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Abstrak :
Jaringan komunikasi dan informasi yang berkembang sekarang ini banyak menawarkan beragam jasa komunikasi seperti suara, data dan gambar. Komunikasi gambar, baik gambar diam maupun gambar bergerak harus diolah sehingga kapasitas memori dan lebar pita frekuensi (bandwidth) yang dibutuhkan dalam proses selanjutnya menjadi seminimal mungkin dengan mempertimbangkan kualitas dari gambar. Oleh sebab itulah dibutuhkan suatu teknik pemampatan sinyal gambar bergerak untuk mengatasi persoalan kapasitas memori dan bandwidth tersebut. Dalam sinyal gambar bergerak terdapat redundansi spasial dan redundansi temporal yang harus dikurangi oleh teknik pemampatan sinyal gambar bergerak. Dengan mengurangi redundansi ini diperoleh rasio pemampatan yang tinggi dengan kualitas gambar rekonstruksi yang baik. Dalam pemampatan sinyal gambar bergerak digunakan metode Predicted mumi dengan Motion Compensation dan metode MPEG1 dengan metode Predicted dan Interpolated untuk mengurangi redundansi spasial dan temporal tersebut.

Abstrak :
ABSTRAK ABSTRACT
The process of signal transmission from transmitter to receiver in a telecommunication system has some disturbance such as noise and multipath fading caused by reflection, scattering, or difraction. High data rate in the fading channel causes the channel coherent bandwidth becomes narrower compared to the signal bandwidth so that the channel has frequency selective fading. To overcome this problem, the multi carrier modulation technique is used with the aim to have a flat signal fading on each subcarrier. The well-known multi-carrier technique is Orthogonal Frequency Division Multiplex (OFDM). However, one of the drawbacks of this technique is the Peak to Average Power Ratio (PAPR) is high. PAPR is ratio between the peak power and the average power of the signal. High PAPR values causes degradation in system?s performance. This thesis designs and analyses PAPR reduction using wavelet transform and clipping techniques in order to obtain better PAPR reduction to improve the performance of OFDM system. The results of design and analysis show a significant reduction in PAPR value, especially when wavelet rbio3.7 and Deep Clipping techniques are used.

Abstrak :
Laporan ini berisi tentang salah satu aplikasi sistem embedded yaitu untuk menghangsilkan sinyal sembarang analog berbasis pewaktuan. Predasi yang dilakukan oleh ikan kembung terhadap kerang telah mengurangi jumlah produksi kerang. Untuk itu, diperlukan sebuah piranti yang efektif untuk menghalau ikan tersebut dari area pengumpulan kerang. Pendekatan yang dilakukan adalah mengaplikasikan teknologi suara bawah laut dengan pembangkit sinyal yang bekerja secara otonom. Sebagai penghasil sinyal, saya menggunakan development kit EFM32 berbasis mikrokontroler CORTEX M3. Karakter sinyal adalah sembarang dan dipancarkan oleh pengeras suara bawah air. Piranti ini dapat dioperasikan oleh pengguna dengan mengatur saklar untuk menentukan frekuensi dan kemunculan sinyal tersebut. ......I have studied one of many applications of embedded system technology. Here I use it to produce repulsive random analog signal based on timing. Predation by bream shells disrupted the production of many shells. To solve this problem will require an effective tool to repel the sea bream. The approach I have used is to imply underwater sound technology using autonomous signal generator. To produce the signal, I have used EFM32 Development Kit that based on microcontroller CORTEX M3. The characteristic of signal is random and will be emitted by underwater speakers. The tool can be operated simply by using switch controller to adjust band frequency and recurrence of the signal.

Abstrak :
Skripsi ini membahas mengenai perancangan dekoder pada pengkodean suara VSELP. Proses dari pendekodean suara ini dimulai dari ekstraksi 27 parameter yang dikirimkan dari enkoder. Parameter - parameter ini kemudian diproses untuk mendapatkan sinyal sintesis. Namun, sinyal sintesis yang dihasilkan mengalami penurunan nilai SNR (Signal to Noise Ratio), tingkat noise yang tinggi mendekati white noise sehingga sangat sulit untuk menjaganya dibawah nilai ambang batas kemampuan suara yang dapat didengar yang dikarenakan terjadi penurunan laju bit. Untuk itu, diperlukannya filtering pada sinyal sintesis sehingga didapatkan kembali sinyal suara dengan kualitas yang baik. Dalam skripsi ini dilakukan simulasi pendekodean pada teknik pengkodean suara VSELP dengan bahasa pemograman Simulink MATLAB. Dari hasil simulasi didapatkan sinyal keluaran dekoder mengalami perlambatan dalam pelafalan kata yang disebabkan karena perbedaaan waktu pencuplikan antara sinyal suara asli dengan pencuplikan pada percobaan. Selain itu, proses simulasi membutuhkan waktu yang lama. Untuk mengatasinya algoritma proses decoder harus dipersingkat, kemampuan prosesor yang cepat harus dipergunakan dan menggunakan bahasa pemograman yang tidak dipengaruhi dengan waktu pencuplikan.

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This final project discusses about decoder design in VSELP speech coding. The process in decoder starts with the extraction of 27 parameter which is sent by the encoder. Then, these parameters is being processed to get synthesis speech signal However, the synthesis speech has high noise level approaching white noise, which makes it difficult to keep under the audible threshold value due to the decrease of bit rate. Therefore, the synthesis speech signal has to be filtered to obtain good quality synthesis speech signal. In this final project, the simulation is made to simulate the decoding process in VSELP speech coding with Simulink MATLAB programming language. From the simulation, the synthesis speech signal experiencing slowing output in the word pronunciation which caused by the difference sampling time between the real speech signal dan the sampling time used in decoder processing. Furthermore, the simulation process needs long time. To overcome these problem, the decoder process algorithm should be shortened, the ability of the processor which used must be fast and use use programming language that is not influenced with sampling time.

Abstrak :
The advantages optical fiber in communication field are widely utilized in developing steps from electrical communication to optical communication. Optical fiber communication promise extremely high data rate over long distance transmission without needing to amplify and retransmit along the way. It is well understood that if frequency of the transmitted signals. is increased some problems such as electromagnetic interferences. crosstalk and signal distortions will appear. Those difficulties can. be solved or eliminated by using optical fiber cable. instead of copper cable. Optical fiber used to transmit and to receive information signal mutinously was usually separated in difference fibers for transmitting and receiving direction. I n this thesis a bi-directional transmission system through a single fiber with same wavelength by the use of rod lenses was constructed. A simple circuit design techniques have been used in order to make transmitter and receiver. To combine and to separate transmitter and receiver in each side to and from the fiber, two quarter-pitch GRIN rod lenses functioning as optical directional coupler was used. The result of the experiment as a model of bi-directional optical communication system shows a good performance with an appropriate reliability. The measurement results of power distribution loss. crosstalk and signal transmission quality that have been evaluated to conclude the entire result.