algorithm Adaptive MLSE Receiver T/2-spaced MLSE Receiver Delayed Decision-Feedback Sequence Estimation Reduced-State Sequence Estimation 7.6 Error Probability for MLSE on ISI Channels Static ISI Channels Fading ISI Channels Computing the Union Bound Error-State Diagram The Stack Algorithm Examples 7.7 Error Probability for T/2-spaced MLSE Receiver T-spaced MLSE Receiver T/2-spaced MLSE Receiver Practical T/2-spaced MLSE Receiver Timing Phase Sensitivity 7.8 MIMO MLSE Receivers System and Channel Model Joint Maximum Likelihood Sequence Estimation

8 Contents ERROR CONTROL CODING 8.1 Block Codes Binary Block Codes Minimum Distance Syndromes Error Detection Weight Distribution Probability of Undetected Error Error Correction Standard Array Decoding Syndrome Decoding 8.2 Convolutional Codes Encoder Description State and Trellis Diagrams, and Weight Distribution Recursive Systematic Convolutional (RSC) Codes 8.3 Trellis Coded Modulation Encoder Description Mapping by Set Partitioning 8.4 Coded Performance on AWGN Channels Union Bound for Convolutional Codes 8.5 Coded Performance on Interleaved Flat Fading Channels Design Rules for TCM on Flat Fading Channels Multidimensional TCM Multiple TCM (MTCM) D Trellis Codes 8.6 Coded Performance on ISI Channels TCM on Static ISI Channels TCM on Noninterleaved Fading ISI Channels Examples Static ISI Channels Multipath Fading ISI Channels Evaluation of Union Bounds for TCM Turbo Codes Discrete-time MIMO Channel Model The Viterbi Algorithm Pairwise Error Probability T/2-Spaced MIMO MLSE Receiver Error Probability Timing Phase Sensitivity Practical Receiver Interference Rejection Combining MLSE Examples PCCC Encoder PCCC Decoder SCCC Encoder and Decoder Weight Distribution Weight Distribution of PCCCs ix

9 x PRINCIPLES OFMOBILE COMMUNICATION SECOND EDITION Weight Distribution of SCCCs SPREAD SPECTRUM TECHNIQUES 9.1 Basic Principles of Spread Spectrum Direct Sequence (DS) Spread Spectrum Frequency Hop (FH) Spread Spectrum 9.2 Spreading Sequences Spreading Waveforms m-sequences Gold Sequences Kasami Sequences Barker Sequences Walsh-Hadamard Sequences Orthogonal and Bi-orthogonal Modulation Variable Length Orthogonal Codes Complementary Code Keying (CCK) 9.3 Power Spectral Density of DS Spread Spectrum Signals 9.4 Performance of DS/OPSK in Tone Interference 9.5 DS Spread Spectrum on Frequency-Selective Fading Channels RAKE Receiver 9.6 Error Probability for DS CDMA on AWGN Channels Standard Gaussian Approximation Improved Gaussian Approximation Simplified Gaussian Approximation 10. TDMA CELLULAR ARCHITECTURES 10.1 Cell Sectoring Cell Sectoring with Wide-beam Directional Antennas Sectoring with Switched-beam Antennas Trunkpool Techniques Cellular Performance with Switched-beam Antennas Reverse Channel Forward Channel Performance Criteria and Results 10.2 Conventional Cell Splitting Reuse Partitioning Cell Splitting with Reuse Partitioning 10.3 Cluster Planned Hierarchical Architecture System Architecture Underlaid Microcell Planning Algorithm Performance Analysis of Cluster Planned Architecture Macrocell Performance Microcell Performance Adjacent Channel Interference Analysis 10.4 Macrodiversity Architectures Probability of Co-channel Interference Outage Shadow Correlation Numercial Examples

10 11. CDMA CELLULAR ARCHITECTURES 11.1 Capacity of Cellular CDMA Reverse Link Capacity Forward Link Capacity Imperfect Power Control 11.2 Error Probability with RAKE Reception Maximal Ratio Combining 13. CHANNEL ASSIGNMENT TECHNIQUES 13.1 Centralized DCA Maximum Packing (MP) MAXMIN Scheme 13.2 Decentralized DCA First Available (FA) and Nearest Neighbor (NN) Dynamic Resource Acquisition (DRA) 13.3 Fully Decentralized DCA Channel Segregation (CS) Channel Segregation with Variable Threshold Minimum Interference (MI) Schemes Contents 12. LINK QUALITY MEASUREMENT AND HANDOFF INITIATION 12.1 Signal Strength Based Hard Handoff Algorithms 12.2 Pilot-to-interference Ratio Based Soft Handoff Algorithms 12.3 Signal Strength Averaging Choosing the Proper Window Length Choosing the Proper Number of Samples to Average 12.4 Velocity Estimation in Cellular Systems Level Crossing Rate Estimators Covariance Approximation Methods Velocity Estimator Sensitivity Effect of the Scattering Distribution Effects of Additive Gaussian Noise 12.5 Velocity Adaptive Handoff Algorithms Effect of Corner Effects and Sensitivity to a and Velocity Adaptive Handoff Performance 12.6 Hard Handoff Analysis Simulation Results 12.7 Soft Handoff Analysis Simulation Results 12.8 CIR-based Link Quality Measurements Discrete-Time Model for Signal Quality Estimation Estimation of (I+N) Estimation of C/(I+N) Training Sequence Based C/(I+N) Estimation 12.9 Summary xi

11 xii PRINCIPLES OFMOBILE COMMUNICATION SECOND EDITION Handoff Priority 13.10Example DCA Schemes for TDMA Systems The Simple DCA (SDCA) Strategy A Queueing DCA Strategy An Aggressive DCA Strategy Simulation Model, Results, and Discussion Concluding Remarks Appendix A Probability and Random Processes A.1 Conditional Probability and Bayes Theorem A.2 Means, Moments, and Moment Generating Functions A.3 Some Useful Probability Distributions A.4 A.5 References Index Aggressive and Timid DCA Strategies Hybrid FCA/DCA Schemes Borrowing Schemes Borrowing with Channel Ordering (BCO) Borrowing with Directional Locking Borrowing without Locking Compact Pattern Based DCA Directed Retry and Directed Handoff Moving Direction Strategies Reduced Transceiver Coverage Reuse Partitioning A.3.1 Discrete Distributions A.3.2 Continuous Distributions Upper Bounds on the cdfc Random Processes A.5.1 Moments and Correlation Functions A.5.2 Crosscorrelation and Crosscovariance A.5.3 Complex-Valued Random Processes A.5.4 Power Spectral Density A.5.5 Random Processes Filtered by Linear Systems A.5.6 Discrete-time Random Processes A.5.7 Cyclostationary Random Processes

12 Preface This book follows from my first edition and is intended to provide a thorough, up to date, treatment of wireless physical communications. The book is derived from a compilation of course material that I have taught in a graduatelevel course on physical wireless communications at Georgia Tech over the past decade. This textbook differs from others on the subject by stressing mathematical modeling and analysis. My approach is to include detailed derivations from first principles. The text is intended to provide enough background material for the novice student enrolled in a graduate level course, while having enough advanced material to prime the more serious graduate students that would like to pursue research in the area. The book is intended to stress the fundamentals of mobile communications engineering that are important to any mobile communication system. I have therefore kept the description of existing and proposed wireless standards and systems to a minimum. The emphasis on fundamental issues should benefit not only to students taking formal instruction, but also practicing engineers who are likely to already have a detailed familiarity with the standards and are seeking to deepen their knowledge of the fundamentals and principles of this important field. Chapter 1 begins with an overview that is intended to introduce a broad array of issues relating to wireless communications. Included is a description of various wireless systems and services, basic concepts of cellular frequency reuse, and the link budget for cellular radio systems. Chapter 2 treats propagation modeling and was inspired by the excellent reference by Jakes. It begins with a summary of propagation models for narrow-band and wide-band multipath channels, and provides a discussion of channel simulation techniques that are useful for radio link analysis. It concludes with a discussion of shadowing and path loss models. Chapter 3 is a related chapter that provides a detailed treatment of co-channel interference, the primary impairment in high capacity cellular systems.

13 xiv PRINCIPLES OF MOBILE COMMUNICATION SECOND EDITION Chapter 4 covers the various types of modulation schemes that are used in mobile communication systems along with their spectral characteristics. Chapter 5 discusses the performance of digital signal on narrow-band flat fading channels with a variety of receiver structures, while Chapter 6 includes a treatment of antenna diversity techniques. Chapter 7 provides an extensive treatment of digital signaling on the fading ISI channels that are typical of mid-band land mobile radio systems. The chapter begins with the characterization of ISI channels and goes on to discuss techniques for combating ISI based on symbol-by-symbol equalization and sequence estimation. The chapter concludes with a discussion of co-channel demodulation and co-channel interference cancellation. Chapter 8 covers bandwidth efficient coding techniques. The chapter begins with a discussion of basic block and convolutional coding. It then goes on to a detailed discussion on the design and performance analysis of convolutional and trellis codes for additive white Gaussian noise channels, and interleaved flat fading channels. The chapter concludes with an introduction to Turbo coding. Chapter 9 is devoted to spread spectrum techniques. The chapter begins with an introduction to direct sequence and frequency hop spread spectrum. This is followed by a detailed treatment of spreading sequences. Also included is a discussion of the effects of tone interference on direct sequence spread spectrum, and the RAKE receiver performance on wide-band channels. The chapter wraps up with a discussion of the error probability of direct sequence code division multiple access. Chapter 10 considers TDMA cellular architectures. The chapter begins with a discussion of conventional TDMA systems and how they are evolved to meet traffic growth. This is followed by hierarchical overlay/underlay architectures. Finally, the chapter wraps up with macrodiversity TDMA architectures. Chapter 11 is the CDMA counterpart to Chapter 10 and considers issues that are relevant to cellular CDMA, such as capacity estimation and power control. Chapter 10 covers the important problem of link quality evaluation and handoff initiation, and handoff performance, in cellular systems. Chapter 11 provides an overview of the various channel assignment techniques that have been proposed for FDMA and TDMA cellular systems. The book contains far too much detail to be taught in a one-semester course. However, I believe that it can serve as a suitable text in most situations through the appropriate selection of material. My own preference for a one-semester course is to include the following in order: Chapter 1, Chapter 2, Sections 3.1 and 3.2, Chapter 4, Chapter 5, and Chapter 6. Then choose from Chapters 8 through 13 depending on my interest at the time. I would like to acknowledge all those who have contributed to the preparation of this book. The reviewers Vijay Bhargava at the University of Victoria and Sanjiv Nanda at Lucent Technologies were very valuable in the early

14 Preface xv stages of the first edition of this book. The subsequent review by Upamanyu Madhow at the University of Illinois and in particular the detailed review by Keith Chugg at the University of Southern California were highly useful for improving this book. I am grateful to my doctoral students, past and present, who have contributed significantly to this book. The contributions of Wern-Ho Sheen, Khalid Hamied, Mark Austin, Jeff (Lihbor) Yiin, Ming-Ju Ho, Li-Chun (Robert) Wang, Krishna Narayanan, Dukhyun Kim, Jinsoup Joung, and John (Yongchae) Kim are particularly noteworthy. Finally, I would like to thank BellSouth, GTE Labs, Motorola, Panasonic, Hitachi, Nortel, Korea Telecom, WiLAN, and the National Science Foundation, for sustaining my research efforts in wireless communications over the past 10 years. This research experience has in many cases lead to material that I brought to the classroom and have included in this book. GORDON L. STÜBER

15 To my parents Beatrice and Lothar Stüber