DEVELOPMENT OF AF RELAY USING USRP PLATFORM FOR INDOOR

MARDIAH BINTI MORSIN

A project report submitted in partial fulfilment of the

requirements for the award of the degree of

Master of Engineering (Eletrical-Electronics & Telecommunications)

Faculty of Electrical Engineering

Universiti Teknologi Malaysia

JANUARY 2015

v

Specially dedicated to my beloved husband, Mak and Ayah

Thanks for all of your support.

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ACKNOWLEDGEMENT

Assalamualaikum;

I want to express my full appreciation to my supervisor, Dr. Leow Chee Yen

for the guidance, commentary and encouragement. His support makes the thesis can

be completed.

I am very thankful to my classmate, Nur Fatehah and Muhammad Rushidi for

their advices and assistance while preparing this research. Not to forget, NI support

team specially, Mr Alan and Miss Laila. Thanks for the supportive assistance on

LabVIEW.

Finally, to all my family members and my sons, Fateh, Khawarizmi and

Diha. Seeing your face every day encourage me to finish my thesis successfully.

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ABSTRACT

The increasing customer demand in broadband mobile wireless

communication technology leads to the introduction of the relay. Relay is able to

increase the capacity and coverage between base station and mobile user. There are a

lot of benefits that motivate the usage of relay, including reducing the power used at

base station and extending coverage area. Existing literature on relay focuses mainly

on simulation, with no measurement validation. This research therefore aims to

develop a prototype of Amplify-and-Forward (AF) relay using software defined

radio. The proposed relay is developed using LabVIEW software and programmed

on NI-USRP 2922 software defined radio platform. Measurement is performed

indoor and the signal strength or receive power at the mobile user with and without

relay is recorded. The result shows that the receive power performance and signal-to-

noise ratio (SNR) at the user improve 23% when the AF relay is deployed, as

compared to direct link point to point transmission without relay. As a future work,

the proposed relay can be further studied in outdoor environment and MIMO

antenna configuration to determine the receive power performance in line-of-sight

area.

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ABSTRAK

Permintaan pelanggan yang meningkat terhadap perkhidmatan jalur lebar

untuk sistem komunikasi tanpa wayar telah memacu kepada pengenalan relay. Relay

adalah satu teknik yang digunakan untuk meningkatkan penghantaran isyarat

kapasiti antara Stesen Penghantar dan Penerima. Terdapat banyak faedah yang

mempengaruhi penggunaan relay termasuk penghantaran kuasa yang kurang

digunakan di Stesen Penghantar, lanjutan perlindungan yang tinggi dan lain-lain.

Kajian ini dibuat untuk mengkaji pembangunan Amplify and Forward (AF) relay

bermula dari Stesen Penghantar, relay AF dan akhirnya kepada Penerima. Ia

dibangunkan dengan menggunakan perisian LabVIEW dan diprogramkan pada

perkakas NI USRP-2922. Pengujian dilakukan di dalam bangunan Makmal WCC

dan prestasi yang diukur adalah kekuatan isyarat atau Kuasa Penerima, Pr. Ia

menunjukkan bahawa menerima prestasi kuasa dan SNR bagi relay AF adalah lebih

baik berbanding dengan langsung titik pautan ke titik penghantaran dengan kenaikan

sebanyak 23%. Pada masa hadapan, pengujian Relay ini boleh dibuat di luar

bangunan serta menggunakan konfigurasi MIMO antenna untuk melihat prestasi

kuasa Penerima pada kawasan Had Penglihatan.

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TABLE OF CONTENTS

CHAPTER TITLE PAGE

DECLARATION ii

DEDICATION iii

ACKNOWLEDGEMENT iv

ABSTRACT v

ABSTRAK vi

TABLE OF CONTENTS vii

LIST OF TABLES x

LIST OF FIGURES xi

LIST OF ABBREVIATION xiv

LIST OF APPENDICES xv

1 INTRODUCTION 1

1.1 Introduction 1

1.2 Problem Statement 2

1.3 Research Objectives 2

1.4 Scope of Work 3

1.5 Thesis Outline 3

1.6 Summary of Work 4

2 LITERATURE REVIEW 7

2.1 Introduction 7

2.2 Amplify and Forward (AF) relay 7

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x

2.3 Orthogonal Frequency Division

Multiplexing(OFDM)

10

2.4 Software Defined Radio

2.4.1 Advantages of SDR

2.4.2 NI USRP-2922

2.4.3 LABVIEW

11

12

12

14

3 METHODOLOGY 15

3.1 Introduction 15

3.2 Project Overview 16

3.3 Development of AF relay, Source

and Destination

17

3.3.1 Source (Base Station)

3.3.2 AF Relay

3.3.3 Destination (User)

17

24

27

3.4 Deployment of the programming on-the-

shelf in the network scenario using NI

USRP-2922

31

3.5 Indoor measurement 32

3.5.1 Point to point direct transmission

setup

3.5.2 AF relay network setup

35

37

4 RESULT AND ANALYSIS 40

4.1 Introduction 40

4.2 Point to point direct transmission result 43

4.3 AF Relay network result 44

4.4 Point to point direct transmission and AF

relay network result

45

4.5 Receive Power versus SNR 47

4.6 Power ratio versus distance 48

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xi

5 CONCLUSION AND FUTURE WORKS 49

5.1 Conclusion

5.2 Future Work

49

49

REFERENCES 50

Appendices A-C 53-55

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xii

LIST OF TABLES

TABLE NO. TITLE PAGE

2.1 USRP Motherboards Component 13

xiii

LIST OF FIGURES

FIGURE NO. TITLE PAGE

1.1 Project Overview 4

1.2 Projects schedule for (a)phase one (b) phase two 5

2.1

2.2

AF Relay network

Software Defined Radio Block Diagram

8

11

3.1 Basic Communication System 15

3.2 Transmission using AF relay 17

3.3 Point-to-point direct transmission 17

3.4 Source (Base Station) block diagram 17

3.5 Flowchart of Source Programming 18

3.6 Front panel for transmission part (1) 21

3.7 Front panel for transmission part (2) 21

3.8 Front panel for transmission part (3) 22

3.9 Source VI block diagram (1) 23

3.10 Source VI block diagram (2) 23

3.11 Source VI block diagram (3) 23

3.12 Flowchart of AF relay 24

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3.13 Flowchart of AF relay 24

3.14 AF relay front panel 25

3.15 AF relay block diagram (1) 26

3.16 AF relay block diagram (2) 26

3.17 Destination block diagram 27

3.18 Flowchart of Destination Programming 28

3.19 Destination front panel (1) 29

3.20 Destination front panel (2) 30

3.21 Destination VI block diagram (1) 30

3.22 Destination VI block diagram (2) 31

3.23 Destination VI block diagram (3) 31

3.24 Transmitted signal display 32

3.25 Received signal with constellation diagram 32

3.26 Receive power measurement programming 35

3.27 Point-to-point direct transmission 36

3.28 Point to point direct transmission setup (a) actual setup

(b) layout design

36

3.29 AF relay network setup 37

3.30 AF relay network in actual measurement setup 38

3.31 Scenario 1 for AF relay network measurement setup 38

3.32 Scenario 2 for AF relay network measurement setup 39

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4.1 Waveform at the source while running LabVIEW

program.

40

4.2 Packet signal waveform and constellation diagram at

destination while point-to-point direct transmission

testing

41

4.3 AF relay waveform 42

4.4 Packet signal waveform and constellation diagram at

destination when AF relay measurement

42

4.5 Pythagoras theorem 43

4.6 Receive power for direct transmission versus distance 43

4.7 Receive power for AF relay versus distance 44

4.8 Receive power for the direct link and relay versus

distance

45

4.9 Receive power for the direct link and AF relay versus

SNR

47

4.10 Power ratio for direct link and AF relay versus distance 48

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LIST OF ABBREVIATIONS

AF - Amplify and Forward

OFDM - Orthogonal Frequency Division Multiplexing

DF - Decode and Forward

CF - Compress and Forward

BS - Base Station

NAF - Non-orthogonal Amplify and Forward

SAF - Slotted Amplify and Forward

DMT - Discrete Multitone Modulation

SISO - Single Input Single Output

MIMO - Multiple Input Multiple Output

USRP - Universal Software Radio Peripheral

FGPA - Field Programmable Gate Array

FFT - Fast Fourier Transform

IFFT - Inverse Fast Fourier Transform

VI - Virtual Instrument

PC - Personal Computer

WCC - Wireless Communication Centre

IQ - Quadrature signals

LOS - Line of Sight

NLOS - Non-Line of Sight

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LIST OF APPENDICES

APPENDIX TITLE PAGE

A On-the-shelf NI USRP-2922 53

B NI USRP-2922 Specification 54

C VERT900 Antenna Specification 55

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CHAPTER 1

INTRODUCTION

1.1 Introduction

The demand for data rate in wireless mobile communication increases

drastically in recent years [1]. The number of available data capacities and the

customer demand is not synchronous. The growth of the demand surpasses the

available capacity. In order to enhance the data rate and spectral efficiency [2],

relay has been proposed as the alternative.

Relay is a concept taken from a repeater. The main function of relay to is to

forward signals from base station to user and vice versa [3]. The relay is used to

increase the system cell edge coverage effectively [4]. By using relay, the data

transmission between Base Station and User at cell edge increases and the quality of

the channel improves [4]. The other benefit of the implementing a relay is that it can

reduce the power transmission consumption at the Base Station.

The relay can also be used to prevent the limitation of half duplex due to the

incompetence of current modems to receive and transmit data at the same frequency

and time. Another advantage of relay implementation is that it can avoid additional

cost to build another Base Station in the network. Relay can be installed anywhere

such as at the top of the lamp post or building because the relay hardware is of small

2

form factor. This will make the operation faster, flexible and cost effective for

operators [5].

1.2 Problem Statement

The followings are the problem statements for this project:-

i. The conventional fabricated relay is realised using fixed hardware. If

any changes or modifications are needed on the relay operation, the

whole set of hardware needs to be changed. This makes the

implementation of relay to become very costly.

ii. Previous studies are made in simulation environment rather than

based on field study in real operating environment. In this situation,

simulation result is an ideal case where it does not consider any kind

of practical circumstances, such as the environment factors, weather

and also the propagation conditions.

1.3 Research Objectives

The objectives of this project are:

i. to develop amplify-and-forward (AF) relay prototype using universal

software radio peripheral (USRP) platform and LabVIEW software,

ii. to measure the receive power of relaying network in comparison with

point-to-point direct transmission for indoor environment.

3

1.4 Scope of Work

The objectives of this project can be achieved within the scopes outlined. The

project uses the off-the-shelf NI USRP 2922 software defined radio to implement the

three-node network consists of the proposed AF relay, base station and mobile user.

The programming of the USRP is made using NI LabVIEW software.

The measurement is done indoor where the parameter considered is the

received power at the user. The measurement is done only for downlink transmission

and for single-input and single-output (SISO) antenna configuration only.

1.5 Thesis Outline

This thesis consists of five chapters. Chapter 1 gives an overview and the

introduction of the project.

Chapter 2 discusses the literature review on the concept of AF relay

techniques. The characteristics of AF and the purpose of choosing these techniques

are explained in details by comparing with previous studies. Other than that, the

concept of software defined radio (SDR) and the use of USRP is also discussed in

this chapter. In addition, the benefits of using AF relay are specified. Finally, the

concept of OFDM is also explained.

Chapter 3 contains the design methodology of the project. The design is

illustrated using flow charts to show the development of three main nodes which are

base station, AF relay and mobile user. Then, the measurement setup of the USRP

with a LabVIEW implementation is be discussed in this chapter.

In Chapter 4, the result and analysis of the point-to-point direct transmission

and AF relay assisted transmission are elaborated with the support of previous study

and also the theory of indoor propagation model.

4

Finally, Chapter 5 presents the conclusion of this project. The future work is

also elaborated in this chapter.

1.6 Summary of Work

The project flow illustrated in Figure 1.1. The project begins with the

literature review, followed by the simulation of the ergodic capacity versus SNR

using Matlab, for AF relay associated network in comparison with point-to-point

direct transmission. Next, the LabVIEW coding of a source, AF relay and destination

will be developed using basic transmission and receiver block diagram with the aid

of OFDM, Multiplexer, QAM Modulation, Matched Filter and some other coding’s.

The coding will be programmed onto the NI-USRP2922 FPGA system and the

downlink transmission will be tested. At first, the test runs on the equipment rack in

the laboratory. After the system is working as specified, it runs in real indoor and

environment. The parameter measured is the receiving power versus distance. The

final step is presentation and thesis writing.

Figure 1.1: Project overview

Start

Literature

Review

Matlab

Simulation

AF relay, Source &

Destination coding

developed

Success

No Yes

Indoor test run &

measurement

Presentation

Thesis writing

End

5

Figure 1.2 shows the Gantt chart of the project schedules for phase one and

phase two. The implementation of phase one was in semester one which covers

studying and understanding of literature review and also the determining the project

specification. Previous research related to this project and various types of relay

techniques is studied, including AF relay technique.

For phase two, the development of AF relay and also the Base Station

(source) and user (destination) coding using LabVIEW and NI-USRP 2922 are

performed. Then, indoor measurement of the receive power for relay assisted

network and point-to-point direct transmission are accomplished. Finally,

presentation and thesis writing are made after the development and measurement of

relay is completed.

PHASE ONE

MONTH FEBRUARY MARCH APRIL MAY

WEEK 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Research on

related topic

Literature

review

Methodology

study

Presentation

Report writing

(a)

6

PHASE TWO

MONTH SEPTEMBER OCTOBER NOVEMBER DECEMBER

WEEK 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Development

of AF relay,

BS and User

Indoor

measurement

Presentation

Thesis writing

(b)

Figure 1.2: Project schedule for (a) phase one (b) phase two

50

References

1 1. J. Cao, M. Ma, H. Li, Y. Zhang, Z. Luo, A Survey on Security Aspects

for LTE and LTE-A Networks, IEEE Communications Surveys &

Tutorials, Vol. 16, No. 1, 2014, pp. 281-302

2 2. W. Hong, J. Han, H. Wang, UL Performance Evaluation of Relay

Enhanced FDD LTE-Advanced Networks, Renesas

Telecommunication Technology,Beijing, China, 2011.

3 3. J. A. Aldhaibani, A.Yahya, R.B. Ahmad ,N. Omar, Z. G. Ali, Effect of

Relay Location on Two-Way DF and AF Relay for Multi-User System

in LTE-A Cellular Networks, IEEE Business Engineering and

Industrial Applications Colloquium (BEIAC), pp. 380-385, 2013.

4 4. D. Zhiguo, K. Ioannis, R. Beiyu, J. S.Thompson, W. Chao, Y. Sheng,

On Combating the Half-Duplex Constraint in Modern Cooperative

Networks: Protocols and Techniques, UK , 2011.

5 5. L. Ekkehard, R. Simone, R. Bernhard, Business Impact of Relay

Deployment for Coverage Extension in 3GPP LTE-Advanced, Nokia

Siemens Networks, Munich, Germany, 2009

6 6. W. Zhang, U. Mitra, M. Chiang, Optimization of Amplify-and-Forward

Multicarrier Two-Hop Transmission, IEEE Transactions On Comm.,

pp. 1434-1445, May 2011.

7 7. S.Yang, J. C. Belfiore, Towards the Optimal Amplify-and-Forward

Cooperative Diversity Scheme, IEEE Transactions On Information

Theory, pp. 3114-3126, Sept. 2007.

8 8. T. Cover, A. E. Gamal, Capacity theorem for the channel relay, IEEE

Transactions On Communications, vol. IT-25, pp. 575-584, 1979.

9 9. P. Popovski, H. Yomo, Physical Network Coding in Two–Way

Wireless Relay Channels, cs.IT, July 2007.

1 10. Y. Liu, M. Tao, An Optimal Graph Approach for Optimizing OFDMA

Relay Networks, IEEE ICC 2012 - Wireless Communications

Symposium, pp. 4277-4281, 2012.

1 11. W. Wang, R. Wu, Capacity Maximization for OFDM Two-Hop Relay

51

System With Separate Power Constraints, IEEE Transactions On

Vehicular Technology, Vol. 58, NO. 9, pp 4943-4954 Nov. 2009.

12. H. Bo, F. Xuming, Z. Yue, C. Yu, H. Rong, Dynamic Energy Saving

Subcarrier, Bit and Power Allocation in OFDMA Relay Networks,

China Communications Magazines, pp. 79-87, April 2013.

1 13. J. Dohl, G. Fettweis, Evaluation of Estimation and Mitigation

Algorithms for Nonlinearly Distorted OFDM Signals on a SDR

Platform, IEEE 13th International Workshop on Signal Processing

Advances in Wireless Communications (SPAWC), pp.535-539, 2012.

1 14. A. Marwanto, M. A. Sarijari, N. Fisal, S. K. S. Yusof, R. A. Rashid,

Experimental Study of OFDM Implementation Utilizing GNU Radio

and USRP – SDR, Proceedings of the 2009 IEEE 9th Malaysia Intern.

Conf. on Comm.”, pp.132-135. Dec.2009.

1 15. S. Venkatachalam, T. Manigandan, B. Priyavadhana, Implementation

of Orthogonal Frequency Division Multiplexing(OFDM) Using

Software Definable Radio (SDR) Platform, International Conference

on Computational Intelligence and Multimedia Applications, pp.398-

405, 2007.

1 16. M. Tichy, K. Ulovec, OFDM System Implementation Using a USRP

Unit for Testing Purposes, 22nd International Conference

Radioelektronika, 2012.

1 17. M. K. Awad, X. Shen, OFDMA Based Two-hop Cooperative Relay

Network Resources Allocation, ICC, pp.4414-4418, 2008.

1 18. G. Calcev, J. Bonta, Opportunistic two-hop relays for OFDMA cellular

networks, IEEE, 2008

1 19. Amado Gutierrez, Gerardo Laguna, Paulino Mendoza, Victor Rangel,

Physical level design of an OFDM radio for digital communication

with a software defined radio(SDR) platform, IEEE, 2013.

2 20. H. G. Yeh, P. Ingerson, Software-Defined Radio for OFDM

Transceivers, IEEE, 2010.

2 21. X. Li, W. Hu, H. Yousefi’zadeh, A. Qureshi, A Case Study of A MIMO

SDR Implementation, IEEE 2008.

2 22. LabVIEW User Manual, National Intrument (NI), Part Number

52

320999E-01,April 2003.

2 23. L. Johnny, A Bidirectional Two-hop Relay Network Using GNU Radio

And USRP, University Of North Texas, August 2011.

2 24. H. Hassan, L. Pavel, O.F. Timothy, H. Jianhua, Practical Network

Coding for Two Way Relay Channels in LTE Networks, School of

Engineering Swansea University, U. K, 2011.

25. X. Liu, G. Qiu, F. Yu, Experimental Study of Cooperative

Communication Utilizing GNU Radio and USRP2, Shenzhen, China,

pp 2577-2580, 2012.

2

2

2

2

3

3

26. K. Wesołowsk, Application of MIMO and network coding in two-way

relaying applied in LTE, IEEE 21st International Symposium on

Personal Indoor and Mobile Radio Communication, pp. 619-624,

2010.

27. S. Kumar, B. Farhang-Boroujeny, S. Uysal, C. Ng, Microwave indoor

radio propagation measurements and modeling at 5 GHz for future

wireless LAN systems, Microwave Conference, 1999 Asia Pacific,

vol.3, pp. 606–609, 30 November-3 December. 1999.

28. J. Tarng and T. Liu, Effective models in evaluating radio coverage on

single floors of multifloor building, IEEE Veh. Technol. Conf., vol. 48,

pp. 782–789, 1999.

29. H. Zepernick and T. Wysocki, Multipath channel parameters for the

indoor radio at 2.4 GHz ISM band, IEEE Veh. Technol. Conf., vol. 1,

pp. 190–193, May 1999.

30. H.Hashemi, The indoor radio propagation channel, Prociding of

IEEE, vol.81, no.7, pp.943-968, July 1993.

31. K. J. A. Chisty1, S. M. A. Islam2, S. E. Ullah3, S. R. Sabuj,

Performance Evaluation of Multiple Amplify and Forward Relayed

Cooperative MIMO-OFDM System with Implementation of ZF-SIC

and MMSE-SIC Signal Detection Schemes, Communications in

Information Science and Management Engineering, Vol. 3 Issue. 9, pp.

448-454, Sept. 2013

32. H.Yichen, J.Yindi,S.Shahrom, SNR-Per-Unit-Power Optimization In

RelayNetworks, ICA SSP2013,IEEE, pp.4953-4957, 2013.