PART 1 INTRODUCTION TO SPREAD-SPECTRUM COMMUNICATIONS 3
Chapter 1 A Spread-Spectrum Overview 3
1.1 A Basis for a Jamming Game 3
1.2 Energy Allocation Strategies 6
1.3 Spread-Spectrum System Configurations and Components 9
CONTENTS 15
Preface15 15
Preface to First Edition 16
1.4 Energy Gain Calculations for Typical Systems 17
1.5 The Advantages of Spectrum Spreading 20
1.5.1 Low Probability of Intercept (LPI) 20
1.5.2 Independent Interference Rejection and Multiple-Access Operation 25
1.5.3 High-Resolution Time-of-Arrival (TOA)Measurements 29
2.3.1 Characterization of the Transmitted Signal 31
1.6 Design Issues 37
1.7 References 38
1.7.1 Books on Communication Theory 38
1.7.4 Spread-Spectrum Tutorials and General Interest Papers 39
1.7.2 Books on Resolution and Ambiguity Functions 39
1.7.3 Recent Books and Proceedings on Spread-Spectrum Communications 39
Chapter 2 The Historical Origins of Spread-Spectrum Communications 41
2.1.1 Radar Innovations 42
2.1 Emerging Concepts 42
2.1.2 Developments in Communication Theory 45
2.1.3 Correlator Mechanization 47
2.1.4 Protected Communications 48
2.1.5 Remote Control and Missile Guidance 58
2.2 Early Spread-Spectrum Systems 65
2.2.1 WHYN 65
2.2.2 A Note on CYTAC 71
2.2.3 Hush-Up 71
2.2.4 BLADES 73
2.2.5 Noise Wheels 78
2.2.6 The Hartwell Connection 84
2.2.7 NOMAC 87
2.2.8 F9C-A/Rake 90
2.2.9 A Note on PPM 100
2.2.10 CODORAC 100
2.2.11 M-Sequence Genesis 106
2.2.12 AN/ARC-50 Development at Magnavox 108
2.3.1 Spread-Spectrum Radar 111
2.3 Branches on the SS Tree 111
2.3.2 Other Early Spread-Spectrum Communication Systems 112
2.3.3 Spread-Spectrum Developments Outside the United States 121
2.4 A Viewpoint 123
2.5 References 125
3.1 Design Approach for Anti-Jam Systems 137
Chapter 3 Basic Concepts and System Models 137
3.2 Models and Fundamental Parameters 139
3.3 Jammer Waveforms 141
3.3.1 Broadband and Partial-Band Noise Jammers 141
3.3.2 CW and Multitone Jammers 143
3.3.3 Pulse Jammer 143
3.3.4 Arbitrary Jammer Power Distributions 143
3.3.5 Repeat-Back Jammers 144
3.4 Uncoded Direct-Sequence Spread Binary Phase-Shift-Keying 144
3.4.1 Constant Power Broadband Noise Jammer 147
3.4.2 Pulse Jammer 150
3.5 Coded Direct-Sequence Spread Binary Phase-Shift-Keying 153
3.5.1 Interleaver and Deinterleaver 158
3.5.2 Unknown Channel State 159
3.5.2.1 Soft Decision Decoder 160
3.5.2.2 Hard Decision Decoder 162
3.5.3 Known Channel State 165
3.5.3.1 Soft Decision Decoder 166
3.5.3.2 Hard Decision Decoder 168
3.6 Uncoded Frequency-Hopped Binary Frequency-Shift-Keying 169
3.6.1 Constant Power Broadband Noise Jammer 172
3.6.2 Partial-Band Noise Jammer 174
3.6.3 Multitone Jammer 176
3.7 Coded Frequency-Hopped Binary Frequency-Shift-Keying 178
3.8 Interleaver/Hop Rate Tradeoff 180
3.9 Receiver Noise Floor 180
3.10 Discussion 183
3.11 References 183
Appendix 3A: Interleaving and Deinterleaving 184
Chapter 4 General Analysis of Anti-Jam Communication Systems 189
4.1 System Model 190
4.2 Coded Bit Error Rate Bound 194
4.3 Cutoff Rates 196
4.4 Conventional Coherent BPSK 198
4.5 DS/BPSK and Pulse Jamming 204
4.6 Translation of Coded Error Bounds 205
4.7 Conventional Non-Coherent MFSK 208
4.7.1 Uncoded 208
4.7.2 Coded 213
4.8 FH/MFSK and Partial-Band Jamming 217
4.9 Diversity for FH/MFSK 227
4.10.1 Binary Super Channel 235
4.10 Concatenation of Codes 235
4.10.3 Reed-Solomon Outer Codes 238
4.10.2 M-ary Super Channel 238
4.11 Summary of Bit Error Bounds 246
4.11.1 DS/BPSK with Pulse Jamming 246
4.11.2 FH/MFSK with Partial-Band Noise Jamming 247
4.11.3 Coding Functions 249
4.12 References 249
Appendix 4A: Chernoff Bound 250
Appendix 4B: Factor of One-Half in Error Bounds 251
Appendix 4C: Reed-Solomon Code Performance 260
Chapter 5 Pseudonoise Generators 264
5.1 The Storage/Generation Problem 264
5.2 Linear Recursions 271
5.2.1 Fibonacci Generators 271
5.2.2 Formal Power Series and Characteristic Polynomials 273
5.2.3 Galois Generators 275
5.2.4 State Space Viewpoint 278
5.2.5 Determination of Linear Recursions from Sequence Segments 280
5.3.1 Partial Fraction Decompositions 281
5.3 Memory-Efficient Linear Generators 281
5.3.2 Maximization of Period for a Fixed Memory Size 283
5.3.3 Repeated Factors in the Characteristic Polynomial 284
5.3.4 M-Sequences 285
5.4 Statistical Properties of M-Sequences 286
5.4.1 Event Counts 287
5.4.2 The Shift-and-Add Property 288
5.4.3 Hamming Distance Properties of Derived Real-Integer Sequences 289
5.4.4 Correlation Properties of Derived Complex Roots-of-Unity Sequences 291
5.5 Galois Field Connections 297
5.5.1 Extension Field Construction 297
5.5.2 The LFSR as a Galois Field Multiplier 298
5.5.3 Determining the Period of Memory Cell Outputs 299
5.5.4 The Trace Representation of M-Sequences 301
5.5.5 A Correlation Computation 304
5.5.6 Decimations of Sequences 305
5.6 Non-Linear Feed-Forward Logic 307
5.6.1 A Powers-of-α Representation Theorem 307
5.6.2 Key's Bound on Linear Span 311
5.6.3 Difference Set Designs 315
5.6.4 GMW Sequences 317
5.7 Direct-Sequence Multiple-Access Designs 326
5.7.1 A Design Criterion 326
5.7.2 Welch's Inner Product Bound 327
5.7.3 Cross-correlation of Binary M-Sequences 329
5.7.4 Linear Designs 334
5.7.5 A Transform-Domain Design Philosophy 340
5.7.6 Bent Sequences 344
5.8.1 Design Criteria 352
5.8 Frequency-Hopping Multiple-Access Designs 352
5.8.2 A Bound on Hamming Distance 353
5.8.3 An FHMA Design Employing an M-Sequence Generator 354
5.8.4 Reed-Solomon Sequences 355
5.9 A Look at the Literature 360
5.10 References 362
Appendix 5A: Finite Field Arithmetic 367
Appendix 5B: Factorizations of 2n—1 and Selected Primitive Polynomials 398
PART 2 CLASSICAL SPREAD-SPECTRUM COMMUNICATIONS 405
Chapter 1 Coherent Direct Sequence Systems 405
1.1 Direct-Sequence Spread Coherent Binary Phase-Shift Keying 407
1.2 Uncoded Bit Error Probability for Arbitrary Jammer Wave forms 409
1.2.1 Chernoff Bound 410
1.2.2 Gaussian Assumptions 411
1.3 Uncoded Bit Error Probability for Specific Jammer Waveforms 412
1.3.1 CW Jammer 414
1.3.2 Random Jammer 416
1.4.1 Arbitrary Time Distribution 418
1.4 Pulse Jamming 418
1.4.2 Worst Case Jammer 420
1.5 Standard Codes and Cutoff Rates 422
1.5.1 The Additive White Gaussian Noise Channel 422
1.5.2 Jamming Channels 424
1.6.1 Continuous Jammer with No Coding 428
1.6 Slow Frequency Non-Selective Fading Channels 428
1.6.2 Continuous Jammer with Coding—No Fading Estimate 430
1.6.3 Continuous Jammer with Coding—Fading Estimate 436
1.6.4 Pulse Jammer withNo Coding 441
1.7 Slow Fading Multipath Channels 442
1.8 Other Coding Metrics for Pulse Jamming 453
1.9 Discussion 460
1.10 References 462
Chapter 2 Non-Coherent Frequency-Hopped Systems 464
2.1 Broadband Noise Jamming 471
2.2.1 Partial-Band Noise Jamming 475
2.2 Worst Case Jamming 475
2.2.2 Multitone Jamming 480
2.2.2.1 Random JammingTone Phase 483
2.2.2.2 Band Multitone Jamming 484
2.2.2.3 Independent Multitone Jamming 493
2.3 Coding Countermeasures 497
2.3.1 Time Diversity 497
2.3.1.1 Partial-Band Noise Jamming 500
2.3.1.2 Band Multitone Jamming 512
2.3.1.3 Independent Multitone Jamming 535
2.3.1.4 Time Diversity Overview 540
2.3.2 Coding Without Diversity 546
2.3.2.1 Convolutional Codes 547
2.3.2.2 Reed-Solomon Codes 562
2.3.2.3 Concatenated Codes 565
2.3.3 Coding With Diversity 567
2.3.3.1 Optimum Code Rates 593
2.4 Slow Fading Uniform Channels 600
2.4.1 Broadband Jamming—No Diversity 602
2.4.2 Broadband Jamming—Diversity and Coding 604
2.4.3 Partial-Band Jamming 612
2.5 Worst Noise Jammer Distribution—Slow Fading Uniform Channel 615
2.5.1 Uncoded 615
2.5.2 Diversity and Coding 619
2.6 Worst Noise Jammer Distribution—Slow Fading Nonuniform Channel 622
2.6.1 Uncoded 623
2.6.2 Diversity and Coding 626
2.7 Other Coding Metrics 630
2.7.1 Energy Quantizer 633
2.7.2 Hard Decision with One Bit Quality Measure 636
2.7.3 List Metric 641
2.7.4 Metrics for Binary Codes 652
2.8 References 660
Appendix 2A: Justification of Factor of 1/2 for FH/MFSK Signals with Diversity in Partial-Band Noise 662
Appendix 2B: Combinatorial Computation for n = 1 Band Multitone Jamming 664
PART 3 OTHER FREQUENCY-HOPPED SYSTEMS 669
Chapter 1 Coherent Modulation Techniques 669
1.1 Performance of FH/QPSK in the Presence of Partial-Band Multitone Jamming 670
1.2 Performance of FH/QASK in the Presence of Partial-Band Multitone Jamming 680
1.3 Performance of FH/QPSK in the Presence of Partial-Band Noise Jamming 687
1.4 Performance of FH/QASK in the Presence of Partial-Band Noise Jamming 690
1.5 Performance of FH/PN/QPSK in the Presence of Partial-Band Multitone Jamming 693
1.6 Performance of FH/PN/QASK in the Presence of Partial-Band Multitone Jamming 698
1.7 Performance of FH/QPR in the Presence of Partial-Band Multitone Jamming 699
1.8 Performance of FH/QPR in the Presence of Partial-Band Multitone Jamming 710
1.9 Summary and Conclusions 713
1.10 References 713
Chapter 2 Differentially Coherent Modulation Techniqnes 715
2.1 Performance of FH/MDPSK in the Presence of Partial-Band Multitone Jamming 716
2.1.1 Evaluation of Q2πn/m 719
2.2 Performance of FH/MDPSK in the Presence of Partial-Band Noise Jamming 728
2.3 Performance of DQASK in the Presence of Additive White Gaussian Noise 731
2.3.2 Receiver Characterization and Performance 732
2.4 Performance of FH/DQASK in the Presence of Partial-Band Multitone Jamming 739
2.5 Performance of FH/DQASK in the Presence of Partial-Band Noise Jamming 748
2.6 References 749
PART 4 SYNCHRONIZATION OF SPREAD-SPECTRUM SYSTEMS 753
Chapter 1 Pseudonoise Acquisition in Direct Sequence Receivers 753
1.1 Historical Survey 753
1.2 The Single Dwell Serial PN Acquisition System 765
1.2.1 Markov Chain Acquisition Model 767
1.2.2 Single Dwell Acquisition Time Performance in the Absence of Code Doppler 770
1.2.3 Single Dwell Acquisition Time Performance in the Presence of Code Doppler and Doppler Rate 777
1.2.4 Evaluation of Detection Probability PD and False Alarm Probability PFA in Terms of PN Acquisition System Parameters 781
1.2.5 Effective Probability of Detection and Timing Misalignment 785
1.2.6 Modulation Distortion Effects 786
1.2.7 Reduction in Noise Spectral Density Caused by PN Despreading 786
1.2.8 Code Doppler and Its Derivative 787
1.2.9 Probability of Acquisition for the Single Dwell System 789
1.3 The Multiple Dwell Serial PN Acquisition System 794
1.3.1 Markov Chain Acquisition Model 798
1.3.2 Multiple Dwell Acquisition Time Performance 801
1.4.1 The Flow Graph Technique 811
1.4 A Unified Approach to Serial Search Acquisition with Fixed Dwell Times 811
1.5 Rapid Acquisition Using Matched Filter Techniques 817
1.5.1 Markov Chain Acquisition Model and Acquisition Time Performance 824
1.5.2 Evaluation of Detection and False Alarm Probabilities for Correlation and Coincidence Detectors 827
1.5.2.1 Exact Results 829
1.5.2.2 Approximate Results 831
1.5.2.3 Acquisition Time Performance 833
1.6 PN Sync Search Procedures and Sweep Strategies for a Non-Uniformly Distributed Signal Location 834
1.6.1 An Example—Single Dwell Serial Acquisition with an Optimized Expanding Window Search 838
1.6.2 Application of the Circular State Diagram Approach 843
1.7 PN Synchronization Using Sequential Detection 860
1.7.1 A Brief Review of Sequential Hypothesis Testing as Applied to the Non-Coherent Detection of a Sine Wave in Gaussian Noise 864
1.7.2 The Biased Square-Law Sequential Detector 867
1.7.3 Probability of False Alarm and Average Test Duration in the Absence of Signal 868
1.7.4 Simulation Results 877
1.8 Search/Lock Strategies 885
1.8.1 Mean and Variance of the Acquisition Time 887
1.8.1.1 Evaluation of Probability Lock 890
1.8.1.2 Evaluation of Mean Dwell Time 891
1.8.2 Another Search/Lock Strategy 896
1.9 Further Discussion 898
1.10 References 899
Chapter 2 Pseudonoise Tracking in Direct Sequence Receivers 903
2.1.1 Mathematical Loop Model and Equation of Operation 904
2.1 The Delay-Locked Loop 904
2.1.2 Statistical Characterization of the Equivalent Additive Noise 909
2.1.3 Linear Analysis of DLL Tracking Performance 911
2.2 The Tau-Dither Loop 915
2.2.1 Mathematical Loop Model and equation of Operation 916
2.2.2 Statistical Characterization of the Equivalent Additive Noise 920
2.2.3 Linear Analysis of TDL Tracking Performance 922
2.3 Acquisition (Transient) Behavior of the DLL and TDL 928
2.4 Mean Time to Loss-of-Lock for the DLL and TDL 933
2.5 The Double Dither Loop 935
2.6 The Product of Sum and Difference DLL 937
2.7 The Modified Code Tracking Loop 941
2.8 The Complex Sums Loop (A Phase-Sensing DLL) 948
2.9 Quadriphase PN Tracking 949
2.10 Further Discussio 952
2.11 References 956
Chapter 3 Time and Frequency Synchronization of Frequency-Hopped Receivers 958
3.1 FH Acquisition Techniques 959
3.1.1 Serial Search Techniques with Active Correlation 959
3.1.2 Serial Search Techniques with Passive Correlation 983
3.1.3 Other FH Acquisition Techniques 985
3.2 Time Synchronization of Non-Coherent FH/MFSK Systems 989
3.2.1 The Case of Full-Band Noise jamming 992
3.2.1.1 Signal Model and Spectral Computations 992
3.2.1.2 Results of Large Nh 997
3.2.2 The Case of Partial-Band Noise Jamming 999
3.2.2.1 Results of Large pNh 1000
3.2.3 The Effects of Time Synchronization Error on FH/MFSK Error Probability Performance 1001
3.2.3.1 Conditional Error Probability Performance—No Diversity 1002
3.2.3.2 Conditional ErrorProbability Performance—m-Diversity with Non-Coherent Combining 1006
3.2.3.3 Average Error Probability Performance in the Presence of Time Synchronization Error Estimation 1009
3.3 Frequency Synchronization of Non-Coherent FH/MFSK Systems 1011
3.3.1 The Case of Full-Band Noise Jamming 1013
3.3.1.1 Signal Model and Spectral Computations 1013
3.3.2 The Case of Partial-Band Noise Jamming 1017
3.3.3 The Effects of Frequency Synchronization Error on FH/MFSK Error Probability Performance 1017
3.3.3.1 Average Error Probability Performance in the Presence of Frequency Synchronization Error Estimation 1022
3.4 References Appendix 3A: To Prove That a Frequency Estimator Based upon Adjacent Spectral Estimates Taken at Integer Multiples of 1/T Cannot be Unbiased 1026
PART 5 SPECIAL TOPICS 1033
Chapter 1 Low Probability of Intercept Communications 1033
1.1 Signal Modulation Forms 1035
1.2 Interception Detectors 1036
1.2.1 ldeal and Realizable Detectors 1037
1.2.1.1 Detectability Criteria 1037
1.2.1.2 Maximum or Bounding Performance of Fundamental Detector Types 1037
(1) Wideband Energy Detector(Radiometer) 1038
(2) Optimum Multichannel FH Pulse-Matched Energy Detector 1040
(3) Filter Bank Combiner (FBC) Detector 1045
(4) Partial-band Filter Bank Combiner(PB-FBC) 1050
1.2.1.3 Signal Structures and Modulation Considerations 1055
1.2.2 Non-idealistic Detector Performance 1059
1.2.2.1 The Problem of Time Synchronization 1059
(1) Wideband Detector with Overlapping I Ds Each of Duration Equal to That of the Message 1059
(2) Wideband Detector with Single(Non-overlapping) I D of Duration Equal to Half of the Message Duration 1063
(3) Wideband Detector with a Continuous Integration Post-Detection RC Filter 1064
(4) Filter Bank Combiner with Overlapping I Ds Each of Hop Interval Duration 1066
1.2.2.2 The Problem of Frequency Synchronization 1070
(1) Doppler Effects 1070
(2) Performance of the FBC with Frequency Error 1070
(1) Wideband Single-Channel Detectors 1074
1.2.3.1 Basic Configurations 1074
1.2.3 Detector Implementation 1074
(2) Channelized Detectors 1076
1.2.3.2 Other Possible Feature Detector Configurations 1077
1.3 Performance and Strategies Assessment 1083
1.3.1 Communicator Modulation and Intercept Detectors 1083
1.3.2 Anti-Jam Measures 1087
1.3.3 Optimum LPI Modulation/Coding Conditions 1089
1.4 Further Discussion 1089
1.5 References 1092
Appendix 1A: Conditions for Viable Multichannel Detector Performance 1093
Chapter 2 Multiple Access 1096
2.1.1 Decentralized (Point-to-Point) Networks 1099
2.1 Networks 1099
2.1.2 Centralized (Multipoint-to-Point) Networks 1103
2.2 Summary of Multiple Access Tec hniques 1105
2.3 Spread-Spectrum Multiple Access with DS/BPSK Waveforms 1110
2.3.1 Point-to-Point 1110
2.3.2 Conventional Multipoint-to-Point 1113
2.3.3 Optimum Multipoint-to-Point 1116
2.4 Spread-Spectrum Multiple Access with FH/MFSK Wave forms 1123
2.4.1 Point-to-Point 1124
2.4.2 Conventional Multipoint-to-Point 1136
2.4.3 Optimum Multipoint-to-Point 1142
2.6 References 1148
2.5 Discussion 1148
Chapter 3 Commercial Applications 1158
3.1 Key Events in the Commercial Market 1160
3.2 The United States FCC Part 15 Rules 1160
3.2.1 Indoor Applications 1161
3.2.2 Outdoor Applications 1162
3.2.3 Direct Sequence Versus Frequency Hopping 1162
3.2.3.1 Conversion of Narrowband Radios 1163
3.2.3.2 Cost of Development and Products 1163
3.2.3.3 Performance 1163
3.2.4 Multipath and Diversity 1165
3.2.5 Results of The Part 15 Rule 1166
3.3 The Digital Cellular CDMA Standard 1169
3.3.1 Overview of the CDMA DigitalCellular System (IS-95) 1170
3.3.2 Comparison of IS-95, IS-54, and GSM 1172
3.4 A New Paradigm for Designing Radio Networks 1173
3.5 The Potential Capacity of Direct Sequence Spread Spectrum CDMA in High-Density Networks 1176
3.5.1 Data Versus Voice Applications 1179
3.5.2 Power Control 1179
3.5.3 Time Synchronization and Orthogonal Codes 1179
3.5.4 The Outbound Channel 1180
3.5.5 Frequency Reuse and Antenna Scctorization 1181
3.5.6 Narrowbcam and Delay-line Antennas 1181
3.6 Spread Spectrum CDMA for PCS/PCN 1182
3.6.2 S-CDMA Equivalent to Bit-Level TDMA 1183
3.6.1 Binary Orthogonal Codes 1183
3.6.3 A High-Density Voice PCS System 1186
3.6.3.1 Bit-Error Probabilities 1188
3.6.3.2 Computer Simulations 1191
3.6.3.3 Other System Issues 1192
3.6.3.4 Comparison with DECT 1193
3.7 Higher Capacity Optional Receivers 1194
3.8 Summary 1195
3.9 References 1196
Appendix 3A: Multipath and Diversity 1198
Appendix 3B: Error Bounds for Interference-Limited Channels 1208
Index 1215