Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 23 for “"on-off keying"”.
-
All-optical 2r regenerator based on self-phase modulation
Nowadays, optical regeneration is getting popularity as it provides an effective way of coping with transmission impairment. Transmission impairments degrade the quality of optical signals and thus, ultimately limiting the achievable transmission distance. Optical 2R regenerators provide an …
-
Analysis of digital communication signals and extraction of parameters
The signal classification performance of four types of Electronics Support Measure (ESM) Communications detection systems is compared from the standpoint of the unintended receiver (interceptor). Typical digital communication signals considered include Binary Phase Shift Keying (BPSK), Quadrature …
-
Spectrum Sensing in Cognitive Radio Networks
… emerged as an attractive wireless communication technology. This dissertation is concerned with developing spectrum sensing algorithms in cognitive radio networks where a single or multiple cognitive radios (CRs) assist in detecting licensed primary bands employed by single or multiple primary …
-
Linearly repeatered communication systems using optical amplifiers
… parameter in the design of optical communication systems. Prior results on receiver sensitivity for on-off keying modulated direct detection systems with an optical preamplifier are generalized for the cases of frequency-shift keying and subcarrier modulation. Our results, obtained by using the …
-
Low frequency cutoff effects in fiber optic communication systems
The presence of low frequency cutoffs in the forward path of the information signal leads to inter-symbol interference (ISI) and degradation of the signal to noise ratio at the sampling instant in digital on-off keying (OOK) systems. The low frequency cutoffs occur as a result of the presence of …
-
An energy efficient RF transceiver for wireless microsensor networks
A wireless microsensor network consists of a group of sensor nodes that are deployed remotely and used to relay sensing data to the end-user. Due to their remote deployment, large scale wireless sensor networks require a low-power, energy efficient transceiver that can operate for years on a single …
-
Low power rf transceivers
… at microwave frequencies. Hybrid prototypes and Monolithic Microwave Integrated Circuits (MMICs) which achieve power consumptions of less than 1 mW and theoretical operating ranges of over 10 m are described. The motivation behind the design of circuits exhibiting ultra low power consumption and, …
-
Performance analysis for near-field atmospheric optical communications
Establishing, high data rate communication links over short distances via fiber-optic cables may prove costly and time consuming, particularly in urban areas. Through-the-air optical communication systems are a reliable and cost effective alternative for establishing high data rate links when the …
-
Analysis and modeling of the effects of reflection induced noise on the performance of fiber optic communication systems
Refractive index discontinuities in fiber optic transmission systems are known to cause deleterious effects. Non-negligible return losses associated with connectors and splices in present day systems cause intermittent error bursts and bit-error-rate floors in gigabit per second systems. These are …
-
All-optical signal processing using cascaded quadratic interactions in periodically poled lithium niobate waveguides
… signal processing using cascaded quadratic nonlinearities in periodically poled lithium niobate (PPLN) waveguides for telecommunication applications. PPLN waveguides which possess high second-order nonlinearity are attractive due to their suitable properties with respect to high compactness, …
-
Analysis and design of wideband voltage controlled oscillators using self-oscillating active inductors.
Voltage controlled oscillators (VCOs) are essential components of RF circuits used in transmitters and receivers as sources of carrier waves with variable frequencies. This, together with a rapid development of microelectronic circuits, led to an extensive research on integrated implementations of …
-
Pre-compensation of nonlinear distortion of a silicon microring modulator in short reach systems
Silicon photonics has attracted significant attention due to its compatibility with CMOS technology and the potential for both discrete and integrated devices. As a critical component in silicon-based communication systems, silicon optical modulators have been widely investigated, including …
-
Communication-Theoretic Foundations for Optical Receivers Using Dynamically Biased Avalanche Photodiodes
<p>To meet the demands of the exponential growth in video, voice, data and mobile device traffic over the internet, the telecommunication industry has been moving toward higher speed protocols such as 40-Gb/s and 100-Gb/s. Operations at such high speeds require detectors with optimized internal …
-
Enhancing the bit error rate performance of ultra wideband systems using time-hopping pulse position modulation in multiple access environments
Ultra-Wide Band (UWB) technology is one of the possible solutions for future short-range indoor data communication with uniquely attractive features inviting major advances in wireless communications, networking, radar, imaging, and positioning systems. A major challenge when designing UWB systems …
-
Ultra-wideband technology for short-range wireless communication
… them. While ultra-wideband is being championed by several commercial companies, this technology has not followed the conventional path where commercial interest is preceded by years of academic research. This work attempts to fill in some of the gap by studying fundamental properties of …
-
Simulation, performance and interference analysis of multi-user visible light communication systems
… the characteristics of each medium. This study considers Visible Light Communications (VLC), which is expected to coexist with legacy and future radio frequency (RF) media. While most of the research on VLC has been done on optimizing the physical medium, research on higher network layers is only …
-
High Capacity VCSEL Array Based Optical Wireless Links
… of new high-speed wireless data transmission applications, such as high-definition video streaming, virtual reality, and the Internet of Things, increases the future demand for mobile data traffic capacity. However, the limited RF spectrum is not sufficient to meet this demand. Optical …
-
Digital equalization techniques for the compensation of nonlinear impairments in long-haul coherent optical communication systems
In 2008, the commercialization by Nortel of coherent optical communications digital transceivers operating at 40 Gb/s using Differential Phase Shift Keying (DPSK) revolutionized the field of fiber-optic communications because it provided superior spectral efficiency compared to the state-of-the-art …
-
Micro-transfer print integration of high-speed photodetectors to SOI platform
Photonic integrated circuits (PICs) offer a pivotal solution to meet the escalating demands of data bandwidth and used in data centres, LIDAR and optical sensing. Among various approaches, micro-transfer printing emerges as a rapid and universally compatible integration technology to generate PICs. …
-
Ultra-low power radio transceiver for wireless sensor networks
… thesis is to present the design and implementation of ultra-low power radio transceivers at microwave frequencies, which are applicable to wireless sensor network (WSN) and, in particular, to the requirement of the Speckled Computing Consortium (or SpeckNet). This was achieved through quasi-MMIC …
Page 1 of 2