Spelling suggestions: "subject:"enmodulation (electronics"" "subject:"enmodulation (delectronics""
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Radio frequency photonic in-phase and quadrature-phase vector modulationDavis, Kyle 13 January 2014 (has links)
The focus of this thesis is to investigate the implementation of Radio Frequency (RF) In-Phase and Quadrature-Phase (I/Q) vector modulation through the use of modern photonic components and sub-systems which offer extremely wide RF intrinsic bandwidths. All-electronic vector modulators suffer from frequency coverage limitations and amplitude and phase instability due to components such as phase shifters and variable gain controllers operating at or near 100\% bandwidth. In stark contrast, once an RF signal has been modulated onto an optical carrier, the percent bandwidth of the RF to carrier is typically less than 0.01\% percent.
The fundamental mechanisms and basic electronic and photonic components needed to achieve vector modulation is introduced first. The primary electrical component required in most architectures is the 90° RF hybrid coupler, which is required to generate the RF I and Q terms. The two primary photonic building blocks, aside from the laser, electro-optic modulator and demodulator, are Mach-Zehnder Modulators (MZM) and Variable Optical Attenuators (VOA). Through the utilization of these components, multiple past architectures are explored and multiple new architectures are designed simulated.
For each architecture, there is a discussion on the practical implementation. Considerations such as system complexity, integration, and sensitivity to unwanted environmental stimuli are taken into account with potential solutions to alleviate these risks. In closing, the noise figure and its impact on Spur-Free Dynamic Range (SFDR) for a basic RF photonic link is derived to provide a system-level figure of merit that can be used, in most RF applications, to determine the overall performance utility current and future designs.
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Data compression with particular applications to video signals.Tsui, Stephen S. T. January 1972 (has links)
No description available.
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Advanced modulation formats for high-bit-rate optical networksHaris, Muhammad 07 May 2008 (has links)
The objective of the proposed research is to investigate the performance of advanced modulation formats, specifically modified duobinary return-to zero (MD-RZ) modulation scheme and its long-haul repeaterless transmission over standard single mode fiber (SMF). This research also focuses on phase modulation formats like differential phase shift keying (DPSK) and differential quadrature phase shift keying (DQPSK), specifically free spectral range (FSR) optimization and wavelength offset tolerance in direct detection of these phase modulated systems. In this research we present a novel and cost effective technique to generate a modified duobinary return-to-zero (MD-RZ) signal. Next, we attained experimental results for single channel and WDM repeaterless transmission using these MD-RZ signals. A numerical comparison is also drawn with other conventional MD-RZ transmitters. MD-RZ transmission characteristics are also studied numerically for 40 Gb/s WDM signals and compared with other two leading constant intensity phase modulated formats like DPSK and DQPSK. We also have presented experimental results for FSR optimization of DQPSK de-modulator for ultra-high data-rate systems in the presence of strong optical filtering. Choice of an optimal FSR beyond 1-bit delay in Mach-Zehnder delay interferometer (MZ-DI) helps relieving some of the degradations due to strong optical filtering. Wavelength offset tolerance is also experimentally measured and numerically investigated for DPSK and DQPSK modulation formats with different transmitter schemes employing intensity or phase modulators to achieve required phase shifts.
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Turbo implementation of high dimensional trellis-coded modulationWang, Mingjing. January 2001 (has links)
Thesis (M.S.)--Ohio University, 2001. / Title from PDF t.p.
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An accurate CMOS four-quadrant analog multiplierGottiparthy, Ramraj, Wilamowski, Bogdan M. January 2006 (has links) (PDF)
Thesis(M.S.)--Auburn University, 2006. / Abstract. Vita. Includes bibliographic references.
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High efficiency delta-sigma modulation data converters /Lee, Kyehyung. January 1900 (has links)
Thesis (Ph. D.)--Oregon State University, 2008. / Printout. Includes bibliographical references. Also available on the World Wide Web.
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Optimization of bit interleaved coded modulation using genetic algorithmsDoppalapudi, Raghu Chaitanya. January 1900 (has links)
Thesis (M.S.)--West Virginia University, 2008. / Title from document title page. Document formatted into pages; contains ix, 55 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 53-55).
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Development of a gigawatt repetitive pulse modulator and high-pressure switch test stand and results from high-pressure switch testsNorgard, Peter. January 2006 (has links)
Thesis (M.S.)--University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on April 22, 2009) Includes bibliographical references.
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Link adaptation techniques for cellular fixed broadband wireless access systems /Armanious, Ehab January 1900 (has links)
Thesis (M. App. Sc.)--Carleton University, 2003. / Includes bibliographical references (p. 95-97). Also available in electronic format on the Internet.
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Automatic recognition and demodulation of digitally modulated communications signals using wavelet-domain signaturesHo, Ka Mun. January 2010 (has links)
Thesis (Ph. D.)--Rutgers University, 2010. / "Graduate Program in Electrical and Computer Engineering." Includes bibliographical references (p. 183-189).
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