Hasil Pencarian  ::  Simpan CSV :: Kembali

"The book briefs you on energy propagation around and into the body and how to estimate performance of on-body wireless links, and then dives into the nuts-and-bolts of designing antenna systems that deliver the goods. It covers on-body communication channels at microwave frequency bands and at low frequency bands, as well as ultra wideband systems for WPANs and WBANs. You get details on body-centric UWB antennas and channels, as well as advances in wearable mobile, EBG, and ?smart fabric? antennas for cellular and WLAN communications. Chapters on telemedicine applications, such as remote diagnoses, and implantable medical devices cover crucial propagation issues and other obstacles that need to be addressed. Rounding out the coverage is a section on antenna design for body-sensor networks and their emerging military and space applications. Packed with hands-on guidance from noted experts, this volume will be indispensable for your efforts in designing and improving body-centric communication systems. (Publisher)"

"This book describes the design and implementation of an electronic subsystem called the frequency synthesizer, which is a very important building block for any wireless transceiver. The discussion includes several new techniques for the design of such a subsystem which include the usage modes of the wireless device, including its support for several leading-edge wireless standards. "

"Teknologi komunikasi berkembang dengan pesat. Dimulai dari teknologi 1G,2G,3G dan selanjutnya sekarang 4G. Bertujuan memenuhi tuntutan era digital dewasa ini yang terus berkembang, yakni kebutuhan akan informasi sebanyak-banyaknya dengan kemampuan mobile broadband akses yang handal. Indonesia khususnya DKI Jakarta yang baru saja memulai mengimplementasikan teknologi 3G, harus segara bersiap akan kemungkinan dimplementasikan teknologi 4G dalam waktu dekat ini. Salah satu keunggulan teknologi 4G diantaranya mendukung jaringan Ad hoc networks dan multi-hop networks. Hal ini menjadikan 4G sebagai teknologi seluler memiliki keunikan tersendiri. Dalam tulisan ini perhitungan ekonomis implementasi 4G di DKI Jakarta menggunakan formula seperti Net Present Value (NPV) yaitu kriteria investasi yang banyak digunakan dalam mengukur apakah suatu proyek feasible atau tidak, Pay Back Period (PBP), Break Even Point (BEP)dan Internal Rate of Ratio (IRR). Penganalisaan dilakukakan dengan kondisi sosial-geografis, regulasi serta kondisi jakarta seperti sekarang ini. Dengan bahan kajian adalah luas Jakarta 740,28 km2 serta pertumbuhan pelanggan seluler di Jakarta yang diprediksi dalam 5 tahun kedepan diperkirakan sebesar 28.456.500 juta orang. Dimana terdapat masa pre-implementasi 4G di DKI Jakarta tahun (2008 ? 2011) serta dikomersialisasikan pada tahun (2011-2016). Perhitungan ekonomi digunakan untuk menentukan skenario yang tepat dimplementasikan. Dengan hasil bahwa skenario I smooth development NPVnya 18.812.165.000, skenario II economic stagnation NPVnya -14.550.902.000, skenario III constant change -24.561.622.000. Adanya beberapa skenario tersebut karena implementasi baru akan terjadi dimasa yang akan datang. Dimana data yang diolah adalah data pertumbuhan pelanggan seluler yang diasumsikan pada tahun 2011. Kesimpulan dari analisa ini diperoleh skenario smooth development yang tepat untuk diimplementasikan. Dimana revenue diperoleh pada tahun III sebesar (25.748.800.000), karena masa BEP tejadi pada tahun tersebut dari kurun waktu lima tahun (2011- 2016). Maka dari hasil analisa ini implementasi 4G di DKI Jakarta layak dilakukan pada tahun 2011 dengan menggunakan skenario smooth development.

---

One of the most cutting edge and unique features of 4G is that it supports Ad hoc and multi-hop networks. This paper will be using common formulas such as, Net Present Value (NPV), Pay Back Period (PBP), Bear Even Point (BEP) and Internal Rate of ratio (IRR) to calculate the feasibility of 4G ?s implementation in DKI Jakarta. The study and analysis are going to be done by looking at the present social and geographical conditions ? with Jakarta?s current area of 740,28 km2 in size and the predicted cellular phone users of 28.456.500 million users within the next 5 years - and the city?s regulations to calculate the mentioned formulas. This will information will take into account that it will be included in pre-implementation time (2008 ? 2011) and full implementation (2011-2016) of 4G in DKI Jakarta. The calculations are going to be used to choose the most precise scenario of implementing 4G technology. The result of Scenario I with smooth development of NPV of 18.812.165.000, Scenario II with economical stagnation of NPV of - 14.550.902.000, Scenario III constant change -24.561.622.000. Those scenarios are the result of new implementations that will happen in the future by using the assumption growth of cellular phone users in 2011. This analysis concludes that smooth development is the best scenario for implementing 4G in DKI Jakarta with revenue on the 3rd year (out of 5 years, 2011- 2016) of 25.748.800.000 due to the BEP that will going to take place on that year. Communication technology is an ever growing technology. Communication generation technologies have grown from its first generation (1G) to 2G all the way to 3G, and now we are starting to develop the fourth generation (4G) with an aim to fulfill the user?s needs using a reliable mobile broadband access. Indonesia, specifically DKI Jakarta that has just started implementing the 3rd Generation (3G) needs to prepare with the possibility of 4G implementation sooner than they expected."

"This exceptional book introduces the reader to the principles, theory and applications of physical layer wireless/mobile communications. In the area of wireless, the antennas, propagation and the radio channel used are interrelated; this book offers an explanation of that relationship which is fundamental to the development of systems with high spectral efficiency.The book emphasises the basic principles needed to establish an understanding of this technology. However, the tools required - such as the mathematics and statistics - are treated in the manner of a practical handbook, avoiding detailed derivations. The reader will develop a clear insight into the physics and effects of multipath and the use of multipath channels for communications. Propagation modelling, simulation and measurement, scattering, antenna principles, array antennas, adaptive antennas and smart antennas are also covered."

"Tantangan terbesar pengembangan layanan komunikasi wireless adalah frequency-bandwidth yang terbatas dan mahal. Karena itu dibutuhkan tidak hanya sistem berkecepatan tinggi saja tetapi juga sistem yang mampu menggunakan bandwidth secara efisien. Walaupun sulit membangun sistem berkecepatan tinggi dengan error-rate rendah, namun pada tulisan ini diperkenalkan sebuah sistem closed-loop MIMO (Multiple-Input Multiple-Output) menggunakan detektor ML (Maximum Likelihood) sederhana untuk mengoptimalkan kapasitas dan meningkatkan performansi sistem. Pemakaian MIMO menjadi spesial karena kemampuannya dalam meningkatkan kapasitas dan performansi tanpa menambah frequency-spectral. Skenario besar konsep ini didapat dari keuntungan pemakaian matriks transformasi yang mampu mengalokasikan daya sinyal-sinyal transmisi sesuai dengan kondisi kanal. Selain itu, perkalian matriks ini dapat membentuk kanal-kanal singular yang paralel. Sehingga dengan zero inter-channels correlation, maka detektor ML dapat dirancang guna meningkatkan performansi. Pada akhirnya, simulasi komputer memberikan validasi bahwa pada SNR (Signal-to-Noise Ratio) 0 dB dapat dicapai kapasitas optimal sampai 1 bps/Hz dan SER sampai dengan 0,2 lebih baik dari sistem opened-loop MIMO.

---

In order to support providing broadband wireless communication services against limited and expensive frequency bandwidth, we have to develop a bandwidth efficient system. Therefore, in this paper we propose a closed-loop MIMO (Multiple-Input-Multiple-Output) system using ML (Maximum Likelihood) detector to optimize capacity and to increase system performance. What is especially exciting about the benefits offered by MIMO is that a high capacity and performance can be attained without additional frequency-spectral resource.

The grand scenario of this concept is the attained advantages of transformation matrices having capability to allocate transmitted signals power suit to the channel. Furthermore, product of these matrices forms parallel singular channels. Due to zero inter-channels correlation, thus we can design ML detector to increase the system performance. Finally, computer simulations validates that at 0 dB SNR our system can reach optimal capacity up to 1 bps/Hz and SER up to 0.2 higher than opened-loop MIMO."