BIT ERROR RATE FOR PRIVATE MOBILE RADIO (PMR) DUE TO...

BIT ERROR RATE FOR PRIVATE MOBILE RADIO (PMR)

DUE TO LIGHTNING ELECTROMAGNETIC FIELD RADIATION (LEMR)

MONA RIZA BINTI MOHD ESA

UNIVERSITI TEKNOLOGI MALAYSIA

BIT ERROR RATE FOR PRIVATE MOBILE RADIO (PMR)

DUE TO LIGHTNING ELECTROMAGNETIC FIELD RADIATION (LEMR)

MONA RIZA BINTI MOHD ESA

A thesis submitted in fulfillment of the requirements for the award of the degree of

Master of Engineering in Electrical – Electronic & Telecommunication

Faculty of Electrical Engineering Universiti Teknologi Malaysia

November 2005

iii

Dedicated to the dearest persons in my heart and the idol of my life

Puan Hajah Rosminah Mahmud

Encik Mohd Esa b. Ali

Mohd Ridhwan b. Mohd Esa

Mohd Redza Ezzaq b. Mohd Esa

Mohd Raffiq Azriq b. Mohd Esa

iv

ACKNOWLEDGMENT

I would like to express my highly gratitude and appreciation to:

1. Prof. Dr. Hussein Ahmad, for the supervision, assistance, encouragement and

advices that enable me to successfully complete this project with great

experience in this field, High Voltage and High Current. The support and full

attention that enable me to build up a good quality of a researcher in myself

2. Assoc. Prof. Dr. Ahmad Zuri, for the supervision, a lot of guidance to start

the simulation programming and advices in realizing and solving problem

arises.

3. Technician of IVAT that contributes lots of help and kindness in setting up

the high voltage and high current equipments in order to execute the

measurement and achieve the target of the project.

4. My best colleagues, for the ideas, moral supports and great indirect helps

during accomplishing this project.

5. My parents, for the love, care and understanding during the whole period of

completing the research and theses.

Last but not least, I would like to thank Allah for giving me motivation, strength

and guidance to successfully complete this research as planned.

v

ABSTRACT

The conceptual implementation to access the extend influence of lightning

electromagnetic radiation (LEMR) on mobile radio communication. Binary data has

been transmitted through a pair of Motorola Talkabout T5420 walkie-talkie with 14

channels and 38 eliminator codes and operates on 14 UHF Family Radio Service (FRS)

Frequencies. Two types of induced interferences which are high voltage and high

current experiment has been conducted in High Voltage Laboratory, Institute of High

Voltage and High Current, UTM. In order to achieve the implementation mention

above, a research has been conducted with the title of the project is “Bit Error Rate for

Private Mobile Radio (PMR) Due to Lightning Electromagnetic Field Radiation

(LEMP)”. The objective of the first part of the research is to determine whether the

lightning could produce the error of the bit in term of bit error rate in digital

communication. If there any errors, the research will continue to ascertain how much it

damage or influence the data. In optical communication, in practice, a low bit error rate

in the region 10-7 to 10-10 may be tolerated with pulse code modulation (PCM)

transmission. Although, in wireless communication, the receiver will face much higher

bit error rate due to the environment and nature phenomena such as rain drops, fogs,

thunderstorm and lightning.

vi

ABSTRAK

Konsep yang diimplementasi bagi mendalami kejadian yang dipengaruhi oleh

radiasi elektromagnet kilat (LEMR) ke atas perhubungan radio bergerak. Penghantaran

data binari melalui sepasang radio (Walkie-talkie) Motorola Talkablout T5420 dengan

14 saluran dan 38 penyahkodan serta 14 UHF FRS. Dua jenis gangguan tambahan iaitu

eksperimen menggunakan voltan tinggi and arus tinggi ke atas talian penghataran telah

dijalankan di makmal voltan dan arus tinggi, Institut Voltan dan Arus Tinggi, FKE,

UTM ke atas talian penghantaran. Bagi merealisasikan implementasi yang tersebut,

kajian yang bertajuk “Bit Error Rate for Private Mobile Radio (PMR) Due to Lightning

Electromagnetic Field Radiation (LEMP)” telah dijalankan. Tujuan utama kajian ini

adalah untuk melihat samada kilat akan menpengaruhi atau memberi kesan ke atas

komunikasi digital dalam bentuk kadar ralat bit (bit error rate). Jika terdapat ralat, kajian

diteruskan bagi memantau sejauhmana kerosakan pada data, secara praktikalnya, kadar

ralat bit amat rendah iaitu antara 10-7 hingga 10-10 yang mungkin boleh diterima dengan

penghantaran menggunakan pemodulatan kod denyut (PCM). Walaubagaimanapun,

dalam perhubungan tanpa wayar, bahagian penerima isyarat terpaksa berhadapan

dengan kadar ralat bit yang lebih tinggi disebabkan persekitaran dan fenomena alam

semulajadi seperti hujan, kabus, ribut dan kilat.

vii

TABLE OF CONTENTS

Title Page i

Declaration ii

Dedication iii

Acknowledgement iv

Abstract v

Abstrak vi

Table of Contents vii

List of Tables xii

List of Figures xiii

List of Symbols xvi

List of Abbreviations xviii

List of Appendices xx

CHAPTER TITLE PAGE

1 INTRODUCTION 1

1.1 General 1

1.2 Objective of Research 2

1.3 Research Scopes 3

1.4 Research Methodology 4

1.4.1 Flow Chart 4

1.4.2 Methodology 4

viii

2 FREQUENCY SHIFT KEYING (FSK) SIGNAL 6

2.1 Introduction - Passband Data Transmission 6

2.2 Coherent Fsk (Frequency Shift-Keying) 6

2.2.1 Problems with Coherent Detection 8

2.3 Non Coherent FSK 9

2.4 Signal Model 10

2.5 Sampling 10

2.6 Spectrum of Sampled Signals 11

2.7 Nyquist Sampling Theorem 12

2.8 Spectrum Representation of Signals 13

2.10 Free Space Loss 16

3 BIT ERROR RATE 17

3.1 Fundamental Concepts and Measurement Issues 17

3.1.1 Noise and BER 18

3.1.2 Quantization Errors 19

3.1.3 Q Function 19

3.1.4 Probability of Error (POE) 21

3.1.4.1 Probability of Error-Single Observation 21

3.1.4.2 Probability of Error – Multiple Observations 23

3.1.5 Factors Affecting BER 24

3.1.6 BER Measurement 24

3.1.7 How to Use BER Data? 25

3.2 Previous Research of BER 26

ix

4 LIGHTNING ELECTROMAGNETIC FIELD 28

4.1 Lightning Process 28

4.1.1 Type of Lightning Strike 30

4.1.2 Electromagnetic Pulse (EMP) 31

4.2 Modelling of Electromagnetic Fields 34

4.3 Previous Study of Lightning 40

5 MEASUREMENT AND EFFECT OF HIGH VOLTAGE AND

HIGH CURRENT OVER DATA TRANSMISSION 41

5.1 General 41

5.2 Experimental Set up 42

5.2.1 Introduction 42

5.2.2 Walkie Talkie as the Transmitter and Receiver 44

5.2.2.1 Frequency Channel Allocation 45

5.2.2.2 Transmitter 46

5.2.2.3 Receiver 48

5.3 First Experiment – Impulse Voltage Generator (IGV) 49

5.3.1 Impulse Voltage Generator (IVG) 50

5.3.3.1 Function 51

5.3.3.2 Experiment and Measurement 53

5.4 Second Experiment – Recloser Test Set (RTS) 54

5.4.1 Experiment and Measurement 56

x

6 RESULTS AND ANALYSIS 58

6.1 Generation of fsk signal 58

6.2 Result of Received Signal 62

6.2.1 Without Lightning (No High Voltage and High Current

Induced) 62

6.2.2 High Voltage – Using IVG 63

a) 170kV 63

b) 400kV 63

6.2.3 High Current – Using RTS RCL19 64

a) 200A 64

b) 440A 64

c) 650A 65

d) 720A 65

e) 850A 66

f) 1500A 66

g) 2000A 67

6.3 Analysis of Received Signal 67

6.3.1 No Lightning Condition 67

6.3.2 High Voltage – Using IVG 68

6.3.3 High Current – Using RTS RCL19 69

7 DISCUSSIONS AND CONCLUSIONS 70

7.1 Discussion 70

7.1.1 High Voltage Experiment 70

7.1.2 High Current Experiment 71

7.1.3 Overall Experiments 72

7.2 Conclusion 74

xi

8 REFERENCES 75

APPENDICES 78

APPENDIX A – IMPULSE VOLTAGE GENERATOR 78

APPENDIX B – OPERATING SPECIFICATION RECLOSER

TEST SET 95

xii

LIST OF TABLES

TABLE TITLE PAGE

Table 4-1 Lightning Return Stroke Data 33

Table 5-1 Frequency allocation or channel information of

the radios 46

Table 7-1 Total delay of every packet received at the

receiver 73

xiii

LIST OF FIGURES

FIGURE NO. TITLE PAGE

2-1 Frequency shift keying (fsk) signal with input

11100110011001100 7

2-2 Receiver structure of FSK signal 8

2-3 Coherent detection for X1(t) 8

2-4 Non coherent receiver structure 9

2-5 Sampling process 11

2-6 Amplitude spectra of a signal before and after sampling 12

2-7 Time domain representation of signal 14

2-8 Signal is represent in frequency domain 15

2-9 Frequency domain representation as T approaches infinity. 16

3-1 Probability of error under the graph 22

3-2 Schematic diagram of equipment for propagation measurements 26

3-3 Schematic Diagram of equipment for BER measurement using

phase-locked oscillator 27

4-1 Charge Separation 29

4-2 Stroke Channel Electromagnetic Pulse (EMP) 32

4-3 Geometry of straight vertical lightning channel of height H used to

calculate the EM field at a point above a perfectly conducting

ground 36

5-1 Overall view of research 41

5-2 Overall view of the experiment 44

xiv

5-3 Walkie-talkie Motorola Talkabout T5420 45

5-4 (a) Modification of handsfree into transmission line cable

connecting with the stereo jack 47

(b) Cable connected to the microphone of the radio 47

(c) Cable connected to the output port (speaker port) 47

(d) Actual connection of transmitter and base station 47

5-5 (a) Modification of handsfree into transmission line cable

connecting with the mono jack 48

(b) Cable connected to the speaker of the radio 48

(c) Cable connected to the input port of the computer

(microphone port) 48

(d) Actual connection of the receiver and the base station 48

5-6 (a) The plan view of the high voltage experiment layout 49

(b) The side view of the high voltage experiment layout 50

5-7 Impulse Voltage Generator (IVG) 50

5-8 (a) Basic diagram 52

(b) Basic diagram with parallel spark gaps 52

(c) Trigger range 53

5-9 Recloser Test Set (RTS) – RCL 19 54

5-10 (a) The plan view of the high current experiment layout 55

(b) The front view of the high current experiment layout 56

6-1 Sequence of 10 binary bits that has been transform to fsk signal 59

6-2 Sequence of 1000 bits binary data 60

6-3 Sequence of 1000 bit of binary data in the form of fsk signal 60

6-4 Frequency domain representation that used to differentiate two

different frequencies in figure 6-3 above 61

6-5 Time and frequency domain of received signal when no lightning

condition 62

6-6 Received signal when 170kV is induced to the transmitted signal 63

6-7 Received signal when 400kV is induced to the transmitted signal 63

6-8 Received signal when 200A is induced to the transmitted signal 64

xv







xvi

LIST OF SYMBOLS

x (t) - Frequency shift keying (FSK) signal

x0 (t) - FSK signal when bit is 0

x1 (t) - FSK signal when bit is 1

t - Time domain representation

A - Amplitude of cosine signal

f1 - Upper frequency

f0 - Lower frequency

Tb - Time interval

S, s - Sequence of binary bit

y (t) - Original signal including noise

n (t) - Noise signal

rb - Bit rate

n0 - Noise at time n (t0)

N0 - Noise power at t0

x(n) - Discrete-time signal

n - Number of discrete signal

x (t) - Set of impulse of the continuous-time signal

Ts - Discrete time interval

fs - Sampling frequency

fmax - Maximum frequency

X(f) - Aperiodic continuous-frequency

Ls - Free space loss

d - Distance in km

xvii

Q - Q function

Pe - Probability of error

Erf - Error function

Eb - Energy in one bit

C - Coulomb

kA - kiloampere

V - Volts

kJ - Kilojoules

s - Microsecond

Ms - Milisecond

E - Electric field intensity

B - Magnetic field intensity

J - Current density

c - Velocity of light

- Electric charge density

0 - Permeability of free space

0 - Permittivity of free space

A - Vector magnetic potential

- Scalar electric potential

H - Lightning channel height

z’ - Observation point height of EM field

fc - Carrier frequency

m - Meter

cm - Centimeter

Hz - Hertz

kHz - kilo Hertz

MHz - Mega Hertz

GHz - Giga Hertz

Cos - Cosine

xviii

LIST OF ABBREVIATIONS

A/D - Analog to Digital

ASK - Amplitude Shift Keying

BER - Bit error rate

BW - Bandwidth

CPFSK - Continuous Phase FSK

DPSK - Differential PSK

EM - Electromagnetic

EMP - Electromagnetic Pulse

FM - Frequency Modulation

FRS - Family Radio Service

FSK - Frequency Shift Keying

FS - Fourier Series

FT - Fourier Transform

HC - High Current

HEF - Horizontal Electric Field

HV - High Voltage

IF - Intermediate Frequency

IVG - Impulse Voltage Generator

LEMP - Lightning Electromagnetic Pulse

LEMR - Lightning Electromagnetic Radiation

LOS - Line of Sight

pdf - Probability Density Function

PMR - Private Mobile Radio

xix

POE - Probability of Error

PRBS - Pseudo random Binary Sequence

PSK - Phase Shift-Keying

PSTN - Public Switch Telephone Network

PTT - Push to Talk

QPSK - Quadrature PSK

QAM - Quadrature Amplitude

RTS - Recloser Test Set

UHF - Ultra High Frequency

xx

LIST OF APPENDICES

APPENDIX TITLE PAGE

A Impulse Voltage Generator 78

B Operating Specification Recloser

Test Set 95

CHAPTER 1

INTRODUCTION

1.1 General

Wireless communication technology has developed and more reliable in order to

communicate with other people around the world. In transferring the data from one end

to the other end, especially in wireless and mobile data transmission, the expected data

at the receiver should be the same as from the transmitter. Otherwise, the data will not

be classified as a reliable data.

However, the development of this technology is still unable to preserve their

reliability from several natural phenomena such as rain drops, storm and lightning

effects. In telecommunication, the sequence of rain on the microwave system at a

particular frequency is more critical especially for the countries located in tropical and

equatorial region (Din J. et. al, 2003) and so as lightning.

Lightning is a natural prodigy that is of great attention to human being because it

annihilating deformities to the equipment and installations. It integrated the formation of

high flashing of light and thunder sounds. In the early year, some primitive people

2

lightning were assigned to myths and superstitious. The first person endeavoured that

lightning is an electrical phenomenon was Sir Benjamin Franklin (Golam Sorwar,

1997).

Lightning plays a role as a major natural force of electromagnetic radiation and

the ability of transmitting data to the receiver become unreliable. A lot of amendments,

improvements, adjustments and alterations are to be made over the affected data in order

to make it become reliable and as the same as has been transmitted. A lot of research

and experiment has been done to conserve the data during the transmission after it being

influenced by this kind of natural prodigy. Therefore, a reliable and dependable data can

be accumulated at the receiver.

1.2 Objectives of Research

The objectives of this research are as follows;

1. To ascertain and prove whether lightning can contribute to BER in digital

communication.

2. To determine which of the lightning electromagnetic field components cause

maximum data corruption and deterioration.

3. To model the lightning interaction model with the data transmission using

electromagnetic theory.

3

1.3 Research Scopes

In order to ensure an accurate and reliable transmitted data, persistency and

consistency of data detector or receiver need to be clearly studied. The measurement of

bit error rate (BER) is a step towards the development of a reliable and error-free data

receiver. This research is to study the interaction between the electromagnetic field

produced by the lightning and the electromagnet field existed when transmitting signal

to the other end. Therefore, it is important to know which type of lightning is extremely

hazardous to the signal or data during the transmission. For that reason, it is required to

develop an electromagnetic modelling regarding the lightning interaction with the data

transmission. Besides, bit error rate (BER) during lightning strike activities for private

mobile radio will be measured. Two experiments has been conducted which involved

the use of a high voltage low current equipment and a high current low voltage

equipment. The first experiment, using impulse voltage generator (IVG) and the second

experiment using recloser test set. A pair of walkie-talkie at frequency from

925.130MHz to 935.430MHz Motorola T5420 was used in this experiment.

4

1.4 Research Methodology

1.4.1 Flow chart

Literature Review

Cable Input/output modification

1.4.2 Methodology

From the chart above, it can be described in detail as below:

1. Literature study related to this topic. The topic is divided into two diverse topics

which are bit error rate and lightning electromagnetic field fundamentals.

Data transmission & Collecting

Walkie-talkie

BER calculation and comparison(Matlab programming)

Analysis

Walkie-talkieset-up for set-up for

measurement inH.C. Lab

measurement inH.V. Lab

5

2. A sequence of binary data is generated using Matlab software and been

transform into frequency shift keying (fsk) signal before it can be transmitted

into the air interface.

3. A pair of walkie-talkie will be used in order to transmit and receive data;

therefore a pair of cable is going to be utilized in the experiment. The cable is

modified from the walkie-talkie handsfree that it possible to be connected into

the input and output port of the computer.

4. Experimental Setup - Two types of experiment will be conducted that are using

two main different equipments:

a. High voltage equipment – Impulse Voltage Generator (IVG) in High

Voltage Laboratory

b. High current equipment – Recloser Test Set (RTS) RCL19 in High

Current Laboratory

5. Signal is ready to be transmitted. Layout of both experiments can be referred in

chapter 5. The position of radios must be in line of sight (LOS) in order to ensure

there is no obstacle along the transmission path. Data is collected at the end of

the transmission path, receiver.

6. Several data starting with no lightning condition, high voltage values and high

current values. Received data or signal than be stored in the base station

(computer) and analysis will be done at the end of measurement.

7. All signals in the base station will actuate several simulation processes in order

to identify bit error rate. Bit error of the received signal will be calculated using

Matlab software. Other analysis will also be executed to determine the effect of

lightning strike to the transmitted signal through air interface.

74

unavailability of insulator to insulate the IVG. The results have found that no error or

loss of bit has been identified and not much of delay been exposed. Maximum delay of

received signal compared to no lightning data transmission is 2.0ms.

For the second experiment, it can be concluded that 8 has been analyzed started

with 200A, 440A, 650A, 720A, 850A, 1100A, 1500A and 2000A. From the results, loss

of bit has been identified at the current value of 440A, 850A and 2000A. Total bit loss

for those three current values is 25 bits or 0.025% loss out of 1000 bits of binary data.

Furthermore, delay of received signal in high current experiment has also been exposed

compared to no lightning condition. Minimum delay of received signal (for no lightning

condition) is 18.0ms. Maximum delay of received signal compared to original

10seconds data is 29.2ms. Maximum delay of received signal compared to no lightning

condition is 11.2ms

As the final conclusion, in telecommunication nowadays, an accurate data

transmission is the most expected in developing countries. In this proposal, literature

reviews of the effect of lightning electromagnetic field radiation to the mobile data

transmission have been presented. The results of the research can be used as the basis

for improving the performance of mobile transmission system especially in environment

where there are high lightning activities. This is can be executed by proper placing of

microwave repeater towers on hilly area which are less prone to lightning strikes.

REFERENCES

1. Rahayu, Y., Din, J. and Tharek,A.R., “23GHz Tranceiver System Design For

Point-to-Point Microwave Link”, 4 th National Conference on

Telecommunication Technology Proceedings, Shah Alam, Malaysia, 2003.

2. A. Z. Sha’ameri, Advance Digital Communications class notes “Passband

Data Transmission”.

3. A. Z. Sha’ameri, Advance Digital Signa l Processing class notes “A Review of

Signals and Systems”.

4. A. Z. Sha’ameri, Advance Digital Signal Processing class notes “Random

Signal Principles”.

5. http://dictionary.reference.com/search?q=bit error ratio or bit error rate (BER)

, 15th May 2004.

6. Gary Breed, “Bit Error Rate: Fundame ntal Concepts and Measurement

Issues”, High Frequency Electroni cs, 2003 Summit Technical Media, LLC

7. Velasco, J. B., “Improved FFSK Mobile Data Transmission’, 1998.

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Mobile Data Transmission”, IEEE Tran sactions on Communications, Vol. 37,

No. 4, April 1999.

9. Tharek, A.R. and McGeehan, J. P., “I ndoor Propagation and Bit Error Rate

Measurements at 60GHz Using Ph ase-Locked Oscillators”, 1988.

10. Tharek, A.R. and McGeehan, J. P., “Propagation and Bit Error Rate

Measurements within Buildings in the Millimetre Wave Band About 60GHz”,

1988.

76

11. R. Heiberger, T. Hoshida, S. Watanabe and H. Onaka, “BER Estim ation in

Optical Fibre Transmission System Employing All-Optical 2R Regenerators”,

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12. Sorwar Hossain, Md. Golam, “Analysis of Induced Surges on Overhead

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Lightning Activity”, Lightning Elim inators And Consultants, Inc. Boulder,

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14. A.M.A. Baker, M.S. Alam, M. Tanrioven, H.B. Ahmad, “Electrom agnetic

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– 415, 1983.

18. Nucci, C. A., F. Rachidi, M. V. Ianoz, and C. Mazzetti, “L ightning-Induced

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19. Chen Yuzhou; Liu Shanghe; W u Xiaor ong and Zhang Feizhou, “Sim ulation of

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21. Chunshan Yang and Bihua Zhou, “Calculati on of Electromagnetic Fields Very

Close to the Lightning”, IEEE Transac tion on Electromagnetic Compatibility,

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