CONTENTS
ACKNOWLEDGMENT i
ABSTRACT ii
CONTENTS iii
LIST OF ABBREVIATIONS vi
LIST OF FIGURES viii
LIST OF TABLES xi
INTRODUCTION 1
1. DIRECT SEQUENCE SPREAD SPECTRUM 3
1.1. Overview 3
1.2. History of Spread Spectrum 3
1.3. DS-SS and CDMA 3
1.3.1. How DS-SS Works? 5
1.3.2. CDMA System 6
1.3.2.1 Illustrative Example of CDMA 8
1.4. Summary 9
2. ERROR CORRECTION CODING 10
2.1. Overview 10
2.2. Information and Coding Theory 10
2.3. Entropy and Information Rate 11
2.4. Channels and Mutual Information 11
2.4.1. Information Transmission over Discrete Channels 11
2.4.2. Information Channels 11
2.5. Shannon’s Theorem 12
2.6. Block Codes 13
2.6.1. Error-Control Coding 13
2.6.2. Error Detection and Correction 13
2.7. Cyclic Codes 14
2.7.1 Description of Cyclic Codes 14
2.8 Convolutional Codes 14
2.8.1 Linear Sequential Circuits 16
2.8.2 Polynomial Description of a Convolutional Encoder 16 2.8.2.1 Constraint Lengths 17 2.8.2.2 Generator Polynomials 17 2.8.2.3 Feedback Connection Polynomials 18 2.8.3 Trellis Description of a Convolutional Encoder 19
2.8.3 Convolutional Decoding 20
2.8.3.1 Soft Decision Decoding 20 2.8.3.2 Hard Decision Decoding 22
2.9 The Viterbi Algorithm 22
2.10 Summary 23
3. INTERLEAVING 24
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3.1 Overview 24
3.2 Impact of Interleaving 24
3.3 Types of Interleaving 26
3.3.1 Random Interleaver 27
3.3.2 Periodic Interleaver 28
3.3.2.1 Block Interleaver 28
3.3.2.1.1 General Block Interleaver 30 3.3.2.1.2 Helical Scan Interleaver 30 3.3.2.2 Convolutional Interleaving 31
3.4 Time Diversity and Interleaving 33
3.5 Interleaving Delay 33
3.5.1 Effect of Delays on Recovery of Conv. Interleaved Data 33 3.5.2 Combining Interleaving Delays and Other Delays 34
3.6 Summary 34
4. JAMMING 35
4.1 Overview 35
4.2 Jamming Signal 35
4.3 Communication system in jamming 35
4.4 Types of Jamming 37
4.4.1 Partial-Band Jamming Channel (CW Jamming) 37 4.4.1.1 DS-SS and Broadband Continuous Noise Jamming 37 4.4.1.2 DS-SS and Narrowband Jamming 39
4.4.2 Pulse Jamming Channel 40
4.4.2.1 Pulsed Jamming for DS-SS 41 4.4.2.2 Potential Effects of Pulsed Interference 42 4.4.2.3 Pulsed Interference Model 43
4.5 Summary 46
5. RESULTS AND ANALYSIS 47
5.1 Overview 47
5.2 Problem Analysis 47
5.3 Simulation Environment 49
5.2 Simulation Results and Analysis 50
5.6 Summary 54
CONCLUSION 55
REFERENCES 57
APPENDIX 59
Appendix A Matlab Code 59
Appendix B The Q-Function and its Relationship to the Error Function 68
Appendix C Simulation Results 71
Appendix C.1 The Influence of Changing SIR 71 Appendix C.2 The Influence of Changing the Frame Length 73
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