INDOOR PROPAGATION PREDICTION AND...
Transcript of INDOOR PROPAGATION PREDICTION AND...
INDOOR PROPAGATION PREDICTION AND MEASUREMENTS WITHIN
MULTISTORY BUILDING FOR WIRELESS LAN APPLICATIONS
ABDUSAMEA I.A OMER
UNIVERSITI TEKNOLOGI MALAYSIA
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ACKNOWLEDGMENT
In the name of Allah, Most Gracious, and Most Merciful
Praise be to Almighty Allah (Subhanahu Wa Ta’ala) who gave me the
courage and patience to carry out this work. Pease and blessing of Allah be upon his
last prophet Mohammed (Sallulaho-Alaihe Wassalam) and all his companions
(Sahaba), (Razi-Allaho-Anhum) who devoted their lives towards the prosperity and
spread of Islam.
My deep appreciation and heartfelt gratitude goes to my supervisor,
PROF.DR THAREK BIN ABDUL RAHMAN for his kindness, constant endeavor,
and guidance and the numerous moments of attention he devoted through out this
work.
I extend my deepest gratitude to my close friend, Eng. Ibrahim Abuharba for
his encouragement and motivation. Also I would like to thank friends and stuff in
wireless communication center (WCC) for their help facilities and for providing
conductive working environment
Family support plays a vital role in the success of any individual. I would like
to convey a heartfelt thanks to my parents, brothers, and other family members
including all my uncles, ants and their families; their prayers and encouragement
always helped me take the right step in life.
A heartfelt gratitude and acknowledgement are due to the Libyan community
in UTM, Skudai for their kindness, care, valuable advices and cooperation, which
generates a similar environment as what I left.
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ABSTRACT
In recent years, the possibility of using radio for data and voice
communications inside the buildings has become an attractive proposition. A
prerequisite to the design of indoor radio communication systems is knowledge of
indoor propagation characteristics. These characteristics can be used to determine the
optimum location of the base station antenna for a desired coverage within a
building. Propagation prediction within buildings is made difficult by the occurrence
of various propagation phenomena which depend on specific building structures. In
this project the investigation for WLAN system is done for three different buildings
inside University of Technology Malaysia. The Site Ware Technology's site specific
propagation prediction tool is a three-dimensional (3-D) ray tracing code employing
modified shoot and bounce ray(SBR) method know as the Vertical Plane Launch
(VPL) will be used to predict indoor propagation effects with different building
structures to show the prediction of the path loss and the time delay spread for
WLAN system inside these buildings, also a comparison between the real time
measurements using AirMagnet software and the prediction using VPL software
has been done for verification and the AutoCAD tool with the help of Ms Excel, was
used to measure all the building's dimensions for highly accurate building database.
The results from both prediction and measurement are in form of numbers, so Matlab
has been used to present these outputs in 2D display. Finally, based on the evaluation
results, we provide a set of recommendations that might help to improve this work
and fulfill the indoor user requirements.
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ABSTRAK
Syak kebelakangan ini , penggunaan radio untuk komunikasi data dan suara
dalam bangunan telah menjadi suatu proposisi yang menarik . factor yang diperlukan
dalam rekaan sistem komunikasi radio dalaman adalah pengetahuan tentang karakter-
karakter perambatan dalaman . karakter- karakter ini boleh digunakan dalam
penentuan lokasi optima antena stesen asas bagi sesuatu , rangkuman dalam
bangunan yang diinginkan ramalan perambatan dalam bangunan menjadi sukar
dengan kejadian pelhagi fenomena perambatan yang bergantung kepda struktu
struktu spesifik bangunuan . dalam projek ini ,siasatan sistem WLAN dilaksanakan
untuk tiga bangunan yang berbeza dalam Universiti Teknologi Malaysia . alat
ramalan perambatan lokasi spesifik oleh site ware technology ialah tiga dimensi
(3D)”ray tracing “ kod yang menggunakam modifikasi “shoot” dan “bounce ray
“(SBR) cara yang juga dikenali sebagai “ Vertical Plane Launch” (VPL). la akan
digunakan dalam meramal efek-efek perambatan dalaman dengan pelbagai Stnrkuer
beugunan berbeza whtuk menunjukkan ramalan ″path loss″ dan ″time delay opread″
bagi sistem WLAN dalam bengunan serta perbandingan antara pengukuran sebener
menggunalcan software dilaksanakan untuk tujuan verifikasi. Dengan bantuan Ms
Excel, alat antocad digunakam untuk mengukur samua dimensi bengunan untuk
memperoleh dadbase bangunan yang dalam bentuk numbor-nombor. Oleh itu,
Matlab digunakan untuk menunjuklcan output-output ini dalam pameran secara 2D.
Akhir sekali dengan berpandutcan hasil-hasil evausasi, satu set cadangan membina
dalam meningkatkan kerja ini dan mencapai kehendak-kehendak pengguna dalaman
akan dibekalkan.
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TABLE OF CONTENTS
CHAPTER TITLE PAGE
DECLARATION ii
DEDICATION iii
ACKNOWLEDGEMENTS iv
ABSTRACT v
ABSTRAK vi
TABLE OF CONTENTS vii
LIST OF TABLES xi
LIST OF FIGURES xii
LIST OF SYMBOLS xv
LIST OF APPENDENCES xvii
1 INTRODUCTION 1
1.1 Overview 1
1.2 Problem Statement 2
1.3 Objective of the Project 2
1.4 Scope of the Project 2
1.5 Methodology of the Project 3
1.5.1 Site Survey 3
1.5.2 Data Collection of Multistory building
using AutoCAD 3
1.5.3 Excel Files 3
1.5.4 VPL Simulation 3
1.5.5 Real time measurement 4
1.6 Organization of the Thesis 6
2 LITERATURE REVIEW 7
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2.1 Wireless Local Area Network (WLAN) 7 2.1.1 Introduction 7 2.1.2 Benefits of Wireless LANs 7
2.1.3 Architecture of a Wireless LAN 8
2.1.3.1 Stations 8
2.1.3.2 Access Points (AP’s) 8
2.1.3.3 Wireless Clients 9
2.1.3.4 Basic Service Set 9
2.1.3.5 Independent Basic Service
Set
9
2.1.3.6 Infrastructure Basic Service
Set 9
2.1.3.7 Extended Service Set 10
2.1.3.8 Distribution System 10
2.2 IEEE 802.11 Standards 10
2.3 Indoor Radio Wave Propagation 12
2.3.1 Reflection: 13
2.3.2 Diffraction: 14
2.3.3 Refraction 15
2.3.4 Scattering 15
2.3.5 Indoor Path Loss 16
2.3.6 Free Space Los 16
2.3.7 Line of Site Path Loss 18
2.3.8 Obstructed Path Loss 19
2.3.9 Doppler frequency shift 20
2.3.10 Multipath and Fading Effects 22
2.3.11 Delay Spread 24 2.3.12 Raleigh Fading 25
2.3.13 Rician Fading 25
2.3.14 Related work 26
3 RAY TRACING SOFTWARE AND 30
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SIMULATION
3.1 Propagation Models 30
3.1.1 Two-Ray tracing Model 30
3.1.2 Vertical-Plane-Launch Method 32
3.1.3 Algorithm of Simulation Software 33
3.2 Databases for Simulation 35
3.2.1 Building database 35
3.2.2 Receiver Database 37
3.2.3 Building Interior Database Format 38
3.3 Simulation Command Input 39
3.4 Output of the Prediction Tool 40
4 RESULTS AND DISCUSSION 42
4.1 Over view 42
4.2 Output Result from VPL Software 42
4.2.1 Power and Delay Spread Output 43
4.2.2 Impulse Response Output 43
4.2.3 Ray Path Information Output
43
4.3 Measurements result using AirMagnet 47
4.4 Result Visualization 48
4.4.1 Path Loss and Time delay spread
Visualization for WCC 48
4.4.2 Path Loss and Time Delay Spread
For KOLEJ PERDANA 50
4.4.3 Path Loss and Time Delay Spread
For KOLEJ 11 MA7 building 59
4.5 Result Analysis 60
4.5.1 Path Loss and Time Delay Spread 60
4.5.2 Comparison between Prediction and
Measurement Result 61
5 CONCLUSION 63
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LIST OF TABLES
TABLE NO. TITLE PAGE
2.1 WLAN standards 12
2.2 2.4 GHz Signal Attenuation 20
2.3 Diffierent Between two types of ray tracing models 29
3.1 Part of WCC building database 36
3.2 Example of the receivers database 37
3.3 Interior building database 39
3.4 Simulation Command input 40
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LIST OF FIGURES
FIGURE NO. TITLE PAGE
1.1 AirMagnet Software with Laptop 4
1.2 Flow chart of the methodology 5
2.1 Access Point infrastructure 8
2.2 Wireless Local Area Network Architecture using an
Infrastructure BSS 10
2.3a Reflected Signal on partial reflective surface 13
2.3b Reflected Signal on perfect reflective surface 13
2.4 Diffraction of a Signal 14
2.5 Refracted wave 15
2.6 Scattered Wave front on an I-beam 16
2.7 Free Space Radiating Point Source 17
2.8 2.4GHz Typical Path Loss 18
2.9 Multiple Floors Indoor Path Loss 19
2.10 Doppler frequency shift effect 22
2.11 Multipath signal in indoor environment 22
2.12 Small Scale Fading 24
2.13 Impulse response and frequency transfer function of a
multipath channel. 24
2.14 Measurement system by “Symbol” 26
2.15 Signal level without pepole 27
2.16 Signal level with present pepole 27
2.17 Effect opening and closing the door 28
3.1 Two-Ray Model 31
3.2 Ray generation in horizontal plane (Liang and Bertoni
1998) 33
3.3 Flow chart of ray-tracing simulation based on the VPL 34
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method (Liang and Bertoni 1998)
3.4 Sample of the AUTOCAD Building map of WCC 36
3.5 AutoCAD Receiver location map 37
3.6 Command input simulation 41
4.1 Example of power and delay spread output 44
4.2 Example of impulse response output 45
4.3 Example of ray path information output 46
4.4 Example of AirMagnet measurement (Kolej Perdana) 47
4.5 Simulation Path Loss for Mobile Lab room (WCC) 48
4.6 Time delay spread for Mobile Lab room (WCC) 49
4.7 Simulation Propagation predictions Path Loss for
(WCC) 49
4.8 Time delay spread for WCC 50
4.9 Kolej Perdana First floor Path loss propagation
predication at 2400MHz Carrier Frequency 50
4.10 Kolej Perdana Second floor Path loss propagation
predication at 2400MHz Carrier Frequency 51
4.11 Kolej Perdana Third floor Path loss propagation
predication at 2400MHz Carrier Frequency 51
4.12 Kolej Perdana Forth floor Path loss propagation
predication at 2400MHz Carrier Frequency 52
4.13 Kolej Perdana Fifth floor Path loss propagation
predication at 2400MHz Carrier Frequency 52
4.14 Kolej Perdana Sixth Floor Path loss propagation
predication at 2400MHz Carrier Frequency 53
4.15 Kolej Perdana Seventh Floor Path loss propagation
predication at 2400MHz Carrier Frequency 53
4.16 Kolej Perdana All the seven Floors Path loss
propagation predication at 2400MHz Carrier Frequency 54
4.17 Kolej Perdana-One Floor Path loss propagation
predication at 2400MHz Carrier Frequency (Based on
assumption that the building is only one floor) 54
4.18 Kolej Perdana One Floor Path losses Comparison 55
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between 1 ray (blue) model and 2 ray model (red)
propagation predication at 2400MHz Carrier Frequency
4.19 Time delay spread for the First Floor Kolej Perdana 55
4.20 Time delay spread for the Second Floor Kolej Perdana 56
4.21 Time delay spread for the Third Floor Kolej Perdana 56
4.22 Time delay spread for the Fourth Floor Kolej Perdana 57
4.23 Time delay spread for the Fifth Floor Kolej Perdana 57
4.24 Time delay spread for the Sixth Floor Kolej Perdana 58
4.25 Time delay spread for the Seventh Floor Kolej Perdana 58
4.26 Time delay spread for All the Seven Floors Kolej
Perdana 59
4.27 Kolej 11 All the four Floors Path loss propagation
predication at 2400MHz Carrier Frequency 59
4.28 Time delay spread for all the four Floors Kolej 11 MA7 60
4.29 comparison between real-time measurements and
simulation for Kolej Perdana 61
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LIST OF SYMBOLS
WLAN - wireless local area networks
WCC - Wireless Communications Center
IEEE - Institute of Electrical and Electronic Engineering
ETSI - European Telecommunications Standards Institute
VPL - Vertical Plane Launch
Wi-Fi - Wireless Fidelity
LOS - Line of sight
OFDM - Orthogonal frequency division multiplexing
DSSS - Direct sequence spread spectrum
Pt - Transmitting power
Pr - Receiving power
Gt - Transmitter antenna gain
Gr - Receiver antenna gain
Ar - Effective aperture of antenna
λ - Wavelength
C - Velocity of light
dB - Decibels
θ - Incidence angle
f - Frequency
ht - High of receiver antenna
hr - High of transmitter antenna
A - Attenuation factor
ρ - Ground reflection coefficient
r1, r2 - Phase path distance along
h - Fresnel zone radius to the knife edge
oλ - Free space wavelength
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dΔ - Distance difference
1d - Distance from transmitter to obstacle
2d - Distance from transmitter to obstacle
τ - Delay spread
v - Speed of portable
fc - Carrier frequency
L - Path loss
L0 - Reference loss
Li - Floor loss factor
D - Distance
h(t) - Impulse response
nA - Amplitude of signal
nτ - Arrival time
nϑ - Arrival phase
iE - Received field amplitude
oE - Transmitting field strength
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LIST OF APPENDICES
APPENDIX TITLE PAGE
A WIRELESS COMMUNICATION CENTER SIMULATION DATABASES
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B KOLEJ PERDANA SIMULATION DATABASES 76
C KOLEJ 11 MA7 BUILDING SIMULATION
DATABASES
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D RAY TRACING PROPAGATION PREDICTION 104
E AIR MAGNET SOFTWARE
F AUTOCAD IMPLEMINTATION 130
CHAPTER 1
INTRODUCTION
1.1 Overview
The past decade has witnessed a phenomenal growth in wireless
communication. Indoor wireless communication - such as is associated with personal
communication (PCS) and wireless local- area networks (LANs) - is exploding
rapidly. The need for an efficient way to evaluate radio propagation in buildings is
increasing. It is also critical to optimize the locations of the base stations required to
ensure satisfactory system performance. Consequently, radio-propagation prediction
for indoor environments, which forms the basis for optimizing the location of the
base stations, has become an important research topic.
Indoor radio propagation is not influenced by weather conditions, such as
rain, snow, or clouds, as is outdoor propagation, but it can be affected by the layout
in a building, and especially by the use of different building materials. Owing to the
reflection, refraction, and diffraction of radio waves by objects such as walls,
windows, doors, and furniture inside the building, the transmitted signal often
reaches the receiver through more than one path, resulting in a phenomenon known
as multipath fading [1].
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1.2 Problem Statement
Wireless LAN have become widely spread over the last few years, it has been
one of the most significant research topics to investigate how radio wave’s propagate
inside office environments, since local objects like pillars, walls, doors and windows
may reduce the link performance of such low power systems.
The existing for indoor environments is that the signal propagated from the
transmitter antenna will experience many different signal transformations and paths
with a small portion reaching the receiver antenna. Awareness of this process will
assist the user to better understand radio performance limitations.
1.3 Objective
This project is aiming to predict and measure the signal strength of wireless
LAN in a multi storey building (Kolej Perdana) in the University Of Technology
Malaysia in order to Obtain best efficiency and coverage of indoor propagation for
wireless LAN systems.
1.4 Scope of project
To provide proper study of wireless LAN propagation signal in multi storey
building, in which the signals are traced , and to build the database of a multi storey
building by using AUTOCAD and MS EXCEL Software; the simulation results will
be Presented by using MATLAB software for visualizing; The prediction will be
done at a carrier frequency 2.4GHz (based on IEEE 802.11 b/g standards) the
simulated result will be compared with the real time measurements that obtained
using Air magnet software In order to Analyze the simulated result.
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1.5 Project Methodology
1.5.1 Site Survey
Site survey involved in locating the place to be measured. As initial stage of
this project Wireless Communication Center (WCC) in Universiti Teknologi
Malaysia was the first place to be tested.
In the second stage of this project (kolej perdana) will be our target in the
following sections the procedures that have been taken in order provide a good
evaluation of coverage are introduced.
1.5.2 Data Collection of Multistory building
Building data base was provided by WCC as DWG file (DraWinG) witch
will be imported to CAD so all the measurements of the building dimensions can be
obtained easily.
1.5.3 Excel Files
Upon having the dimensions of the multistory building with the help of
AUTOCAD the dimensions are entered into an excel file , after words a file.txt can
be generated to be imported to VPL .
1.5.4 VPL Simulation
Firstly selecting up the parameters for VPL such as increment angel between
successive rays, operating frequency (in our case 2.4 GHZ), fresnel zone width first
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and second zone, antenna type (in our case monopole) Secondly, simulation is
carried out and the outcome of the simulation is tested If no errors, the results can be
plotted by using MATLAB two of the most graphs that will be plotted are path loss
and time delay spread .
If error occurs, then simulation must be repeated by changing either the
parameters of the VPL or the TXT file that was generated by Excel.
1.5.5 Real time measurement
Figure1.1 AirMagnet Software with Laptop
With the use of Air Magnet software, real time measurements can be conducted to
measure the actual strength and path loss of the signal.
Once the real time test has finished a comparison will be done with the predicted
result, the comparison will be in terms of path loss and time spread delay Upon this
comparison, an analysis can be done to evaluate the tested positions for Access
Points and Receivers to be located for best coverage Final recommendations can be
made to improve the performance of the network.
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Compare between measured &
simulated results
Data Collection Using AutoCAD
NO
Result Analysis
Collecting parameters
Done
Measurements usingAir magnet software
Generate Excel files • Building database • Receiver point database • Interior building data base
YES Simulation Using VPL
Success
UPDATING DATABASE
Illustrate simulation result using "MATLAB"
Site Survey
Figure1.2 Flow chart of the methodology
For Simulation
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1.6 Organization of the Thesis
Chapter 1 contains some brief overview of WLAN systems In addition to this, the
problem statement , objective and the scope of the research have been described.
Finally, the flow chart of how the work of this project has been carried out was also
illustrated.
The literature review is performed in chapter 2. Some introduction about the
WLAN architecture and propagation paths and WLAN propagation mechanism are
introduced such as reflection, refraction, diffraction, delay spread and multipath
fading, the last part shows a summary of some related works.
Chapter 3 contains the some Propagation Models and brief explanation about
vertical plane launch method , the types of databases needed for the simulation are
described and some examples are provided also the outputs of the simulation
software are briefly described and the command input for the simulation software
have been provided.
Chapter 4 contains the results from VPL, result from AirMagnet software,
Visualization result in 2D by Matlab, in this chapter also include some analysis that
is done based on the wireless communication principles and fundamentals.
Finally, Chapter 5 contains the summary of the thesis and also includes some
suggestions for future work.