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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Analysis of frequency conversion for M-QAM and M-PSK modems

Wojtiuk, Jeffrey John Unknown Date (has links)
Thesis (M.Eng.)--University of South Australia, 1995
32

Analysis of frequency conversion for M-QAM and M-PSK modems

Wojtiuk, Jeffrey John Unknown Date (has links)
Thesis (M.Eng.)--University of South Australia, 1995
33

Performance and distance spectrum calculation of TCM over ISI channels

Nam Van Tran Unknown Date (has links)
Thesis (MEng) -- University of South Australia, 1998
34

Speech synthesis using a digital modulation scheme on the IBM personal computer

Wallace, John Glenn, January 1989 (has links) (PDF)
Thesis (M.S.)--University of Missouri--Rolla, 1989. / Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed January 9, 2009) Includes bibliographical references (p. 39-40).
35

Adaptive power amplifier linearization by digital pre-distortion with narrowband feedback using genetic algorithms

Sperlich, Roland. January 2005 (has links)
Thesis (Ph. D.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2006. / Leach, William M., Committee Member ; Sills, James A., Committee Member ; Kenney, J. Stevenson, Committee Chair ; Zhou, G. Tong, Committee Co-Chair ; Fenney, Robert K., Committee Member.
36

Estudo e caracterização experimental de modulador óptico em quadratura utilizando sinais em contra-fase / Theoretical and experimental characterization of quadrature optical modulators using opposed-phase signals

Sutili, Tiago, 1988- 25 August 2018 (has links)
Orientador: Evandro Conforti / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-25T18:04:45Z (GMT). No. of bitstreams: 1 Sutili_Tiago_M.pdf: 6836579 bytes, checksum: 486af2d6a44ce1e40f15577d8f677d88 (MD5) Previous issue date: 2014 / Resumo: A crescente demanda do mercado por um maior aproveitamento da capacidade de transmissão dos sistemas ópticos faz com que técnicas de modulação avançadas sejam cada vez mais consideradas em aplicações práticas. Dentre suas vantagens, tem-se uma melhora significativa na eficiência espectral, na resistência contra diversos efeitos não-lineares e fontes de ruído, assim como uma diminuição na frequência de operação da eletrônica empregada no sistema. Com isso em vista, buscou-se a realização de uma análise completa das principais propriedades de diversas técnicas de modulações avançadas, baseadas na manipulação tanto da amplitude como da fase do sinal óptico e utilizadas em conjunto com sistemas de multiplexação por polarização e comprimento de onda. Nos testes laboratoriais, o objetivo foi a caracterização de um Modulador IQ, responsável pela geração de sinais modulados em 64QAM, 16QAM e DQPSK, bem como de diversos outros componentes necessários para a implementação de um sistema de comunicação óptico coerente completo. Dessa forma, a estrutura básica do sistema foi analisada e compreendida para que em trabalhos futuros sua implementação seja concluída e testes mais detalhados possam ser realizados / Abstract: The market¿s increasing demand for high capability optical systems requested advanced modulation techniques considered in practical applications. Among its advantages, a significant improvement in spectral efficiency, immunity against various nonlinear effects and noise sources were obtained with a decrease in the operation frequency of the electronics. With that in mind, we sought to conduct an analysis throughout the key properties of various advanced modulation techniques, based on the manipulation of both the amplitude and the phase of the optical signal, and used together with multiplexing systems for polarization and wavelength. Many laboratory tests were made with the objective of characterizing an IQ Modulator, responsible for generating DQPSK, 16-QAM and 64-QAM signals, as well as many other components required for the implementation of a complete coherent optical communication system. Thus achieving the understanding of the system¿s basic structure, the realization of a more complete and detailed set of tests will be possible / Mestrado / Telecomunicações e Telemática / Mestre em Engenharia Elétrica
37

TIME REFERENCE SYSTEM OF THE ESO VERY LARGE TELESCOPE.

Lange, Werner R., Ravensbergen, Martin 11 1900 (has links)
International Telemetering Conference Proceedings / October 30-November 02, 1995 / Riviera Hotel, Las Vegas, Nevada / The necessity of supplying precise time information in large telemetry ground stations and astronomical observatories is very similar. Therefore the way of solving this problem as it is done in the Very Large Telescope of the European Southern Observatory can be easily adopted to telemetry stations and ranges, especially when fiber optics are used. The European Southern Observatory (ESO) is building a new observatory in Chile for the Very Large Telescope (VLT). This VLT consists of 4 telescopes, each of them has a primary mirror diameter of 8 meters. the control architecture is based on workstations and VMEbus computers. The VMEbus computers are distributed over the whole building and are using real time operating system. Since the availability of the Global Positioning System (GPS) the generation of highly accurate timing signals on remote locations without the use of expensive Cesium standards does not create problems any more. However, distribution of a timing signal to many computer with high accuracy is an issue. The accuracy of the commonly used IRIG B-code is not adequate if the requirements are in the 10 microseconds range. This paper presents the design of a timing system that is adopted to the VLT. An overview of the requirements of the Time Reference System (TRS) is given. These requirements have been defined on the basis of experiences with the timing system of the ESO NTT telescope. The hardware units are described. These are a Central Time Standard, a Time Distribution System and a VME Time Interface Module. The distribution is based on fiber optic transmission, using a simple digital modulation that outperforms the analog IRIG B modulation. The Time Interface Module in the computer does not only perform the timing signal decoding but contains also user-programmable timers that are synchronously clocked from the time source. Presently all units of the TRS have been tested and the series production of the distribution and the Time Interface Modules are in progress.
38

Implementation and comparison of the Golay and first order Reed-Muller codes

Unknown Date (has links)
In this project we perform data transmission across noisy channels and recover the message first by using the Golay code, and then by using the first-order Reed- Muller code. The main objective of this thesis is to determine which code among the above two is more efficient for text message transmission by applying the two codes to exactly the same data with the same channel error bit probabilities. We use the comparison of the error-correcting capability and the practical speed of the Golay code and the first-order Reed-Muller code to meet our goal. / by Olga Shukina. / Thesis (M.S.)--Florida Atlantic University, 2013. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.
39

Trellis-coded quantization with unequal distortion.

January 2001 (has links)
Kwong Cheuk Fai. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 72-74). / Abstracts in English and Chinese. / Acknowledgements --- p.i / Abstract --- p.ii / Table of Contents --- p.iv / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Quantization --- p.2 / Chapter 1.2 --- Trellis-Coded Quantization --- p.3 / Chapter 1.3 --- Thesis Organization --- p.4 / Chapter 2 --- Trellis-Coded Modulation --- p.6 / Chapter 2.1 --- Convolutional Codes --- p.7 / Chapter 2.1.1 --- Generator Polynomials and Generator Matrix --- p.9 / Chapter 2.1.2 --- Circuit Diagram --- p.10 / Chapter 2.1.3 --- State Transition Diagram --- p.11 / Chapter 2.1.4 --- Trellis Diagram --- p.12 / Chapter 2.2 --- Trellis-Coded Modulation --- p.13 / Chapter 2.2.1 --- Uncoded Transmission verses TCM --- p.14 / Chapter 2.2.2 --- Trellis Representation --- p.17 / Chapter 2.2.3 --- Ungerboeck Codes --- p.18 / Chapter 2.2.4 --- Set Partitioning --- p.19 / Chapter 2.2.5 --- Decoding for TCM --- p.22 / Chapter 3 --- Trellis-Coded Quantization --- p.26 / Chapter 3.1 --- Scalar Trellis-Coded Quantization --- p.26 / Chapter 3.2 --- Trellis-Coded Vector Quantization --- p.31 / Chapter 3.2.1 --- Set Partitioning in TCVQ --- p.33 / Chapter 3.2.2 --- Codebook Optimization --- p.34 / Chapter 3.2.3 --- Numerical Data and Discussions --- p.35 / Chapter 4 --- Trellis-Coded Quantization with Unequal Distortion --- p.38 / Chapter 4.1 --- Design Procedures --- p.40 / Chapter 4.2 --- Fine and Coarse Codebooks --- p.41 / Chapter 4.3 --- Set Partitioning --- p.44 / Chapter 4.4 --- Codebook Optimization --- p.45 / Chapter 4.5 --- Decoding for Unequal Distortion TCVQ --- p.46 / Chapter 5 --- Unequal Distortion TCVQ on Memoryless Gaussian Source --- p.47 / Chapter 5.1 --- Memoryless Gaussian Source --- p.49 / Chapter 5.2 --- Set Partitioning of Codewords of Memoryless Gaussian Source --- p.49 / Chapter 5.3 --- Numerical Results and Discussions --- p.51 / Chapter 6 --- Unequal Distortion TCVQ on Markov Gaussian Source --- p.57 / Chapter 6.1 --- Markov Gaussian Source --- p.57 / Chapter 6.2 --- Set Partitioning of Codewords of Markov Gaussian Source --- p.58 / Chapter 6.3 --- Numerical Results and Discussions --- p.59 / Chapter 7 --- Conclusions --- p.70 / Bibliography --- p.72
40

Amplifier linearization by using the generalized baseband signal injection method.

January 2002 (has links)
Leung Chi-Shuen. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 82-89). / Abstracts in English and Chinese. / Chapter Chapter 1 --- Introduction --- p.1 / Chapter Chapter 2 --- Review of Linearization Techniques --- p.4 / Chapter 2.1 --- Feedforward --- p.5 / Chapter 2.2 --- Feedback --- p.7 / Chapter 2.3 --- Predistortion --- p.10 / Chapter Chapter 3 --- The Volterra Series Method for Nonlinear Analysis --- p.12 / Chapter 3.1 --- Volterra Series Method --- p.13 / Chapter 3.2 --- Nonlinear Transfer Function --- p.14 / Chapter 3.3 --- Weakly Nonlinear Approximation --- p.18 / Chapter 3.4 --- Nonlinear Modeling --- p.19 / Chapter 3.5 --- Determination of Nonlinear Transfer Function --- p.22 / Chapter Chapter 4 --- Manifestation of Nonlinear Behavior --- p.25 / Chapter 4.1 --- Two-Tone Volterra Series Analysis --- p.25 / Chapter 4.2 --- Harmonic Distortion --- p.28 / Chapter 4.3 --- AM/AM and AM/PM --- p.29 / Chapter 4.4 --- Intermodulation Distortion --- p.31 / Chapter Chapter 5 --- The Generalized Baseband Signal Injection Method --- p.33 / Chapter 5.1 --- Generalized Baseband Signal Injection Method (GM) --- p.34 / Chapter 5.2 --- Application of GM to Predistorter-Amplifier Linearization --- p.38 / Chapter 5.2.1 --- Case 1: Standalone Amplifier without Injection --- p.40 / Chapter 5.2.2 --- Case 2: Injection to Amplifier Only --- p.41 / Chapter 5.2.3 --- Case 3: Injection to Diode Predistorter Only --- p.41 / Chapter 5.2.4 --- Case 4: Injection to Both Diode Predistorter and Amplifier --- p.42 / Chapter 5.3 --- Application of GM to Multi-Stage Amplifier Linearization --- p.43 / Chapter 5.3.1 --- Case 1: Amplifying System with No Signal Injection --- p.46 / Chapter 5.3.2 --- Case 2: Amplifying System with Single Injection Point --- p.47 / Chapter 5.3.3 --- Case 3: Amplifying System with Two Injection Points --- p.48 / Chapter Chapter 6 --- Experimental Setup and Measurements --- p.50 / Chapter 6.1 --- Experimental Setup --- p.51 / Chapter 6.1.1 --- Diode Predistorter --- p.51 / Chapter 6.1.2 --- Small Signal Amplifier --- p.54 / Chapter 6.1.3 --- Medium Power Amplifier --- p.58 / Chapter 6.1.4 --- Baseband Signal Generation Circuit --- p.61 / Chapter 6.1.5 --- Baseband Amplifiers --- p.63 / Chapter 6.2 --- Linearization of Amplifier with Predistortion Circuitry --- p.65 / Chapter 6.2.1 --- Two-Tone Test --- p.65 / Chapter 6.2.2 --- Vector Signal Test --- p.68 / Chapter 6.2.3 --- Dynamic Range Evaluation --- p.70 / Chapter 6.3 --- Linearization of Multi-Stage Amplifying System --- p.71 / Chapter 6.3.1 --- Determination of Transfer and Gain Coefficients --- p.71 / Chapter 6.3.2 --- Two-Tone Test --- p.74 / Chapter 6.3.3 --- Vector Signal Test --- p.77 / Chapter 6.3.4 --- Dynamic Range Evaluation --- p.79 / Chapter Chapter 7 --- Conclusion and Future Work --- p.80 / References --- p.82 / Author's Publications --- p.90

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