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Abstrak :
Background: Depression is a significant geriatric problem. It will be a major health problem in developing nations by the year 2020. Signs and symptoms of depression among elderly people are usually so unspecific that they are often considered as a part of getting old. No wonder so many elderly depression cases remain uncured. When depression is under-diagnosed, the various problems accompanied with it will make the bio-psychosocial condition of the patient worsen. There is no primary data on the prevalence of depression in the Indonesian elderly population, especially in Eastern Indonesian conflict areas. Objective: The objective was to determine the prevalence and the severity of depression, as well as cognitive function in elderly subjects living in the conflict area in Buru Island, Maluku. Design: This study was designed as a survey, conducted in the Northeast Buru Region, Maluku, from March to May 2003. Questionnaires on the validated Geriatric Depression Scale and Mini Mental State Evaluation were performed by trained native speaker paramedics for the identification of depression, the severity of depression, and cognitive function. The 401 elderly people that participated in this survey ranged in age from 60 to 120 years. As many as 215 (53.6%) were women, and 223 (55.6%) were uneducated. Results: The prevalence of depression was 52.4%. A hundred and eighty seven subjects (94 females and 93 males) aged 60-120 years were in the mild depression category, and 23 subjects (14 females and 9 males) aged 60-85 years were severely depressed. While 82.6% elderly in severe depression category had an MMSE Score of less than 24 (dementia), 74.7% had mild depression, and only 57.1% of the elderly had no depression and received MMSE score less than 24. The majority of complaints among depression subjects were that they were bothered by thoughts they cannot get out of their head, they frequently worry about the future, they often became restless and fidgety, got bored, felt helpless, downhearted and blue, felt like crying, and that their life was empty. Seventy eight percents mild depressive elderly still enjoy getting up in the morning and 68% were hopeful about the future, which was on the contrary to the subjects with severe depression, where only 35% had these two positive outlooks. Conclusions: The prevalence of depression in Buru Island community was high, even though most of them were in the mild depression category. The worse the depression, the higher the percentage of cognitive impairment. There was still enough willingness to get better among subjects with mild depression. We need to think about the possibility of Post Traumatic Stress Disorder in the elderly population of this conflict area. Suggestions: Medical practitioners in conflict areas need to increase their awareness of depression and cognitive impairment among elderly people. Geriatrician and psychogeriatric experts are needed to ensure that the problem of depression in the elderly does not worsen in conflict areas. Further studies are needed to detect Post Traumatic Stress Disorder.

Abstrak :
Penelitian-penelitian tentang kapasitas reverse link sistem wireless code division multiple access (CDMA) kurang menunjukkan kapasitas yang sebenamya karena hanya memperhitungkan pengaruh ketidak-sempurnaan pengendalian daya oleh shadowing hanya pada homecell (sel sendiri) saja atau pada sel-sel tetangga saja. Pada kenyataannya, shadowing pasti terjadi antara base station (BS) and mobile station (MS). Oleh karena itu tesis ini menganalisa secara matematis kapasitas reverse link sebuah sistem wireless CDMA yang mendukung layanan suara (kelas-1) dan data (kelas-2) secara terpadu dengan memperhatikan pengaruh pengendalian daya karena shadowing pada sistem selular dua-tier. Selain itu, pengaruh aktifitas suara dan variable spreading gain dari user kelas-2 terhadap kapasitas user kelas-1 dan pengaruh sektorisasi terhadap kapasitas kedua layanan tersebut juga dianalisa. Dari pengamatan dan analisa yang telah dilakukan menunjukkan bahwa faktor yang berpengaruh terhadap kapasitas sistem wireless CDMA diantaranya faktor aktifitas user, sektorisasi dan shadowing. Dengan pengendalian daya reverse link, apabila downlink shadowing lebih besar dari pada uplink shadowing, user akan mengirimkan daya lebih besar dari yang dikehendaki BS sehingga menimbulkan interferensi sesama user di BS. Interferensi juga dapat berasal dari user lain yang memiliki bit rate lebih besar (spreading gain kecii) karena bit rate yang besar rnemerlukan daya yang besar. Penurunan kapasitas karena shadowing sampai dengan 4 dB dapat diatasi dengan sektorisasi sel.

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The existing researches on the reverse link capacity of a wireless code division multiple access (CDMA) system did not exactly represent its reverse link capacity. These were because they considered that the effect of shadowing was experienced by a home cell or other cells only. In fact, the shadowing absolutely exists between base station (BS) and mobile station (MS). So, this thesis mathematically analyzes the reverse link capacity of a CDMA system which supports integrated services (voice - class-1 and data -- class-2) that considers power control due to shadowing in a two tiers of a cellular system. In addition, the effect of variable spreading gain of class-2 users on class-1 users' capacity and by dividing cells into sectors are also observed. Observations and analyses show that some factors which determine the capacity of a wireless CDMA system such as user activity factor, sectorization and shadowing. In a reverse link power control, if downlink shadowing is higher than uplink shadowing, user will transmit power more than its actually required by the BS, so this power will cause interference to others. On the other hand, interference also comes from users who have a signal with a higher bit rate (has a small spreading gain) because a higher bit rate also requires a higher power. Capacity decaying due to shadowing up to 4 dB can be solved by using a cell sectorization.

Abstrak :
Komunikasi tanpa kabel pada masa depan akan menuju pada penyatuan beberapa jenis trafik yang berbeda seperti suara, data, gambar dan kompresi video. Untuk mendukung pelayanan ini, jaringan yang tersedia harus memiliki kemampuan dalam meyediakan berbagai macam kebutuhan termasuk rate dan QoS yang berbeda. Berbagai macam cara untuk mengontrol QoS pada sistem CDMA antara lain dengan menentukan nilai daya yang dikirim, processing gain dan jumlah kode yang digunakan. Penggunaan processing gain dan daya yang dikirim memberikan pengaruh yang besar pada unjuk kerja sistem CDMA Optimasi processing gain akan meningkatkan rentang kapasitas dan QoS, termasuk error rate yang rendah, throughput yang besar dan delay yang kecil. Dalam sistem kelas jamak menggunakan kode jamak, user data akan mendapatkan rate yang sama seperti user suara, sehingga level daya yang digunakan kedua jenis user tersebut sama. Hal ini akan mengoptimalkan unjuk kerja sistem. Tesis ini menganalisa perumusan matematis dari kapasitas multiclass CDMA dengan multicode. Dengan penggunaan multicode diharapkan unjuk kerja sistem akan meningkat.

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Future services for wireless communication will lead to integrity of several different types of traffics such as voice, data, image and video compressing. To support these services, the available network must have the ability in providing various needs including different rate and QoS. Some ways to control the QoS in the CDMA system are choosing certain value of transmitted power, processing gain and number of codes. The use of processing gain and transmitted power give a great influence to the performance of CDMA system. Optimizing the processing gain will increase the range of capacity and also the QoS, including low error rate, large throughput and small delay. In a multiclass system using multicode, data users will have the same rate as voice users leading to the same level power used by both users. This will optimize the system. This thesis will further discuss mathematics derivation of cellular CDMA capacity for multiclass using multicode scheme. Using multicode, system performance will hopefully increase.

Abstrak :
Teknologi komunikasi tanpa kabel masa depan dituntut untuk mampu melayani aplikasi multimedia termasuk informasi suara dan data berkecepatan tinggi. CDMA adalah salah satu teknologi yang dapat diaplikasikan dan telah dibuktikan sebagai teknik akses jamak yang mampu untuk menyediakan berbagai macam kebutuhan layanan tersebut. Pada tesis ini akan dibahas analisa throughput dan kapasitas sistem multi sel dan multi kelas CDMA. Sistem multi sel dianalisa sampai dengan dua tier sedangkan sistem multi kelas dibagi menjadi 2 trafik yaitu kelas-1 untuk layanan suara dan kelas-2 untuk layanan data. Kinerja sistem dihasilkan dari perhitungan throughput untuk layanan kelas-2 dan perhitungan BER untuk layanan kelas-1. Analisa kapasitas dan throughput didasarkan pada pengaruh dari variasi kecepatan chip, kecepatan bit dan faktor aktivitas. Hasil analisa menunjukkan, dengan kecepatan chip yang lebih besar dapat memperbaiki BER yang dibutuhkan oleh tiap layanan informasi serta dapat meningkatkan kapasitas dan throughput sistem pada saat kondisi trafik padat. Sebaliknya, kecepatan bit yang lebih besar akan menurunkan kapasitas dan throughput total sistem. Semakin besar faktor aktivitas akan menaikkan throughput namun menurunkan kapasitas total sistem. Pengaruh interferensi pada sistem multi sel dan multi kelas dapat menurunkan throughput dan kapasitas total dari trafik informasi yang ditawarkan.

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The future technology of wireless technology of wireless communication system must be able to serve a multimedia application, included voice and high speed data information. DS-CDMA is one of communication technology which can used and have been proved as technique of multiple access that capable to provide this service requirement. In this thesis, analysis of throughput and capacity are proposed for multi cell and multi class CDMA system. System of multi cell analyzed until two tier and system of multi class divided two classes of traffic that are class-1 far voice and class-2 for data services. Performance measurement is obtained in respect of throughput for class-2 traffic and BER for class-1 traffic . Analysis of throughput and capacity according to the effect of variable quality of services, chip rate, bit rate and activity factor. The result show that with larger chip rate can maintain the required BER of each information and achieve the capacity and throughput in high traffic condition. Otherwise, with larger bit rate will decrease total throughput and capacity. With larger activity factor will decrease total capacity but can increase throughput of system. The effect of interference in multi cell and multi class system can decrease throughput and total capacity of offered information traffics.

Abstrak :
Dalam tesis ini diajukan sistem gabungan multicarrier code-division multiple-access (Multicarrier CDMA) dengan skema Pure Aloha (P-Aloha) dan Slotted Aloha (S-Aloha), yang disebut multicarrier CDMA P-Aloha dan multicarrier CDMA S-Aloha. Analisa terhadap kedua sistem dilakukan terhadap salah satu parameter kinerja sistem yaitu throughput. Dalam sistem multicarrier CDMA P-Aloha dan multicarrier CDMA S-Aloha, data mula-mula dikonversi dari serial menjadi paralel. Data tersebut kemudian dimodulasi dengan direct sequence spread-spectrum (DS-SS) menggunakan kode penyebar yang spesifik pada setiap user, dan semua sinyal DS tersebut ditransmisikan secara paralel pada subcarrier yang berbeda-beda. Setelah dikodekan, data dikirim secara acak untuk sistem multicarrier CDMA P-Aloha, sedangkan pada multicarrier CDMA S-Aloha data dikirim pada permulaan time-slot sesuai mekanisme sistem S-Aloha. Hasil penelitian menunjukkan bahwa kedua sistem memiliki throughput yang tinggi untuk transmisi sinyal dengan laju tinggi, dan multicarrier CDMA S-Aloha memiliki throughput yang lebih tinggi daripada multicarrier CDMA P-Aloha. Hasil penelitian juga menunjukkan bahwa throughput kedua sistem semakin tinggi dengan meningkatnya jumlah subcarrier dan panjang kode single-carrier yang digunakan, sementara peningkatan panjang subpaket menurunkan throughput kedua sistem. Multicarrier CDMA Aloha memiliki throughput yang lebih baik dari CDMA Aloha.

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This thesis proposes integrated systems consisting of multicarrier code-division multiple-access (Multicarrier CDMA) with Pure Aloha (P-Aloha) and Slotted Aloha (S-Aloha) schemes, named multicarrier CDMA P-Aloha and multicarrier CDMA S-Aloha, respectively. The performance analysis of both systems is stated as throughput, Multicarrier CDMA Aloha is proposed to improve the performance of CDMA Aloha. In multicarrier CDMA P-Aloha and multicarrier COMA S-Aloha the initial data is serial-to-parallel converted to a number of lower rate data streams. Each stream which consists of a part of the initial data called sub-packet will be then direct sequence spread-spectrum modulated using specific spreading code for each user, and all the DS-SS signals are transmitted in parallel on different subcarriers. The coded data is sent randomly in multicarrier CDMA P-Aloha system, whereas in multicarrier CDMA S-Aloha, the data is sent at the beginning of the time-slot according to the mechanism of S-Aloha system. Results show that both systems have high throughput for high bit rate signal transmission, and multicarrier CDMA S-Aloha outperforms multicarrier CDMA P-Aloha. It is also shown that the throughput of both systems improves as the number of subcarriers and the length of single-carrier code increase, while the increase of subpacket length degrades the throughput of both systems. Multicarrier CDMA Aloha has better performance compared to CDMA Aloha.

Abstrak :
Pada Tesis ini akan dibahas unjuk kerja modulasi kode trellis 4 state 8 phase-shift keying (TC 8PSK) dengan teknik diversitas rang Maximal Ratio Combining (MRC) pada kanal fading Nakagami serta adanya co-channel interference, (CCI) jamak yang diasumsikan besar dayanya sama. Analisa matematis dilakukan untuk mendapatkan persamaan bit error rate (BER) dari sistem model yang digunakan. Beberapa hasil perhitungan BER ditampilkan. Dari hasil terlihat bahwa unjuk kerja BER TC SPSK dengan teknik diversitas MRC diperburuk dengan kehadiran CCI, walaupun peningkatan jumlah cabang diversitas akan memperbaiki unjuk kerjanya.

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This thesis presents the performances of trellis coded moddrlation 4 state 8 phase shift keying (I'C 8PSK) with space diversity maximal ratio combing (MRC) in a Nakagami fading channel in the presence of multiple equal power cochannel interferers. With mathematics analysis we have bit error rate (BER) from model system in used. Some of the result from BER calculation is shown. The result shown that the performances of BER TC 8PSK with MRC diversity more worst in the presence of cochannel interferers although more branch in diversity can repair the performances.

Abstrak :
Penelitian ini bertujuan untuk mengevaluasi dan menganalisa kinerja integrasi metode akses inhibit and random multiple access (IRMA) dengan code division multiple access (CDMA) dan multi code CDMA yang disebut sebagai CDMA IRMA dan MC-CDMA IRMA, untuk diapalikasikan pada integrasi suara dan data dalam sistem komunikasi wireless. Kinerja yang akan dianalisa dinyatakan sebagai throughput dan outage probability. Pada CDMA IRMA, analisa kinerja dilakukan pada dua kondisi, yaitu : 1). Kanal dengan trafik data dan 2). Kanal dengan multi trafik. Kondisi trafik dimodelkan dan dianalisa dengan menggunakan "Markovian Process". Pada MC-CDMA IRMA, analisa akan dilakukan terhadap user data yang dibagi atas dua kelas dengan dibedakan atas nilai kecepatan transmisi yang diperlukan, yaitu data user kelas I denagan bit rate yang tinggi, dan data user kelas II dengan bit rate yang rendah. Hasil penelitian memperlihatkan bahwa throughput CDMA IRMA semakin tinggi apabila pentransmisian simultan data, kd ; pentransmisian simultan suara, kv ; processing gain data, nd dan processing gain suara, nv semakin besar, sedangkan outage probability akan semakin baik dengan p yang semakin besar. Throughput MC-CDMA IRMA semakin tinggi apabila jumlah kode, F dan processing gain, N semakin besar, sedangkan outage probability semakin baik dengan p yang semakin besar.

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In this paper the performance of integration between inhibit and random multiple access (IRMA) with code division multiple access (CDMA) and multi code CDMA called as CDMA IRMA and MC-CDMA IRMA will be evaluated and analyzed. The performances are characterized as throughput and outage probability. CDMA IRMA and MC-CDMA IRMA use on voice and data integration, for CDMA IRMA, performance analysis is done for two conditions, namely : 1). Channel containing data traffic and 2). Channel containing multi traffic. Both channel conditions are modeled and analyzed using "Markovian Process". For MC-CDMA IRMA, the user data being analyzed is divided into two classes based on transmission rate needed, users of class I require transmission at a higher bit rate than those of class II. The research results that the throughput of CDMA IRMA increase as the value of number of simultaneous transmission data, kd; number of simultaneous transmission voice, kv ; data processing gain, nd and voice processing gain, nv, increase, while outage probability improves as the value of p increases. The throughput of MC-CDMA IRMA increases as the values of number of code, F and number of processing gain, N increases while the outage probability improves as the value of p increases.

Abstrak :
Penelitian ini membahas analisa kapasitas reverse link sistem makro/mikroselular CDMA dengan menggunakan pengaturan perbandingan daya yang diterima pada base station (BS) makrosel/mikrosel dan pemiringan sudut antena mikrosel (tilted antenna). Pada sistem model yang diusulkan ditempatkan masing-masing sebuah mikrosel pada setiap makrosel. Pada sistem tersebut makrosel dan mikrosel bekerja pada band frekuensi yang sama, tetapi level dayanya diatur berbeda untuk mendapatkan perbandingan yang optimum. Penggunaan band frekuensi yang sama oleh makrosel dan mikrosel menyebabkan terjadinya interferensi sehingga mempengaruhi kapasitas sistem. Pada sistem makro/mikroselular CDMA terdapat empat jenis interferensi, yaitu interferensi dari makrosel-mikrosel, interferensi dari mikrosel-makrosel, interferensi dari makroselmakrosel dan interferensi dari mikrosel-mikrosel. Dari hasil yang diperoleh penggunaan teknik pengaturan perbandingan daya (power ratio control) yang optimum menghasilkan kapasitas user makrosel lebih besar dibandingkan dengan teknik penyamaan daya yang diterima sama (equal power received) pada BS makrosel/mikrosel. Penggunaan pemiringan sudut antena mikrosel pada teknik pengaturan perbandingan daya dapat meningkatkan kapasitas sistem.

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The reverse link capacity of macro/microcellular code-division multiple-access (CDMA) is obtained analytically in this research, which is using power ratio control technique and tilted microcell antenna. In the proposed system model, we placed a microcell at every macrocell. The macrocell and microcell are operating in the same frequency band. The different power received of both macrocell and microcell base stations are controlled to obtain the optimum power ratio. The use of the same frequency band of both macrocell and microcell causing the interference which is decreasing capacity of the system. In macro/microcellular CDMA systems, there exist four kinds of other cell interference. For example, the macrocell-tomicrocell interference, the microcell-to-macrocell interference, the macrocell-tomacrocell interference and the microcell-to-microcell interference. It is shown that the system capacity with power ratio control increase remarkably than the system with equal power receive of BS macrocell/microcell. Also, the optimum tilt angle of microcell antenna adds more capacity.