Air Force Institute of Technology AFIT Scholar Theses and Dissertations Student Graduate Works 3-2001 Using Direct-Sequenced Spread Spectrum in a Wired Local Area Network Robert J. Bonner Follow this and additional works at: https://scholar.afit.edu/etd Part of the Digital Communications and Networking Commons Recommended Citation Bonner, Robert J., "Using Direct-Sequenced Spread Spectrum in a Wired Local Area Network" (2001). Theses and Dissertations. 4570. https://scholar.afit.edu/etd/4570 This Thesis is brought to you for free and open access by the Student Graduate Works at AFIT Scholar. It has been accepted for inclusion in Theses and Dissertations by an authorized administrator of AFIT Scholar. For more information, please contact [email protected]. USING DIRECT-SEQUENCED SPREAD SPECTRUM IN A WIRED LOCAL AREA NETWORK THESIS Robert J. Bonner, First Lieutenant, USAF AFIT/GE/ENG/01M-02 DEPARTMENT OF THE AIR FORCE AIR UNIVERSITY AIR FORCE INSTITUTE OF TECHNOLOGY Wright-Patterson Air Force Base, Ohio Approved for public release; distribution unlimited 20010706 127 AFIT/GE/ENG/OlM-02 Using Direct Sequenced Spread Spectrum in a Wired Local Area Network THESIS Robert Joseph Bonner First Lieutenant, USAF AFIT/GE/ENG/OlM-02 Approved for public release; distribution unlimited The views expressed in this thesis are those of the author and do not reflect the official policy or position of the Department of Defense or the United States Government. AFIT/GE/ENG/OlM-02 Using Direct Sequenced Spread Spectrum in a Wired Local Area Network THESIS Presented to the Faculty of the School of Engineering and Management of the Air Force Institute of Technology Air University In Partial Fulfillment of the Requirements for the Degree of Master of Science in Electrical Engineering Robert Joseph Bonner, B.S. Electrical Engineering First Lieutenant, USAF March 2001 Approved for public release; distribution unlimited AFIT/GE/ENG/OlM-02 Using Direct Sequenced Spread Spectrum in a Wired Local Area Network Robert Joseph Bonner, B.S. Electrical Engineering First Lieutenant, USAF Approved: Major Rusty O. Baldwin Date Thesis Advisor /-> Major Richard A. Raines Date Committee Member «,-— Dr. Michael A. Temple Date Committee Member Acknowledgements I would like to express my sincere appreciation to my thesis advisor, Major Rusty Baldwin for his support and encouragement during the course of this thesis effort. His encouragement and keen insight helped me stay focused and get through some rather difficult hurdles to see this research to completion. I would also like to extend a special thanks to my committee members, Major Richard Raines and Dr. Michael Temple for their guidance and advice. I have relied heavily upon their support as well as the support of my fellow USAF and TUAF colleagues who assisted me during my research. Of all those who helped me, I owe my wife the greatest debt of gratitude. She was very supportive and encouraging throughout my AFIT experience. She bore the weight of taking care of me, our pets, and our home. Due to the workload and stresses associated with this assignment, it has presented a considerable challenge to the both of us. If not for her support and understanding, I could not have completed my studies. Robert Joseph Bonner m Table of Contents Page Acknowledgements in List of Figures ix List of Tables xi List of Abbreviations xii Abstract xiii I. Introduction 1-1 1.1 Background 1-1 1.2 Research Goal 1-2 1.3 Organization 1-3 1.4 Conclusion 1-3 II. Literature Review 2-1 2.1 Introduction 2-1 2.2 Communication Networks 2-1 2.3 OSI Reference Model 2-1 2.3.1 Communication Links 2-3 2.3.2 Medium Access Control 2-3 2.3.3 Network Performance 2-4 2.4 Wired and Wireless Networks 2-8 2.5 Carrier Sense Multiple Access With Collision Detection 2-9 2.5.1 Ethernet Operation 2-9 2.5.2 Ethernet Implementation Issues 2-11 iv Page 2.5.3 Physical Medium 2-12 2.5.4 Past Ethernet Performance Studies 2-13 2.5.5 Summary of Research in CSMA/CD Network Performance 2-16 2.6 Code Division Multiple Access 2-17 2.6.1 Spread Spectrum 2-17 2.6.2 DS/CDMA Transmission 2-17 2.6.3 CDMA Operation 2-20 2.6.4 CDMA Performance Studies 2-26 2.6.5 Current CDMA Implementations 2-31 2.6.6 Summary of DS/CDMA Research 2-31 2.7 Summary of CSMA/CD and DS/CDMA Research . 2-32 2.8 OPNET 2-33 2.8.1 Design Tool 2-33 2.8.2 Transceiver Pipeline 2-34 2.9 Summary 2-41 III. Methodology 3-1 3.1 Background 3-1 3.2 Problem Definition 3-2 3.3 Hypothesis 3-2 3.4 Goals 3-3 3.5 System Definition 3-3 3.6 Approach 3-3 3.7 System Boundaries 3-4 3.8 System Services and Performance Metrics 3-5 3.9 Parameters 3-7 3.9.1 System 3-7 Page 3.9.2 Workload 3-9 3.10 Factors 3-10 3.11 Exponential Distribution for Workload 3-10 3.12 Evaluation Technique 3-11 3.13 Models Used 3-12 3.14 OPNET Implementation of DSSS 3-12 3.14.1. Stage 2-Link Closure 3-14 3.14.2 Stage 3 - Channel Match 3-14 3.14.3 Stages 4 & 6- Transmitter and Receiver An- tenna Gain 3-15 3.14.4 Stage 7 - Received Power 3-15 3.14.5 Stage 9 - Multiple Access Interference Noise . 3-16 3.14.6 Stage 10 - Signal to Noise Ratio 3-19 3.15 Experimental Design 3-19 3.15.1 Regression Model 3-20 3.15.2 Verification and Validation of Models 3-21 3.16 Summary 3-22 IV. Results and Analysis 4-1 4.1 Verification and Validation 4-1 4.1.1 CSMA/CD 4-2 4.1.2 DS/CDMA 4-6 4.2 CSMA/CD Analysis 4-16 4.2.1 Throughput 4-16 4.2.2 Delay 4-19 4.2.3 Power 4-20 4.3 DS/CDMA Analysis 4-20 4.3.1 Throughput 4-20 VI Page 4.3.2 Delay 4-23 4.3.3 Power 4-25 4.3.4 Failure Point 4-25 4.4 System Comparison 4-26 4.4.1 Throughput 4-26 4.4.2 Delay 4-29 4.5 Summary 4-31 V. Conclusions and Recommendations 5-1 5.1 Goal 5-1 5.2 Results 5-1 5.3 Conclusions 5-1 5.4 Implications and Impact 5-2 5.5 Recommendation for Future Work 5-3 5.6 Summary 5-4 Appendix A. Model Analysis A-l Appendix B. Model Validation B-l B.l Normal Quantile-Quantile Plot B-l B.2 R2 Linearity Test B-l B.3 Residual Scatter Plots B-2 B.4 Normality Test Results B-2 B.5 Scatter Plot Test Results B-4 Appendix C. DS/CDMA Failure Point Prediction C-l Appendix D. Pipeline Stage Code D-l Bibliography BIB-1 Vll Page Vita VITA-1 vni List of Figures Figure PaSe 2.1. Conceptualized Ethernet Operation 2-10 2.2. Basic DSSS System Model with BPSK Data Modulation . 2-18 2.3. Example Modulation and Demodulation of a DSSS Signal . 2-19 2.4. A CDMA Channel Model With K Users 2-20 2.5. Conceptual Cell Phone Communication Link 2-27 2.6. OPNET Radio Transceiver Pipeline 2-35 2.7. Multiple Areas of Collisions on Transmitted Packets 2-39 3.1. Simplified Diagram of Multiple Access Interference 3-17 4.1. Ethernet Station Verification Setup: 2 Stations 4-4 4.2. Ethernet Station Verification Setup: 4 Stations 4-4 4.3. Ethernet Validation Responses 4-7 4.4. Node Model of DSSS Transmitter 4-7 4.5. Node Model of DSSS Receiver 4-7 4.6. DSSS Jamming Verification 4-9 4.7. Traditional Radio BER, SNR, and Throughput Performance in the Presence of Jammer Interference 4-10 4.8. DSSS BER and SNR Mitigation of Jammer Interference . 4-11 4.9. Two Simultaneous Wireless Radio Communication Links . 4-12 4.10. DSSS Validation Comparison to Analytic Models 4-15 4.11. CSMA/CD Responses With Respect to Load 4-17 4.12. CSMA/CD Responses With Respect to Number of Stations . 4-18 4.13. DS/CDMA Responses With Respect to Load 4-22 4.14. DS/CDMA Responses With Respect to Number of Stations . 4-23 IX Figure Page 4.15. Comparison of DS/CDMA and CSMA/CD Responses Vs. Net- work Offered Load 4-27 4.16. Comparison of DS/CDMA and CSMA/CD Responses Vs. Num- ber of Stations 4-28 4.17. Comparison of DS/CDMA and CSMA/CD Mean Station Per- cent Throughput Vs. Load 4-29 B.l. Normal Q-Q Plot of the Delay Residuals B-3 B.2. Normal Q-Q Plot of the Throughput Residuals B-4 B.3. Scatter Plot of Residuals Vs. Experiment Number of Delay Responses B-5 B.4. Scatter Plot of Residuals Vs. Experiment Number of Through- put Responses B-6 B.5. Scatter Plot of Residuals Vs. Fitted Values of Delay Responses B-6 B.6. Scatter Plot of Residuals Vs. Fitted Values of Throughput Re- sponses B-7 C.l. Baseband BPSK Signal Spectrum C-l x List of Tables Table Page 2.1. RG-58 Cable Specifications 2-13 2.2. Three-Level Cross-Correlation Properties of Gold Sequences . 2-25 3.1.