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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.
21

It´s All Relative: Time and Space in Nabokov´s Lolita

Preston, Robert January 2013 (has links)
This essay offers a deconstructive approach to Nabokov´s Lolita. Critics have tended to treat space and time as distinct concepts in the novel: choosing to analyse the role of either one or the other, and even when considering both, examining them in isolation. It´s narrator, Humbert Humbert, however, implies that "time" and "spatial" terms are interchangeable in a way reminiscent of Einstein´s Theory of Relativity in which space-time is a continuum that is experienced relative to the individual observer´s own position in the universe. This essay therefore explores the possibility that Nabokov may have used Einstein´s concept of space-time relativity as a metaphor in Lolita. The essay looks first at the various ways in which the idea of relativity surfaces throughout the novel not just in relation to space and time, but also in its moral, cultural and historic forms. The roles of the Hour Glass Lake, Lolita´s sunglasses and Humbert´s car, three of the novel´s chief symbols, are then discussed in relation to its key elements: the notion of time dilation, the place of the observer and Humbert´s space-time bubble. It next concentrates on how the characters in the novel exemplify the roles of both observer and observed in a modern, self-centred and morally relativistic world. The final section argues that Humbert’s "madness" represents the most extreme consequence of his living in his own solipsistic bubble of space-time, or "dream vacuum" as he calls it.
22

Space-time Coded Systems with Continuous Phase Modulation

Maw, Rachel Leigh January 2007 (has links)
Space-time coded systems developed in the last ten years have been designed primarily using linear modulation. Non-linear continuous phase modulation has desirable constant envelope properties and considerable potential in space-time coded systems. The work in this thesis is focussed on developing and analysing an integrated space-time coded continuous phase modulated (STC-CPM) system. The coding of the space-time encoder and the modulation is incorporated into a single trellis encoder. This allows state combining, which leads to complexity reduction due to the reduced number of states. Design criteria for STC-CPM are summarized and the Euclidean distance is shown to be important for code design. The integrated STC-CPM system design enables systematic spacetime code searches that find optimal space-time codes, to be easily implemented. Optimal rate-1/2 and rate-2/3 space-time codes are found by maximizing the system's minimum squared Euclidean distance. These codes can provide high throughput and good coding gains over un-optimized full rank codes, such as delay diversity, in a quasi-static flat fading environment. Performance bounds are developed using a union bound argument and the pairwise error probability. Approximations of the bounds are evaluated. These truncated upper bounds predict the slopes of the simulated performance curves at low error rates.
23

Error-rate evaluation and optimization for space-time codes

Zhang, Zhi, January 2007 (has links)
Thesis (Ph. D.)--University of Hong Kong, 2008. / Also available in print.
24

Space-time code designs and fast decoding for MIMO and cooperative communication systems

Shang, Yue. January 2009 (has links)
Thesis (Ph.D.)--University of Delaware, 2008. / Principal faculty advisor: Xiang-Gen Xia, Dept. of Electrical & Computer Engineering. Includes bibliographical references.
25

Differential and coherent detection schemes for space-time block codes/

Oruç, Özgür. Altınkaya, Mustafa Aziz January 2002 (has links) (PDF)
Thesis (Master)--İzmir Institute of Technology, İzmir, 2002 / Includes bibliographical references (leaves. 90-94).
26

A comparison of frequency offset estimation methods in Orthogonal Frequency Division Multiplexing (OFDM) systems /

Karaoglu, Bulent. January 2004 (has links) (PDF)
Thesis (M.S. in Electrical Engineering)--Naval Postgraduate School, Dec. 2004. / Thesis Advisor(s): Roberto Cristi, Murali Tummala. Includes bibliographical references (p. 45-46). Also available online.
27

Simulation performance of multiple-input multiple-output systems employing single-carrier modulation and orthogonal frequency division multiplexing /

Saglam, Halil Derya. January 2004 (has links) (PDF)
Thesis (M.S. in Electrical Engineering)--Naval Postgraduate School, Dec. 2004. / Thesis advisor(s): Murali Tummala, Roberto Cristi. Includes bibliographical references (p. 69-71). Also available online.
28

Space-time block codes with low maximum-likelihood decoding complexity

Sinnokrot, Mohanned Omar. January 2009 (has links)
Thesis (Ph.D)--Electrical and Computer Engineering, Georgia Institute of Technology, 2010. / Committee Chair: Barry, John; Committee Co-Chair: Madisetti, Vijay; Committee Member: Andrew, Alfred; Committee Member: Li, Ye; Committee Member: Ma, Xiaoli; Committee Member: Stuber, Gordon. Part of the SMARTech Electronic Thesis and Dissertation Collection.
29

Space-time turbo coding for CDMA mobile communications

Van Wyk, Daniel Jacobus. January 2000 (has links)
Thesis (D.Phil.(Electronic Engineering))--University of Pretoria, 2000. / Includes summary in Afrikaans and English. Includes bibliographical references (leaves 113-119).
30

Space-Time Coding for Polynomial Phase Modulated Signals

Granados, Omar D 01 April 2011 (has links)
Polynomial phase modulated (PPM) signals have been shown to provide improved error rate performance with respect to conventional modulation formats under additive white Gaussian noise and fading channels in single-input single-output (SISO) communication systems. In this dissertation, systems with two and four transmit antennas using PPM signals were presented. In both cases we employed full-rate space-time block codes in order to take advantage of the multipath channel. For two transmit antennas, we used the orthogonal space-time block code (OSTBC) proposed by Alamouti and performed symbol-wise decoding by estimating the phase coefficients of the PPM signal using three different methods: maximum-likelihood (ML), sub-optimal ML (S-ML) and the high-order ambiguity function (HAF). In the case of four transmit antennas, we used the full-rate quasi-OSTBC (QOSTBC) proposed by Jafarkhani. However, in order to ensure the best error rate performance, PPM signals were selected such as to maximize the QOSTBC’s minimum coding gain distance (CGD). Since this method does not always provide a unique solution, an additional criterion known as maximum channel interference coefficient (CIC) was proposed. Through Monte Carlo simulations it was shown that by using QOSTBCs along with the properly selected PPM constellations based on the CGD and CIC criteria, full diversity in flat fading channels and thus, low BER at high signal-to-noise ratios (SNR) can be ensured. Lastly, the performance of symbol-wise decoding for QOSTBCs was evaluated. In this case a quasi zero-forcing method was used to decouple the received signal and it was shown that although this technique reduces the decoding complexity of the system, there is a penalty to be paid in terms of error rate performance at high SNRs.

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