DEVELOPMENT OF COOPERATIVE RELAY USING UNIVERSAL SOFTWARE RADIO PERIPHERAL MUHAMMAD RUSHIDI SABIRIN A project master submitted in fulfilment of the requirements for the award of Master of Engineering (Electrical-Electronics & Telecommunications) Faculty of Electrical Engineering Universiti Teknologi Malaysia JANUARY, 2015
iii Specially dedicated to my mother Siti Aishah Omar and my father Sabirin Ikhsan also my brothers Mohammad Rashid, Mohammad Ridhuan and Mohammad Radzi who have encourage, guide and inspired me throughout my entire life. Hopefully, all the contributions are blessed by Allah S.W.T, The Mighty Creator.
iv ACKNOWLEDGMENT Alhamdulillah, I m really grateful to Allah S.W.T with his greatness and blessing for giving me the strength in accomplishing this project in needed period. I would like to extend my sincerest gratitude to my supervisor, Dr Bruce Leow Chee Yen for his assistance, guidance and patience throughout the work of completing this project report and the final year project. The suggestion and recommendation from him is so helpful to finish the project. Dedications to all my family members especially my beloved mother and father and also my brothers who were always be there with support, courage and help whenever I need them at most, I really always be thankful to them. Then, the last but not least are for my friends Kak Mardiah morsin and Nurfateha Othman who are helped me breakthrough this entire studies with rise and falls together, I do still appreciate your contribution and help.
v ABSTRACT To meet the demand for high speed data, wireless cellular system technology has grown in a steady pace. However, the wireless signals are still vulnerable to the multipath fading, shadowing and path loss, making the communication less reliable. Cooperative relay is a techniques to improve signal reliability by introducing a an additional node between source terminal and destination terminal to provide redundant path for data transmission. However, existing work of cooperative relay investigate performance through theoretically simulation only. The real world performance remains unknown because the lack of prototype for field testing and measurement. The focus of this work is therefore to implement the cooperative relay prototype using Universal Software Radio Peripheral (USRP) and LabVIEW platform. The relay prototype based on Amplify-and-Forward (AF) protocol has been developed. The performance in terms of bit error rate (BER) of the cooperative relay link is compared with the direct link without relay. The measurement is carried out in the indoor environment. Measurement results show that the cooperative relay significantly improves the signal reliability and extends the coverage distance if compared to direct communication without relay.
vi ABSTRAK Dalam usaha untuk memenuhi tuntutan untuk data berkelajuan tinggi telah menyebabkan perkembangan pesat dalam teknologi wayarles sistem selular akan tetapi isyarat wayarles masih terdedah kepada kesan pelbagai arah yang pudar, membayangi dan rendah kekuatan isyarat yang menyebabkan isyarat kurang diperolehi. Geganti Koperasi adalah teknik yang mampu meningkatkan kebolehpercayaan isyarat dengan memperkenalkan geganti pautan sebagai nod tambahan antara terminal sumber dan terminal destinasi. Walau bagaimanapun, kerja-kerja yang telah dibuat oleh penyelidik,dengan menyiasat prestasi relay koperasi melalui teori atau prototaip simulasi akan tetapi bahawa prototaip adalah penting dimana ia boleh diuji prestasinya sebelum dilaksanakan dalam persekitaran sebenar.fokus dalam kerja ini adalah untuk melaksanakan komunikasi koperasi berdasarkan Universal Perisian Radio Persisian (USRP) dan platform LabVIEW dalam persekitaran yang sebenar. Teknik relay berdasarkan Amplift-dan-Forward (AF) diimplikasikan pelaksanaanya. Prestasi perbandingan kadar ralat bit (BER) antara pautan geganti kerjasama dengan pautan langsung telah dinilai. Persediaan eksperimen dijalankan dengan senario yang berbeza dan dijalankan dalam kawasan persekitaran tertutup. Hasil keputusan menunjukkan pautan geganti koperasi dapat meningkatkan prestasi dari segi kebolehpercayaan isyarat dan liputan jarak lanjutan.
vii TABLE OF CONTENTS CHAPTER TITLE PAGE DECLARATION DEDICATION ACKNOWLEDGEMENT ABSTRACT ABSTRAK TABLE OF CONTENTS LIST OF TABLES LIST OF FIGURES LIST OF ABBREVIATIONS LIST OF SYMBOLS LIST OF APPENDIX ii iii iv v vi vii x xi xiii xv xvi 1 INTRODUCTION 1 1.1 Project Background 1 1.2 Problem Statement 2 1.3 Research Objectives 2 1.4 Scope 2 1.5 Thesis outline 3
viii 2 LITERATURE REVIEW 4 2.1 Introduction 4 2.2 Cooperative Relay 5 2.3 Amplify and Forward 6 2.4 Orthogonal Frequency-Division Multiplexing 7 2.5 Software Defined Radio 7 2.6 Universal Software Radio Peripheral 8 2.7 NI USRP 2922 Hardware 9 2.8 LabVIEW National Instrument Software 11 2.9 Related Work 12 3 METHODOLOGY 14 3.1 Introduction 14 3.2 First Phase of Direct Link Development 16 3.2.1 A Source Terminal 16 3.2.2 Destination Terminal 19 3.3 Second Phase Cooperative Relay Link Development 22 3.3.1 A Relay Terminal 22 3.3.2 Destination Terminal Aided By A Cooperative Relay Link 24 3.4 Performance Measurement 25 3.5 Indoor Measurement Setup 26 3.6 Hardware Configuration 29 4 RESULT AND DISCUSSION 31 4.1 Introduction 31 4.2 Experimental result and analysis 31 4.3 Outdoor propagation measurement 37
ix 5 CONCLUSION AND FUTURE WORK 39 5.1 Conclusion 39 5.2 Recommendation and future work 39 REFERENCES 40 APPENDIX A 42
x LIST OF TABLES TABLE NO. TITLE PAGE 3.1 Hardware s specification used for this project 29 3.2 Indoor measurement parameter setup 30
xi LIST OF FIGURES FIGURE NO. TITLE PAGE 2.1 (a) Direct Link Communication 5 (b) Relay Link Communication 5 2.2 Schematic representation of Amplify and Forward 6 2.3 Each subcarrier orthogonal to each other by overlapping 7 2.4 a) Conventional radio (b) SDR 8 2.5 NI USRP-2920 System Block Diagram 9 2.6 NI-USRP configuration utility for connecting of USRP to the host computer 10 2.7 NI USRP 2922 device 11 2.8 Transmitter and receiver module using the LabVIEW Modulation Toolkit 12 3.1 Flowchart of the project 15 3.2 Block diagram of source terminal 16 3.3 VI block diagram OFDM at source terminal 17 3.4 VI block diagram for source terminal 18
xii 3.5 The front panel of source terminal 18 3.6 Block diagram of destination terminal 19 3.7 VI block diagram OFDM at destination terminal 20 3.8 VI block diagram for destination terminal 21 3.9 The front panel of destination terminal 22 3.10 Block diagram of relay terminal 22 3.11 VI block diagram for relay terminal 23 3.12 The front panel of relay terminal 24 3.13 Block diagram of cooperative relay link at destination terminal 24 3.14 VI block diagram of cooperative relay assisted communication at destination terminal 25 3.15 VI block diagram of computing BER 26 3.16 (a) The layout of direct link (b) The direct link experiment setup 27 3.17 (a) The layout of cooperative relay link (b) The cooperative relay link experiment setup 28 4.1 The direct link result at 20 meter from source terminal 32 4.2 The cooperative relay link result at 20 meters from source terminal 32 4.3 Comparison of direct link and cooperative relay link using inbound frequency at 100 khz bandwidth 33 4.4 Comparison of direct link and cooperative relay link using inbound frequency at 200 khz bandwidth 34 4.5 Cooperative relay link using outbound frequency at 100 khz bandwidth 35 4.6 Comparison BER vs SNR for cooperative relay link with direct link 36 4.7 Verification of data measured with the theoretical calculation 37
xiii LIST OF ABBREVIATIONS 1G - First Generation 4G - Fourth Generations MIMO - Multiple Input and Multiple Output SDR - Software Defined Radio NI - National Instrument USRP - Universal Software Radio Peripheral BER - Bit Error Rate AF - Amplify & Forward OFDM - Orthogonal Frequency-Division Multiplexing SISO - Single Input Single Output LOS - Line of Sight N-LOS - Non Line of Sight enb - enhanced Node B UE - User Equipment DF - Decode & Forward QAM - Quadrature Amplitude Modulation PSK - Phase Shift Keying ADC - Analog to Digital Converter DAC - Digital to Analog Converter DSP - Digital Signal Process FPGA - Field Programmable Device Array
xiv FM - Frequency Modulation AM - Amplitude Modulation PM - Phase Modulation ASK - Amplitude Shift Keying FSK - Frequency Shift Keying PAM - Pulse-Amplitude Modulation QPSK - Quadrature Phase Shift Keying GMSK - Gaussian Minimum-Shift Keying MSK - Minimum-Shift Keying 2D - Two Dimensions 3D - Three Dimensions WARP - Wireless Open-Access Research Platform LTE - Long-Term Evolution PC - Personal Computer IP - Internet Protocol FFT - Fast Fourier transforms VI - Virtual Instrument SNR - Signal to Noise Ratio
xv LIST OF SYMBOLS db - Decibel m - meter Hz - Hertz
xvi LIST OF APPENDIX APPENDIX TITLE PAGE A Datasheet NI USRP 2922 43
1 CHAPTER 1 INTRODUCTION 1.1 Project Background The growing demand of data applications has led significant development in wireless communications. The development of cellular networks from first generation, 1G until the latest fourth generation, 4G is due to the demand in high speed data rate among the users. However, to provide an improvement of signal reliability and enhanced system capacity remains a challenge. This is due to various propagation effects like path loss, shadowing, multipath fading and interference. Multiple Input and Multiple Output (MIMO) is one of the approaches to improve the data rate and reliability. In MIMO, the receiver receives the combined signals from individual paths which are independently distributed in frequency, time and space. This technique is known as spatial diversity which can enhance the system performance. However, a higher cost is required to upgrade an existing base station with the multiple antennas for MIMO. On the other hand, wireless relay terminal offers improvement of signal reliability and cost efficiency whereby its deployment is not relying on wired backhaul. A relay is introduced in between source terminal, and destination terminal to provide redundant path known as the cooperative relay link for transmission. The conventional wireless system used a point-to-point link from the base station to the user equipment. This link is also known as a direct link. A relay can boost the signal reliability by combining the cooperative relay link and direct link.
2 1.2 Problem Statement The following are the problem statements for this project: (a) Most of the existing works on cooperative relay investigate the performance through theoretically simulation. The real world performance remains unknown because the lack of relay prototype for field testing and measurement. (b) The simulations usually fail to realistically capture the real world wireless signal propagation effects, which motivates the need of a testbed of practical relay to access the performance in actual environment. 1.3 Research Objectives The objectives of the project are: (a) to develop a cooperative relay testbed using Universal Software Radio Peripheral (USRP) and LabView platform software. (b) to measure the performance bit error rate (BER) performance of cooperative and direct communication in indoor environment. 1.4 Scope The scope of work is outlined in this section.this project covers the development of three-node network consists of source, destination and a relay. The cooperative relay technique used is amplify-and-forward (AF). Besides that, the modulation will be accessed using orthogonal frequencydivision multiplexing (OFDM) mode. Scenarios consists of source, destination and relay like single input single output (SISO) configuration, single relay network, the
3 line of sight (LOS) and non line of sight (N-LOS) environments are considered. Lastly, all the measurements perform on the downlink transmission. 1.5 Thesis Outline The structure of the report consists of five chapters. In Chapter 1, the introduction and overview of this project is stated.. In Chapter 2, the literature review on cooperative relay and AF relay and also the benefits of using SDR in developing of wireless system is highlighted. The hardware and software tools used in this project are discussed as well. The Related work about the cooperative relay based either on theoretical simulations and testbed measurements are reviewed in order to identify the research gaps. The methodology of the project is covered in the Chapter 3. In this chapter, the overview of the development USRP relay testbed is discussed. There are two phases in developing the testbed. The first phase of development starts with the direct link communication between the source and the destination. The second phase covers the cooperative relay development, where the relay node is introduced between the source and destination. The experimental setup and the configuration parameters of the project is explained and the measurements of BER performance is conducted in the indoor environment. In Chapter 4, the results of BER performance measurement of the direct link versus cooperative relay link communication is analysed. Discussion on whether the relay prototype meets the requirements of the project is made. Finally, in Chapter 5 a conclusion is drawn to summarise the main findings of this project. Potential future works is also suggested.
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