6 research outputs found

    Quantum Dash Multi-Wavelength Lasers for Next Generation High Capacity Multi-Gb/s Millimeter-Wave Radio-over-Fiber Wireless Communication Networks

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    The ever-increasing proliferation of mobile users and new technologies with different applications and features, and the demand for reliable high-speed high capacity, pervasive connectivity and low latency have initiated a roadmap for the next generation wireless networks, fifth generation (5G), which is set to revolutionize the existing wireless communications. 5G will use heterogeneous higher carrier frequencies from the plentifully available spectra in the higher microwave and millimeter-wave (MMW) bands, including licensed and unlicensed spectra, for achieving multi-Gb/s wireless connectivity and overcoming the existing wireless spectrum crunch in the sub-6 GHz bands, resulting from the tremendous growth of data-intensive technologies and applications. The use of MMW when complemented by multiple-input-multiple-output (MIMO) technology can significantly increase data capacity through spatial multiplexing, and improve coverage and system reliability through spatial diversity. However, high-frequency MMW signals are prone to extreme propagation path loss and are challenging to generate and process with conventional bandwidth-limiting electronics. In addition, the existing digitized fronthaul for centralized radio access network (C-RAN) architecture is considered inefficient for 5G and beyond. Thus, to fully exploit the promising MMW 5G new radio (NR) resource and to alleviate the electronics and fronthaul bottleneck, microwave photonics with analog radio-over-fiber (A-RoF) technology becomes instrumental for optically synthesizing and processing broadband RF MMW wireless signals over optical links. The generation and distribution of high-frequency MMW signals in the optical domain over A-RoF links facilitate the seamless integration of high-capacity, reliable and transparent optical networks with flexible, mobile and pervasive wireless networks, extending the reach and coverage of high-speed broadband MMW wireless communications. Consequently, this fiber-wireless integration not only overcomes the problem of high bandwidth requirements, transmission capacity and span limitation but also significantly reduces system complexity considering the deployment of ultra-dense small cells with large numbers of 5G remote radio units (RRUs) having massive MIMO antennas with beamforming capabilities connected to the baseband units (BBU) in a C-RAN environment through an optical fiber-based fronthaul network. Nevertheless, photonic generation of spectrally pure RF MMW signals either involves complex circuitry or suffers from frequency fluctuation and phase noise due to uncorrelated optical sources, which can degrade system performance. Thus simple highly integrated and cost-efficient low-noise optical sources are required for next-generation MMW RoF wireless transmission systems. More recently, well-designed quantum confined nanostructures such as semiconductor quantum dash/dot multi-wavelength lasers (QD-MWLs) have attracted more interest in the photonic generation of RF MMW signals due to their simple compact and integrated design with highly coherent and correlated optical signals having a very low phase and intensity noise attributed to the inherent properties of QD materials. The main theme of this thesis revolves around the experimental investigation of such nanostructures on the device and system level for applications in high-speed high-capacity broadband MMW RoF-based fronthaul and wireless access networks. Several photonic-aided high-capacity long-reach MMW RoF wireless transmission systems are proposed and experimentally demonstrated based on QD-MWLs with the remote distribution and photonic generation of broadband multi-Gb/s MMW wireless signals at 5G NR (FR2) in the K-band, Ka-band and V-band in simplex, full-duplex and MIMO configurations over 10 to 50 km optical fiber and subsequent wireless transmission and detection. The QD-MWLs-based photonic MMW RoF wireless transmission systems’ designs and experimental demonstrations could usher in a new era of ultra-high-speed broadband multi-Gb/s wireless communications at the MMW frequency bands for next-generation wireless networks. The QD-MWLs investigated in this thesis include a simple monolithically integrated and highly coherent low-noise single-section semiconductor InAs/InP QD buried heterostructure passively mode-locked (PML) laser-based optical coherent frequency comb (CFC) and a novel monolithic highly correlated low-noise semiconductor InAs/InP buried heterostructure common-cavity QD dual-wavelength distributed feedback laser (QD-DW-DFBL). The performance of each device is thoroughly characterized experimentally in terms of optical phase noise, relative intensity noise (RIN), timing jitter and RF phase noise exhibiting promising results. Based on these devices, different long-reach photonic MMW RoF wireless transmission systems, including simplex single-input-single-output (SISO) and multiple-input-multiple-output (MIMO) and bidirectional configurations, are proposed and experimentally demonstrated with real-time remote electrical RF synthesizer-free all-optical frequency up-conversion, wireless transmission and successful reception of wide-bandwidth multi-level quadrature amplitude modulated (M-QAM) RF MMW wireless signals having bit rates ranging from 4 Gb/s to 36 Gb/s over different hybrid fiber-wireless links comprising of standard single mode fiber (SSMF) and indoor wireless channel. The end-to-end links are thoroughly investigated in terms of error-vector-magnitude (EVM), bit-error-rat (BER), constellations and eye diagrams, realizing successful error-free transmission. Finally, novel high-capacity spectrally efficient MIMO and optical beamforming enabled photonic MMW RoF wireless transceivers design and methods based on QD-MWLs with wavelength division multiplexing (WDM) and space division multiplexing (SDM) are proposed and discussed. A proof-of-concept implementation of the proposed photonic MMW RoF wireless transmission system is also simulated in a simple WDM-based configuration with bidirectional 4×4 MIMO MMW carrier streams

    You Can\u27t Get There from Here: Movement SF and the Picaresque

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    This dissertation examines the crisis of authenticity in postmodern culture and argues that contemporary science fiction, specifically the subgenre of Movement SF, has evolved a unique answer to this crisis by adopting, perhaps spontaneously, the picaresque narrative structure. Postmodern fiction has a tenuous relationship with the issue of authenticity, such that the average postmodern subject is utterly without true authenticity at all, alternately victim to the socioeconomic conditions of his or her culture and to the elision of the self as a result of the homogenizing effects of advertising, television, etc. Postmodern SF also carries this bleak perception of the possibility of agency; William Gibson\u27s Sprawl and Bridge trilogies are rife with negations of human agency at the metaphorical hands of various aspects and incarnations of what Fredric Jameson terms the technological sublime. This dissertation puts forth the argument that a group of post-Eighties SF texts all participate in a spontaneous revival of the picaresque mode, using the picaresque journey and related motifs to re-authenticate subjects whose identity and agency are being erased by powerful social and economic forces exterior to and normally imperceptible by the individual. This dissertation is organized around three loosely connected parts. Part 1 attempts to define Movement SF by separating the various, often confusing marketing labels (such as cyberpunk, postcyberpunk, etc.) and extracting a cluster of core characteristics that have shaped the genre since its inception in the early 80s. Part 1 further examines how these core characteristics (or premises) of Movement SF provide fertile ground for picaresque narrative strategies. Part 2 describes in detail the picaresque as it appears in Movement SF, examining worldbuilding strategies, the persistence and evolution of tropes and motifs common to the traditional picaresque, and the generation of new tropes and motifs unique to Movement picaresques. Part 3 examines the spatial tactics used in Movement picaresque narratives to enable picaresque marginality in totalized, globalized environments. Furthermore, Part 3 examines the use of psychological plurality as an internal tactic to escape closed environments

    A history and interpretive analysis of play for today, (BBC1, 1970-84)

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    My thesis is a history and interpretive analysis of Play for Today (BBC1, 1970-84) (PfT). It is important, as this prestigious strand of one-off dramas has yet to receive any in-depth longitudinal studies. I have used a mix of qualitative and quantitative analysis: informed by my having watched or read Camera Scripts for over four-fifths of PfT. I have used archival sources from the BBC Written Archives Centre and digital archives, alongside selected oral history testimony regarding PfT from its practitioners. PfT has been valued as emblematic of a TV ‘Golden Age’, and an equally lost era of cultural democratisation in Britain. It made artful uses of video and film aesthetics, harnessing both to create vivid, human-centric one-off dramas that were generally highly valued by critics and audiences for their toughness and variety. PfT represented London and Northern Ireland frequently, and also Scotland and Northern England more from 1974. However, PfT generally neglected Wales and the North East of England. Its representations of non-metropolitan Britain were variously downbeat and upbeat, reflecting deep unease at, or approval of, aspects of contemporaneous social change. PfT represented working-class men especially richly in the mid-1970s, when it was also often male-centric, but it included significantly more women writers from 1977-82. In its later years, PfT built on its earlier deep insights into masculine workspaces to include varied feminist dramas, which critiqued male violence. While it had relatively few Black or Asian creators, its many gay dramatists and anarchistic Jewish playwrights contributed to its humanist range. PfTs like In the Beautiful Caribbean and Even Solomon were more representationally advanced than BBC-TV’s discussion programmes. My findings reveal an original history and interpretive analysis of PfT, in its many varied contexts. They are of considerable interest to TV historians and also TV drama practitioners today

    A Holmes and Doyle Bibliography, Volume 5: Periodical Articles--Secondary References, Alphabetical Listing

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    This bibliography is a work in progress. It attempts to update Ronald B. De Waal’s comprehensive bibliography, The Universal Sherlock Holmes, but does not claim to be exhaustive in content. New works are continually discovered and added to this bibliography. Readers and researchers are invited to suggest additional content. Volume 5 includes "passing" or "secondary" references, i.e. those entries that are passing in nature or contain very brief information or content

    A Holmes and Doyle Bibliography, Volume 6: Periodical Articles, Subject Listing, By De Waal Category

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    This bibliography is a work in progress. It attempts to update Ronald B. De Waal’s comprehensive bibliography, The Universal Sherlock Holmes, but does not claim to be exhaustive in content. New works are continually discovered and added to this bibliography. Readers and researchers are invited to suggest additional content. Volume 6 presents the periodical literature arranged by subject categories (as originally devised for the De Waal bibliography and slightly modified here)

    A Holmes and Doyle Bibliography, Volume 9: All Formats—Combined Alphabetical Listing

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    This bibliography is a work in progress. It attempts to update Ronald B. De Waal’s comprehensive bibliography, The Universal Sherlock Holmes, but does not claim to be exhaustive in content. New works are continually discovered and added to this bibliography. Readers and researchers are invited to suggest additional content. This volume contains all listings in all formats, arranged alphabetically by author or main entry. In other words, it combines the listings from Volume 1 (Monograph and Serial Titles), Volume 3 (Periodical Articles), and Volume 7 (Audio/Visual Materials) into a comprehensive bibliography. (There may be additional materials included in this list, e.g. duplicate items and items not yet fully edited.) As in the other volumes, coverage of this material begins around 1994, the final year covered by De Waal's bibliography, but may not yet be totally up-to-date (given the ongoing nature of this bibliography). It is hoped that other titles will be added at a later date. At present, this bibliography includes 12,594 items
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