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"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 For these channels the simple model of AWGN is no longer valid and one must consider more practical and complex channel models.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."

"A thoroughly up-to-date revision of this successful book, based on the series of IEE Vacation Schools. The text aims to give the professional engineer or graduate student a fully comprehensive yet practical understanding of the principles and technological issues of this major subject. As with all Vacation School based material, there is a strong tutorial element and real-world orientation."

"Penelitian ini menghasilkan suatu rangkaian Modulator dan Demodulator Offset Quadrature Phase Shift Keyed (OQPSK) dengan menggunakan rangkaian lojik untuk memperoleh suatu rangkaian modulator maupun demodulator yang kompak, mempunyai keandatan yang lebih tinggi, dan dapat dibuat diatom bentuk CMOS ICS sehingga membutuhkan daya listrik yang keci1. Disamping itu pula dengan menggunakan rangkaian lojik dapat dikuatkan dengan menggunakan rangkaian penguat klas C yang mempunyai efisiensi lebih tinggi dibandingkan dengan penguat Linear yang umum digunakan pada modulator konvensional. Dari penelitian ini diperoleh suatu rangkaian Modulator yang terdiri dari 3 buah D flip-flop 7474 untuh offset encoder, sedanghan untuk rangkaian Quadrature Phase modulator terdiri dari 2 buah D flip-flop 7474 dan 2 buah XOR. Rangkaian Demodulator sebagai phase comparator digunakan juga 2 buah D flip-flop 7474 dan sebagai pembalik fasa 90° juga menggunakan 2 buah D flip-f Lop 7474. Untuk digunakan sebagai demodulator dengan pendeksian secara deferensial (Defferential Detection), rangkaian penunda cukup menggunakan beberapa shift register. Untuk menghindari Intersymbol Interference (ISI) akibat adanya batasan karena ketidak linearan transponder dan rangkaian band pass filter di penerima bila digunakan pada komunikasi satelit, pada rangkaian demodulator pencuplikan dapat diatur dengan mudah dan tepat dengan menggunakan rangkaian multivibrator 74123."

"Ground Communication system adalah sistem komunikasi darat. artinya : Suatu sistem komunikasi dare darat ke darat yang digunakan oleh pengguna di Iingkungan bandara. Dalam makalah tugas akhir ini penggunanya ialah unit-unit operasional yang ada di lingkungan Bandara Internasional HANG NADIM BATAM di Pulau Batam. Sistem ini bekerja secara otomatis. Sejak sinyal suara dikirimkan dengan menekan tombol PTT pada peralatan portable, lalu sinyal diterima oleh Rx ke Antena di Base Stasiun Repeater, kemudian sinyal dilanjutkan untuk proses management data, proses pencatatan data, penyimpanan dalam logging recorder untuk fungsi billing dan lain-lain. Sistim komunikasi darat ini memiliki sistem manager terminal yang mengatur management data. Selain itu memiliki juga sistem pemelihara / maintenance, sistem pewaktuan untuk mencatat air time, sistem pengontrolan dan lain-lain. Dalam tugas akhir ini, dibahas mengenai konsep trunking dan sistem peralatan secara keseluruhan. Sistem ini terbagi dua, yaitu : sistem pemakai dan sistem komponen. Sistem Pemakai di sini ialah pengguna dare sistem tersebut yaitu pemakai portable dan pemakai mobile. Sedangkan sistem komponen adalah komponen-komponen yang digunakan untuk menjalankan sistem. Sedangkan sistem akses yang digunakan adalah TDMA. Dalam TDMA aliran digital dibagi rata oleh sejumlah pemakai dengan menyediakan interval waktu yang sudah tertentu yang disebut time slot untuk tiap-tiap pemakai. Satu atau Iebih time slot yang digunakan untuk group pemakai secara tipikal diatur ke dalam frame. Selanjutnya diiaksanakan analisa untuk menguji data acuan sistem manual yang digunakan dalam apiikasi sistem komunikasi darat tersebut secara matematis melalui studi literature."

"Principles of mobile communication, is an authoritative treatment of the fundamentals of mobile communications. This book stresses the "fundamentals" of physical-layer wireless and mobile communications engineering that are important for the design of "any" wireless system. This book differs from others in the field by stressing mathematical modeling and analysis. It includes many detailed derivations from first principles, extensive literature references, and provides a level of depth that is necessary for graduate students wishing to pursue research on this topic. The book's focus will benefit students taking formal instruction and practicing engineers who are likely to already have familiarity with the standards and are seeking to increase their knowledge of this important subject. "