Hasil Pencarian  ::  Simpan CSV :: Kembali

"The BER performance of trellis coded (TC) 8PSK with 2-branch selection (SC) and maximal ratio combining (MRC) diversities on mobile satellite communication system, which channel characterized by Nakagami fading channel is investigated. The special case of 2 branch SC and MRC diversities on independent and spatially correlated Nakagami fading are analyzed in detail, It is shown that the BER performance of TC 8PSK with diversity is better than that system without diversity, and the BER performance of system with diversity increases with increasing the Nakagami fading parameter m. Although the correlation between branches causes signal-to-noise ratio (SNR) loss relative to uncorrelated fading case for 2 branches SC and MRC diversities, the SC and MRC diversities can lead the diversity gain, that is, the improvement of BER performance of TC 8PSK with diversity is obtained over the TC 8PSK without diversity. In addition, the effect of antenna separation which causes cross correlation between the fading signals envelops on the performance of TC 8PSK with 2 branch SC and MRC diversities is also considered."

"The simplest model that is frequently used for a transmission channel is the additive white Gaussian noise (AWGN) channel model. In this model the received signal is the sum of the transmitted signal and Gaussian noise. The simple channel model has great theoretical and practical importance and is an accurate model for many communication channels, such as satellite and deep space communication channels. In many communication systems, however, the channels are subject to various impairments in addition to the additive noise. For these channels the simple model of AWGN is no longer valid and one must consider more practical and complex channel models. One of the such channel types which frequently occur in radio communication is the fading channel.In mobile radio communication system, the propagation between a base and a mobile station is not only by a direct line-of-sight path, but via many paths. These propagation paths depend largely on the. scattered reflection from many obstacles near the base and mobile stations. The received signal, at any place, consist of a large number of waves arriving from many directions. These multipath waves interfere and produce a varying field strength. The base station receiver experience similar fading as the mobile transmitter moves. The signal fluctuation rate is proportional to the vehicle speed. In many fading channels, in addition to the diffused multipath fading, there exists a dominant line-of-sight (direct) signal component. Denoting the direct component by Acos(2πfct), the received signal then can be written as r(t)= (A + a1 (t)) cos(2πfct) + aQ sin(2πfct)"

"Trellis coded modulation (TCM) formats with their excellent bandwidth and power efficiency have been widely employed in various communication systems. For mobile satellite communications, trellis coded (TC) M-ary phase shift keying (MPSK) is the primary candidate modulation technique. In the first generation mobile satellite systems, co-channel interference (CCI) does not pose a serious problem. However, second generation systems are expected to reuse frequency to increase the orbit slot spectral efficiency. Then the CCI from adjacent beams and adjacent satellite will be dominant factor determining the system performance and overall capacity. Mobile satellite communication is also suffered from strong variations of the received signal power due to the multipath fading. Typically, mobile satellite channels are modeled as Rician or Nakagami fading; that is the received signal consists of a constant line of sight signal component and a Rayleigh distributed diffuse signal component. Therefore, the performance of system on mobile satellite channels is subject to both fading and CCI.TCM and antenna diversity are two attractive methods to combat fading and CC1 effects in the mobile satellite communication systems. The research focuses on the using of TCM and antenna diversity to combat the fading and CCI effects on mobile satellite system, and analyze their performance characterized by bit error rate (BER). Because of multipath propagation , the mobile satellite communication channel is modeled as a Rician or Nakagami fading channel. This report, the BER performance of TC asymmetric MPSK with CCI and TC asymmetric MPSK with diversity on mobile satellite communication systems will be investigated and analyzed.First, the BER performance of TC- asymmetric MPSK in the presence of undesired CCI with multiple interferers and fading channel is investigated. The fading statistic for desired signal is Nakagami fading and the undesired interference signals are Rayleigh fading. We assume that all the interferers are unmodulated because most of errors are produced by Rayleigh fading itself rather than the modulating sequence. This model assumes that all interfering signals have aligned symbol timing and no cross channel interference symbol interfering (ISi) effects. The desired signal is assumed to have Nakagami distribution implying that a dominant multipath exists in transmission. The desired and the interfering carrier have no phase coherence. We derive the BER performance of TC asymmetric MPSK in the presence CCI and fading channels by using the first error event method. It is shown that the BER performance of TC asymmetric MPSK in the presence of CCI is better than that of system with asymmetric MPSK. The BER performance of TC asymmetric MPSK is improved as increasing either the Nakagami fading parameter or the value of signal-to-interference ratio (SIR). As the Nakagami fading parameter is increased the phase signal of MPSK is also increased.Second, the BER performance of TC MPSK with 2 branch selection combining (SC) and maximal ratio combining (MRC) diversities on independent and spatially correlated Nakagami fading channel are investigated. The upper bound bounds using the transfer function bounding technique are derived and several numerical results are shown. Is shown that the BER performance of TC 8PSK with MRC diversity is better than that of system with SC diversity. Although the correlation between branches causes the signal-to-noise ratio (SNR) loss (relative to independent fading case) for SC and MRC diversities, the diversity can lead to achieve the diversity gain compared to the system without diversity.Third, the BER performance of TC 8PSK in the presence of undesired CCI with multiple interferers and fading channel is investigated by using computer simulation. The fading statistic for desired signal is Nakagami fading and the undesired interference signals are characterized by Rayleigh fading. The I3ER performance of TC 8PSK in the presence CC1 and fading channels is simulated by using the first error event method. It is shown from the result that the simulation result of the performance of TC 8PSK in the presence CCI and fading channels is closed to the analytical result."

"ABSTRAKAnalisis Situasi: Jakarta selain sebagai pusat pemerintahan juga merupakanpusat hiburan yang memiliki berbagai daya tarik wisatasalah satunya pariwisata makanan atau gastronomi dengan menawarkan hampir 4.000 gerai makanan. Perkembanganteknologi dan informasi yang cepat juga berpengaruh pada bidang kuliner yang mendorong perilaku generasi mudalebih suka makan di luar rumah dengan mencari referensi gerai makan di internet. Namun, masyarakat membutuhkanlebih dari sekedar referensi. Hal yang terjadi dengan banyaknya referensi gerai makan atau makanan menimbulkan efek konsumtif bagi masyarakat, karena kebanyakan hanya menyajikan makanan tanpa disertai sisiedukasinya. Media baru jurnalisme makanan ini dengan lingkup Jakarta dapat menjadi upaya dalam memberikan informasi akurat dan komprehensif tentang makanan danmemberikan manfaat positif bagi masyarakat. Manfaat dan Tujuan: Pengembangan Prototipe: Memberikan informasi komprehensif dan aktual mengenaimakanan di Jakarta kepada masyarakat. Tujuannya adalahmenjadi pionir media jurnalisme makanan dengan formatmobile-app yang mudah diakses, dinamis, interaktif,menarik serta menawarkan informasi yang komprehensif. Prototipe yang Dikembangkan: Jakartagastro adalah media jurnalisme makanan berbasis mobile-application yang memiliki wilayah cakupan Jakarta. Media ini memiliki berbagai konten yang dibutuhkan khalayak diantaranya liputan terkini, informasi umum gerai makanan, ulasan, resep, nutrisi, dan latar belakang sejarah suatu makanan. Evaluasi: Pre-tes dilakukan sebelum situs diluncurkan denganmenyebarkan kuesioner langsung kepada khalayak. Evaluasi khalayak hampir sama dengan pre-test dilakukan untuk melihat kepuasan khalayak terhadap situs. Evaluasi input, output, dan outcome akan dilakukan dengan analisislaporan divisi serta survei khalayak setiap empat bulan. Anggaran: Anggaran Pembuatan Prototipe Rp 745.000. Investasi Awal Rp 79.067.000Total Pengeluaran Bulanan Rp 139.000.000Total Pengeluaran 1 Tahun Rp 1.602.000.000Perkiraan Pendapatan Tahun Pertama Rp 325.596.000. Perkiraan Pendapatan Tahun Kedua Rp 1.883.400.000.

---

ABSTRACTSituation Analysis: Jakarta as the central government, also holds a role as thecenter of entertaiment with various tourism attractions. Oneof tourism attractions is its gastronomy tourism, providingalmost 4000 outlets. Rapid development of technology andinformation also give massive effect to gastronomy industry. It drives people to go eating out more often andusually using the internet as their reference. But, peopleneed more than reference. Sadly, people become moreconsumptive, because the references only cover about theproducts and overlook its educative role. New food journalism can be a platform for giving accurate and comprehensive information about food and positive impactto society. Benefits and Goals of Developing Prototype: To give comprehensive and actual information related tofood in Jakarta. The objective is to be pioneer as a dynamicand interactive food journalism media.Developing Prototype: Jakarta gastro is mobile app basis food journalism mediawith coverage in entire Jakarta. This media provides actualinformation, recipe, nutrition, related to food. Evaluation: The pre test will be conducted before the site is launched bydistributing questionnaires directly to the audience.Evaluation of the audience is almost the same as the pre test. It will be conducted to see the satisfaction of the audiencefor the site. Evaluation of inputs, outputs, and outcomes willbe conducted by analyzing reports of division and surveysevery four months. Budgeting: Protoype development budget Rp 745.000Initial Investments Rp 79.067.000. Total monthly expenses Rp 139.000.000. Expenses in a year Rp 1.602.000.000Predicted income first year Rp 325.596.000. Predicted income second year Rp 1.883.400.000 "

"Performansi mobile WiMAX dipengaruhi oleh beberapa faktor, diantaranya adalah kondisi propagasi radio, posisi dan mobilitas pengguna dan skema error control coding (ECC) yang digunakan. Analisis terhadap faktor-faktor tersebut tentunya akan sangat bermanfaat dalam proses perencanaan dan penerapan teknologi WiMAX mobile. Dalam skripsi ini akan dibahas beberapa faktor yang mempengaruhi performansi WiMAX mobile menggunakan teknik LDPC (low-density parity check code) sebagai error control coding-nya. Indikator performansi yang digunakan dalam simulasi adalah bit error rate (BER) dan frame error rate (FER). Beberapa parameter yang diujicoba yaitu, teknik modulasi, kondisi kanal transmisi, rate informasi, jumlah bit kode, jumlah iterasi maksimum LDPC code, algoritma demodulator dan decoder, serta interleaver. Teknik modulasi yang digunakan adalah QPSK, 16-QAM, dan 64-QAM. Kondisi kanal transmisinya adalah AWGN dan Rayleigh fading. Coderate-nya yaitu ½, 2/3, ¾, dan 5/6. Algoritma demodulator yaitu maximum a posteriori probability pada domain log (log-MAP). Algoritma decoding yang digunakan yaitu sum-product decoding dan min-sum decoding. Terakhir, penerapan bit interleaver coded modulation (BICM).Hasil simulasi menunjukkan bahwa beberapa faktor tersebut mempengaruhi performa BER dan FER sistem WiMAX mobile.

---

Mobile WiMAX performance is affected by several factors, such as air interface condition, user mobility and position, and error control coding scheme. Analysis of these factor are very useful for implementation of these technology. This paper will study several factors that affect the performance of mobile WiMAX based on low density parity check code as the error control coding. This simulation uses bit error rate (BER) and frame error rate (FER) as the indicator performance. Several paramaters that being tested are modulation technique, air interface condition, information rate, number of code bits, number of maximum iteration of LDPC code, decoding algorithm, and bit interleaver. The modulation technique are QPSK, 16-QAM, and 64-QAM. Air interface condition are AWGN and Rayleigh fading. The information rate are ½, 2/3, ¾, and 5/6. The decoding algorithm are log-MAP, sum-product decoding, and minsum decoding. Last, the use of bit interleaver coded modulation.Simulation results show that these factor affected the performance of mobile WiMAX system, especially the modulation technique, air interface condition, information rate, maximum number of iteration, and number of code bits."

"Teknologi terus berkembang, teknologi-teknologi baru yang lebih canggih dari teknologi sebelumnya banyak bermunculan. Namun, banyak kasus di mana pengguna tidak mau beralih dari teknologi lama ke teknologi baru tersebut. Permasalahan mengenai keengganan pengguna untuk beralih ini dialami oleh PT Cookpad Digital Indonesia. Pengguna situs web mobile tidak banyak yang mau beralih ke aplikasi mobile. Penelitian ini bertujuan untuk mengidentifikasi faktor-faktor pendorong dan penghambat yang memengaruhi pengguna untuk beralih dari situs web mobile ke aplikasi mobile Cookpad. Pendekatan teoretis yang dipakai adalah two factor theory, di mana dihipotesiskan ada faktor-faktor pendorong dan faktor-faktor penghambat yang berpengaruh dan bekerja secara independen. Penelitian dilakukan dengan mengambil data kuantitatif melalui survei kuesioner yang disebarkan secara daring kepada pengguna situs web Cookpad di Indonesia. Sebanyak 406 data responden terkumpul, dengan 331 data responden yang valid. Hasil survei dianalisis menggunakan metode Structural Equation Modiling dengan bantuan IBM SPSS AMOS. Hasil penelitian menunjukkan bahwa functional deprivation, interactivity, dan social identification berpengaruh sebagai faktor pendorong dan inertia terbukti sebagai faktor penghambat bagi keputusan pengguna situs web mobile untuk beralih memakai aplikasi mobile.

---

With the advancement in technology world, a lot of newer and better technology are introduced. However, there are many cases where users don 39 t want to adopt the new and better technology, instead they keep using the old technology. This problem of users 39 inertia, not wanting to switch to new technology, is now being faced by PT Cookpad Digital Indonesia Cookpad Indonesia . Only few Cookpad mobile web users that want to switch to use Cookpad mobile application.

The purpose of this research is to identify the factors, enablers and inhibitors, that influence Cookpad mobile website users to switch to use Cookpad mobile application. Two factor theory, which states that there are enablers and inhibitors that work independently to influence behavior, is used as theoretical framework for this research.

Quantitative data using Likert scale was collected through questionnaire survey targeting Cookpad Indonesia users. 406 questionnaires were collected, with 331 of them are valid. IBM SPSS AMOS was used to analyze survey result using Structural Equation Modeling method.

Functional deprivation, interactivity, and social identification were identified as enablers, while inertia was identified as inhibitors for users 39 intention to switch from mobile website to mobile application."