71 |
Differentiated service support in optical burst switching WDM networksLiu, David Q. January 2003 (has links)
Thesis (Ph. D.)--Ohio State University, 2003. / Title from first page of PDF file. Document formatted into pages; contains xxvii, 229 p. : ill. Advisor: Ming-Tsan Mike Liu, Department of Computer and Information Science. Includes bibliographical references (p. 219-229).
|
72 |
Multimode wavelength division multiplexing and demultiplexing using substrate-guided waves and volume holographic gratings /Zhou, Chuang. January 1998 (has links)
Thesis (Ph. D.)--University of Texas at Austin, 1998. / Vita. Includes bibliographical references (leaves 110-123). Available also in a digital version from Dissertation Abstracts.
|
73 |
Noise and crosstalk analysis of all-optical time division demultiplexersCheung, Chin Ying January 2001 (has links)
Bandwidth limitation of conventional electrical demultiplexer restricts the data capacity of long-haul optical time division multiplexing (OTDM) systems. It is desirable to demultiplex the OTDM signal in optical domain, thereby lifting the bandwidth limitation of the electrical demultiplexer. The general principle of all-optical time division demultiplexing is to effect asymmetric changes to the optical properties of the target and non-target channels. The different optical properties of the target and non-target channels facilitate the separation of the target channel(s) from the aggregate OTDM signal. The change of optical properties of the OTDM signal can be achieved by exploiting various types of nonlinear optics effects, such as cross-phase modulation and four-wave mixing. Although the technical viability of all-optical demultiplexing has been successfully demonstrated in laboratories, there is still a lack of understanding regarding the noise and crosstalk characteristics of all-optical demultiplexers. This PhD study attempts to investigate noise and crosstalk performance of two types of all-optical time division demultiplexers, namely nonlinear optical loop mirror (NOLM) and terahertz optical asymmetric demultiplexer (TOAD). In order to evaluate the noise and crosstalk performance of NOLM and TOAD demultiplexers, mathematical models are developed to simulate the transmission window for demultiplexing the target channel. The shape of the transmission window is dependent on the device parameters of the demultiplexers. Varying input parameters of the mathematical models can simulate the effects of changing device parameters on the transmission window. Nevertheless, it is onerous to calculate transmission windows for infinite combinations of device parameters. To simplify the noise and crosstalk analysis, device parameters of NOLM and TOAD demultiplexers are optimised for maximising the peak of the transmission windows. Noise and crosstalk models are also developed forNOLM and TOAD demultiplexers. The optimised device parameters of NOLM and TOAD demultiplexers are fed into the noise and crosstalk models for analysis. Simulation results show that a tradeoff between noise and crosstalk exists for the two types of demultiplexers. Device parameters can be optimised to minimise either noise or crosstalk, but not both. Finally, the noise and crosstalk models are connected to a receiver model, where the bit-error-rate (BER) performance of OTDM systems is evaluated. The BER performances of the NOLM and TOAD demultiplexing are compared using the optimised device parameters. It is found that TOAD has a slightly better BER performance compared with NOLM for lower baseband bit rate (i.e. a larger number of OTDM channels for an aggregate bit rate).
|
74 |
Code Division Multiplexing of Fiber Optic and Microelectromechanical Systems (MEMS) SensorsJacobson, Carl P. 10 May 2000 (has links)
Multiplexing has evolved over the years from Emile Baudot's method of transmitting six simultaneous telegraph signals over one wire to the high-speed mixed-signal communications systems that are now commonplace. The evolution started with multiplexing identical information sources, such as plain old telephone service (POTS) devices. Recently, however, methods to combine signals from different information sources, such as telephone and video signals for example, have required new approaches to the development of software and hardware, and fundamental changes in the way we envision the basic block diagrams of communication systems. The importance of multiplexing cannot be overstated. To say that much of the current economic and technological progress worldwide is due in part to mixed-signal communications systems would not be incorrect.
Along the vein of advancing the state-of-the-art, this dissertation research addresses a new area of multiplexing by taking a novel approach to network different-type sensors using software and signal processing. Two different sensor types were selected, fiber optics and MEMS, and were networked using code division multiplexing. The experimentation showed that the interconnection of these sensors using code division multiplexing was feasible and that the mixed signal demultiplexing software unique to this research allowed the disparate signals to be discerned. An analysis of an expanded system was performed with the results showing that the ultimate number of sensors that could be multiplexed with this technique ranges from the hundreds into the millions, depending on the specific design parameters used. Predictions about next-next generation systems using the techniques developed in the research are presented. / Ph. D.
|
75 |
THE BRIDGE FUNCTION TELEMETRY SYSTEMQishan, Zhang 11 1900 (has links)
International Telemetering Conference Proceedings / November 04-07, 1991 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Based on the theory of orthogonality, two orthogonal multiplex systems called frequency division multiplexing(FDM) and time division multiplexing(TDM) have long been developed. Therefore, many people tend to think that these two systems represent the ONLY two multiplexing methods that satisfy the orthogonal condition. However, after years of research, we've discovered a new kind of orthogonal functions called Bridge functions. The Bridge functions have the every promise of being the basis for constructing an entirely new kind of telemetry system, which has been named as sequency division multiplexing(SDM).
Since the Bridge functions are the mathematical basis of the new telemetry system, we will give a summary of the Bridge functions at first. We have successfully constructed an experimental prototype called BAM-FM system in our laboratory. The main ideas, block diagram, operational principles, and technical problems are discussed in this paper. All our work has proved that SDM has not only research interests, but also practical value.
|
76 |
THE BRIDGE FUNCTION TELEMETRY SYSTEMQishan, Zhang 11 1900 (has links)
International Telemetering Conference Proceedings / November 04-07, 1991 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Based on the theory of orthogonality, two orthogonal
multiplex systems called frequency division
multiplexing (FDM) and time division multiplexing (TDM) have
long been developed. Therefore, many people tend to think
that these two systems represent the ONLY two multiplexing
methods that satisfy the orthogonal condition. However,
after years of research, we've discovered a new kind of
orthogonal functions called Bridge functions. The Bridge
functions have the every promise of being the basis for
constructing an entirely new kind of telemetry system, which
has been named as sequency division multiplexing (SDM).
Since the Bridge functions are the mathematical basis of the
new telemetry system, we will give a summary of the Bridge
functions at first. We have successfully constructed an
experimental prototype called BAM-FM system in our
laboratory. The main ideas, block diagram, operational
principles, and technical problems are discussed in this
paper. All our work has proved that SDM has not only
research interests, but also practical value.
|
77 |
TELEMETRY TRANSMISSION USING INVERSE MULTIPLEXING AND ASYNCHRONOUS TRANSFER MODE (ATM)Eslinger, Brian, McCombe, Joleen 10 1900 (has links)
International Telemetering Conference Proceedings / October 27-30, 1997 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The growing need to transmit larger telemetry streams from the receiving site to the
processor location over greater distances is requiring newer and more creative techniques.
This paper reports efforts to use Asynchronous Transfer Mode (ATM) technology and
inverse multiplexing to provide an economical system to interface telemetry streams into
the public network for reliable transmission. Cost savings are available immediately for
programs that are willing to meet the synchronization criteria today. Lab testing has shown
the feasibility of using cost efficient techniques for data transmission.
This document describes the investigation that is currently underway that could provide a
significant change to the way telemetry data is transmitted from receiver sites to data
processing sites. Instead of using dedicated lines with dedicated bandwidth regardless of
the program being supported, the approach that has been tested in a lab environment would
allow the dynamic allocation of bandwidth using ATM over a variety of carrier services.
The combination of ATM and inverse multiplexing allows telemetry data rates above 1.5
Megabits per second (Mbps) to be transmitted over multiple T1 (1.544 Mbps) lines.
Previously, the only choice when data rates exceeded 1.5 Mbps was to use an entire DS-3
(45 Mbps). Now it is possible to transmit intermediate sized data rates (1.5 to 8 Mbps) by
bonding multiple T1s to provide the desired data throughput.
|
78 |
Cyclic prefix in OFDM systemsChen, Zhiqiang, 陳志強 January 2007 (has links)
published_or_final_version / abstract / Electrical and Electronic Engineering / Doctoral / Doctor of Philosophy
|
79 |
Symbol synchronization in OFDM-based systemsPan, Xinyue., 潘新月. January 2007 (has links)
published_or_final_version / Electrical and Electronic Engineering / Master / Master of Philosophy
|
80 |
Novel schemes for time-division-multiplexing of high-speed optical signals.January 1995 (has links)
by Ka Suen Lee. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1995. / Includes bibliographical references. / Chapter Chapter I --- Introduction --- p.1 / Chapter 1.1 --- The evolution of communication networks --- p.1 / Chapter 1.2 --- The development of lightwave communication systems --- p.2 / Chapter 1.3 --- System architecture --- p.9 / Chapter 1.4 --- The motivation of the researches --- p.11 / References --- p.13 / Chapter Chapter II --- Theories --- p.15 / Chapter 2.1 --- The optical time-division multiple-access --- p.15 / Chapter 2.2 --- The operations of 2 x 2 fiber coupler --- p.18 / References --- p.21 / Chapter Chapter III --- Optical loop mirror multiplexer --- p.23 / Chapter 3.1 --- Self Phase Modulation in optical fiber --- p.23 / Chapter 3.2 --- Current developments of the optical loop mirror --- p.24 / Chapter 3.3 --- The principle of the novel time-division multiplexer --- p.30 / Chapter 3.4 --- The experiment and results --- p.31 / Chapter 3.5 --- Analysis on the splitting ratios of the optical loop mirror multiplexer --- p.34 / Chapter 3.6 --- Analysis on the phase of the optical outputs --- p.36 / Chapter 3.7 --- The theories of the optical loop mirror multiplexer --- p.39 / Chapter 3.8 --- The advantages on the optical loop mirror multiplexer --- p.41 / Chapter 3.9 --- The optical bit pattern generation --- p.48 / Chapter 3.10 --- The conclusions of the optical loop mirror multiplexer --- p.49 / References --- p.51 / Chapter Chapter IV --- Optical matrix for high-speed operation in two-dimensional array devices --- p.55 / Chapter 4.1 --- Recent developments in two-dimensional array devices --- p.55 / Chapter 4.2 --- The principle of the novel optical matrix --- p.58 / Chapter 4.3 --- The experiment and results --- p.62 / Chapter 4.4 --- The applications of the novel optical matrix --- p.66 / Chapter 4.5 --- Comparison on the operation modes of the optical matrix --- p.74 / Chapter 4.6 --- Comparison on the construction of the optical matrix --- p.77 / Chapter 4.7 --- The conclusions of the optical matrix --- p.80 / References --- p.81 / Chapter Chapter V --- Conclusions and Future Works --- p.84 / Chapter 5.1 --- The conclusions --- p.84 / Chapter 5.2 --- The future works --- p.86 / Chapter 5.3 --- List of publications --- p.87 / References --- p.88 / Appendix 1 The 1.319 μm Nd:YAG laser system --- p.A-l / Chapter A1.1 --- The laser action of the Neodymium-YAG solid-state laser --- p.A-l / Chapter A1.2 --- The four-level laser system --- p.A-4 / Chapter A1.3 --- The installation and operations of a 1.319μm Nd:YAG laser --- p.A-8 / References --- p.A-21 / Appendix 2 Mode-locking in the Nd:YAG Laser --- p.A-22 / Chapter A2.1 --- The mode-locking technique --- p.A-22 / References --- p.A-26
|
Page generated in 0.0343 seconds