UNIVERSITI PUTRA MALAYSIA

HALID BIN AGIL

FK 2012 42

MITIGATION OF RAIN ATTENUATION IN EQUATORIAL REGION FOR MEASAT-2 AND MEASAT-3 USING ORBITAL DIVERSITY

MITIGATION OF RAIN ATTENUATION IN EQUATORIAL REGION FOR

MEASAT-2 AND MEASAT-3 USING ORBITAL DIVERSITY

By

HALID BIN AGIL

Thesis Submitted to the School of Graduate Studies, Universiti Putra Malaysia,

in Fulfilment of the Requirements for the Master of Science

JULY 2012

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Abstract of thesis presented to the Senate of Universiti Putra Malaysia in fulfilment

of the requirement for the Master of Science

MITIGATION OF RAIN ATTENUATION IN EQUATORIAL REGION FOR

MEASAT-2 AND MEASAT-3 USING ORBITAL DIVERSITY

By

HALID BIN AGIL

JULY 2012

Chairman : Harlisya binti Harun, PhD

Faculty : Engineering

Rain is the main contributor towards signal attenuation for satellites operating above

3 GHz, and its effect becomes significant at 10 GHz and above. This causes satellite

signal to experience degradation, and to some extent, signal cut-off. A tropical area

such as Malaysia faces heavy rainfall throughout the year, and thus the satellite’s

signal attenuation would occur frequently. This effect is undesirable for satellite

services such as those provided by MEASAT satellites, as clients and customers

demand for uninterrupted transmissions.

Orbital diversity (OD) is seen to be a viable method to mitigate rain attenuation. It

employs multiple satellites transmitting identical signal streams toward a mutual

ground station. Although orbital diversity has been studied with great interest in

regions such as Europe, there is little information of OD research in tropical regions,

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particularly in Malaysia. Therefore, this thesis proposed an analysis of an OD

system in Malaysian climate using MEASAT satellites.

An OD simulation model has been setup using parameters from MEASAT-2,

MEASAT-3, and MEASAT Satellite Control Centre in Pulau Langkawi. It involved

a rain attenuation prediction for each satellite, based on the ITU-R recommended rain

attenuation model, signal gain prediction, and diversity gain prediction. The

simulation model has been programmed in MATLAB environment. The results are

obtained in numerical figures and graphs.

The performance of the OD system is dependent upon the operating frequency and

the satellite’s elevation angle. The simulation has shown that rain attenuation

increases exponentially with the increase of frequency. Therefore, the signal gain

decreases in an inverse exponential manner, particularly for individual signals of

MEASAT-2 and MEASAT-3. Using signal combination, an OD signal can achieve

a signal boost of up to 2.3 times the individual signal gain. With this significant

finding, the OD is proposed to mitigate rain attenuation in Malaysia.

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Abstrak tesis yang dikemukakan kepada Senat Universiti Putra Malaysia sebagai

memenuhi keperluan untuk ijazah Master Sains

PELEGAAN REDAMAN HUJAN DI DALAM KAWASAN KHATULISTIWA

UNTUK MEASAT-2 DAN MEASAT-3 MENGGUNAKAN KEPELBAGAIAN

ORBIT

Oleh

HALID BIN AGIL

JULAI 2012

Pengerusi : Harlisya binti Harun, PhD

Fakulti : Kejuruteraan

Hujan adalah penyumbang utama kepada kemerosotan isyarat untuk satelit-satelit

yang beroperasi melebihi frekuensi 3 GHz, dan kesannya menjadi ketara pada

frekuensi 10 GHz dan ke atas. Ini menyebabkan kemerosotan pada isyarat satelit,

dan pada tahap tertentu, isyarat tersebut akan terputus. Kawasan tropika seperti

Malaysia mengalami taburan hujan lebat sepanjang tahun, dan ini menyebabkan

kemerosotan pada isyarat satelit kerap berlaku. Ini memberikan kesan yang tidak

diingini ke atas perkhidmatan-perkhidmatan satelit seperti yang dibekalkan oleh

satelit-satelit MEASAT, kerana permintaan pelanggan adalah terhadap penghantaran

tanpa gangguan.

Kepelbagaian orbit (OD) adalah satu kaedah untuk melegakan redaman hujan. Ia

menggunakan pelbagai satelit yang menghantar aliran-aliran isyarat yang serupa ke

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arah satu stesen bumi bersama. Walaupun kaedah OD telah dikaji dengan minat

yang mendalam di rantauan seperti di Eropah, hanya terdapat sedikit maklumat

tentang penyelidikan OD di rantauan tropikal, terutamanya di Malaysia. Oleh sebab

itu, tesis ini mencadangkan satu analisis sebuah sistem OD dalam iklim di Malaysia

menggunakan satelit-satelit MEASAT.

Satu model simulasi OD telah disediakan menggunakan parameter-parameter

daripada MEASAT-2, MEASAT-3, dan Pusat Kawalan Satelit MEASAT di Pulau

Langkawi. Ia melibatkan ramalan redaman dari hujan untuk setiap satelit,

berdasarkan model redaman hujan yang disyorkan oleh ITU-R, ramalan gandaan

isyarat, dan ramalan gandaan kepelbagaian. Model simulasi tersebut telah diprogram

dalam persekitaran MATLAB. Keputusan simulasi telah diperolehi di dalam

berangka dan graf.

Prestasi OD bergantung kepada frekuensi operasi dan sudut dongakan. Simulasi

telah menunjukkan bahawa redaman hujan meningkat secara eksponen dengan

meningkatnya frekuensi. Oleh itu, gandaan isyarat berkurang secara eksponen

songsang terutamanya untuk isyarat individu MEASAT-2 dan MEASAT-3. Dengan

menggunakan kombinasi isyarat, suatu isyarat OD mampu mengalami peningkatan

sehingga 2.3 kali ganda berbanding gandaan isyarat individu. Dengan penemuan

penting ini, OD telah dicadangkan untuk melegakan redaman hujan di Malaysia.

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ACKNOWLEDGEMENTS

Glory be to Allah, and all praises with Him. Glory be to Allah, The Greatest.

I would like to thank my supervisor, Dr. Harlisya binti Harun and the members of the

supervisory committee: Assoc. Prof. Dr. Abd. Rahim bin Abu Talib and Assoc. Prof.

Dr-Ing. Ir. Renuganth s/o Varatharajoo for their guidance and support. I also greatly

appreciated the financial support from the university through Graduate Research

Assistant (GRA) and the Post-Graduate Scholarship Scheme. Special thanks to Mr.

Mohd Azfar bin Roslan, Mr. Saffairus bin Salih, and all staffs from the Aerospace

Engineering Department. Not forgetting Ms. Nurhaniza binti Mohamad and Ms.

Zuliana binti Ismail for their contributions. Last but not least, many thanks to my

family and my friends for their support.

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I certify that a Thesis Examination Committee has met on 20 July 2012 to conduct

the final examination of Halid bin Agil on his thesis entitled “Mitigation of Rain

Attenuation in Equatorial Region for MEASAT-2 and MEASAT-3 Using Orbital

Diversity” in accordance with the Universities and University College Act 1971 and

the Constitution of the Universiti Putra Malaysia [P.U.(A) 106] 15 March 1998. The

committee recommends that the student be awarded the Master of Science.

Members of the Examination Committee were as follows:

Mohd Ramly bin Mohd Ajir, PhD

Associate Professor Lt. Col

Faculty of Engineering

Universiti Putra Malaysia

(Chairman)

Rizal bin Zahari, PhD

Senior Lecturer

Faculty of Engineering

Universiti Putra Malaysia

(Internal Examiner)

Faizal bin Mustapha, PhD

Associate Professor

Faculty of Engineering

Universiti Putra Malaysia

(Internal Examiner)

Norbahiah Misran, PhD

Professor

Faculty of Engineering and Built Environment

Universiti Kebangsaan Malaysia

(External Examiner)

________________________________

SEOW HENG FONG, PhD

Professor and Deputy Dean

School of Graduate Studies

Universiti Putra Malaysia

Date: 22 November 2012

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This thesis was submitted to the Senate of Universiti Putra Malaysia and has been

accepted as fulfilment of the requirement for the Master of Science.

Members of the Supervisory Committee were as follows:

Harlisya binti Harun, PhD

Senior Lecturer

Faculty of Engineering

Universiti Putra Malaysia

(Chairman)

Abd. Rahim bin Abu Talib, PhD

Associate Professor

Faculty of Engineering

Universiti Putra Malaysia

(Member)

Renuganth s/o Varatharajoo, PhD

Professor Dr.-Ing. Ir.

Faculty of Engineering

Universiti Putra Malaysia

(Member)

________________________________

BUJANG BIN KIM HUAT, PhD

Professor and Dean

School of Graduate Studies

Universiti Putra Malaysia

Date:

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DECLARATION

I declare that the thesis is my original work except for quotations and citations which

have been duly acknowledged. I also declare that it has not been previously, and is

not concurrently, submitted for any other degree at Universiti Putra Malaysia or at

any other institution.

_________________________________

HALID BIN AGIL

Date: 20 July 2012

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TABLE OF CONTENTS

Page

ABSTRACT

ABSTRAK

ACKNOWLEDGEMENTS

APPROVAL

DECLARATION

LIST OF TABLES

LIST OF FIGURES

NOMENCLATURE

CHAPTER

1. INTRODUCTION

1.1. Introduction

1.2. Research Motivation

1.3. Problem Statement

1.4. Research Objectives

1.5. Research Scope

1.6. Thesis Outline

2. LITERATURE REVIEW

2.1. Introduction

2.2. Climate in Malaysian Region

2.3. Seasonal Rainfall Variation in Peninsular Malaysia

2.4. Seasonal Rainfall Variation in Sabah and Sarawak

2.5. Rain Phenomenon

2.5.1. Types of Rain Effects

2.5.2. Characteristics of Rain Systems

2.5.3. Spatial Structure of Rain

2.5.4. Classical Description of Rain Attenuation

2.6. Rain Fade Mitigation

2.7. Orbital Diversity

2.8. Developments of Research in Orbital Diversity

3. METHODOLOGY

3.1. Introduction

3.2. Methodology Overview

3.3. Identification Phase

3.3.1. Satellites Selection Process

3.3.2. Ground Station Selection Process

3.3.3. Rain Attenuation Model Selection Process

3.3.4. OD Simulation Model Configuration

3.4. Rain Attenuation Simulation Phase

3.4.1. MATLAB Simulation

3.4.2. Attenuation Exceeded for 0.01 Percent of an Average Year

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3.5. Signal Gain Simulation Phase

3.5.1. MATLAB Programming

3.5.2. Signal Gain

3.5.3. Combined Signal Gain using Maximal Ratio Combining

3.6. Diversity Gain Simulation Phase

4. RESULTS AND DISCUSSIONS

4.1. Introduction

4.2. Rain Attenuation Simulation

4.3. Signal Gain Simulation

4.4. Orbital Diversity Simulation

4.5. Parametric Study

4.5.1. Case 1 – OD Signal Strength versus Attenuation Exceeded

Probability

4.5.2. Case 2 - OD Signal Strength versus Maximum Signal

Strength During Clear Sky Conditions

5. CONCLUSIONS AND RECOMMENDATIONS FOR FUTURE

WORKS

5.1. Conclusions

5.2. Recommendations for Future Works

REFERENCES

APPENDIX A

APPENDIX B

APPENDIX C

APPENDIX D

BIODATA OF STUDENT

LIST OF PUBLICATIONS

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