Submitted by Geandra Rodrigues (geandrar@gmail.com) on 2018-04-18T18:59:28Z No. of bitstreams: 1 Leonardodemellobrandaoabdodib.pdf: 1435361 bytes, checksum: 5e9afeb4cc3aff2697cb2afe973ab9ca (MD5) / Rejected by Adriana Oliveira (adriana.oliveira@ufjf.edu.br), reason: on 2018-04-19T13:20:42Z (GMT) / Submitted by Geandra Rodrigues (geandrar@gmail.com) on 2018-04-19T13:31:11Z No. of bitstreams: 1 leonardodemellobrandaoabdodib.pdf: 1435361 bytes, checksum: 5e9afeb4cc3aff2697cb2afe973ab9ca (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2018-04-19T13:32:56Z (GMT) No. of bitstreams: 1 leonardodemellobrandaoabdodib.pdf: 1435361 bytes, checksum: 5e9afeb4cc3aff2697cb2afe973ab9ca (MD5) / Made available in DSpace on 2018-04-19T13:32:56Z (GMT). No. of bitstreams: 1 leonardodemellobrandaoabdodib.pdf: 1435361 bytes, checksum: 5e9afeb4cc3aff2697cb2afe973ab9ca (MD5) Previous issue date: 2018-02-28 / Este trabalho descreve características importantes de um sistema híbrido power line communication (PLC)/comunicação sem fio para aplicações smart grid (SG) e Internet das coisas (IoT). Além disso, discute as vantagens dos sistemas híbridos em comparação com os sistemas não híbridos. Estas vantagens são demonstradas não somente do ponto de vista técnico, mas também pela perspectiva de infraestrutura. Além disso, esta dissertação destaca uma conexão entre a capilaridade do IoT e a infraestrutura de comunicação fornecida pelo SG, bem como os aspectos de segurança que relacionam o contexto SG e IoT. Além disso, este trabalho aborda a influência do meio ambiente nas comunicações de rede elétrica e sem fio. Por outro lado, existe um enorme esforço de pesquisa em relação às tecnologias avançadas de comunicação de dados, considerando tanto as aplicações IoT de baixa taxa de bits quanto as aplicações SG, de modo a cumprir os requisitos de projeto para sistemas de telecomunicações. Com o objetivo de maximizar o uso da largura de banda disponível para aplicações PLC, esta dissertação faz uso do esquema orthogonal chirp division multiplexing (OCDM) que usa a transformada discreta de Fresnel de forma análoga à transformada discreta de Fourier. Trabalhos anteriores mostraram resultados de desempenho interessantes para esse esquema em aplicações de banda passante (por exemplo, comunicação sem fio, fibra óptica e mídia acústica subaquática). Este trabalho aborda a construção de versões do esquema OCDM que permitem a comunicação de dados usando sinais banda base, possibilitando a aplicação do esquema OCDM em sistemas PLC. Além disso, ele introduz um esquema baseado em vários usuários denominado multichirp code division multiple access (MCp-CDMA), que é uma combinação de CDMA e OCDM com o objetivo de acomodar um grande número de nós e endpoints para PLC de banda estreita e que também seja adequado para aplicações SG e IoT. Finalmente, os resultados numéricos apontam que, para um ambiente difícil e ruidoso, o esquema OCDM é capaz de suavizar o efeito do ruído impulsivo. Além disso, o esquema OCDM demonstrou resultados excepcionais quando o comprimento do canal é desconhecido comparativamente aos esquemas Hermitian symmetric orthogonal frequency division multiplexing e monoportadora com prefixo cíclico. As simulações usando o esquema MCp-CDMA demonstraram grande estabilidade e consistência de desempenho entre os diferentes cenários analisados. / This work outlines important characteristics of hybrid power line communication (PLC)/wireless data communication system for smart grid (SG) and Internet of Things (IoT) applications. Moreover, it discusses the hybrid systems advantages in comparison to non-hybrid ones. These advantages are demonstrated not only in the technical point of view but also in the infrastructural perspective. Also, this thesis highlights a connec-tion between the capillarity of IoT and the communication infrastructure provided by SG as well as the security aspects that relate SG and IoT context. Furthermore, this work addresses the environmental influence on wireless and power line communications. In another hand, there is a huge research effort regarding advanced data communication technologies considering both low bit rate IoT and SG applications in order to comply with the requirements to design telecommunications systems. Aiming to maximize the use of the available bandwidth for PLC applications, this thesis makes use of the orthog-onal chirp division multiplexing (OCDM) scheme that uses discrete Fresnel transform in an analogous fashion as discrete Fourier transform. Previous works showed interesting performance results for such scheme in passband applications (e.g., wireless, optical fiber, and underwater acoustic media). This work addresses the design of versions of the OCDM scheme that can allow the data communication using baseband signals, making possible the application of the OCDM scheme in PLC systems. Furthermore, it introduces a mul-tiuser based scheme termed multichirp code division multiple access (MCp-CDMA), which is a combination of CDMA and OCDM, in order to accommodate a large number of nodes and end-points aiming narrowband PLC that is also suitable for SG and IoT applications. Finally, numerical results point out that for a hard and noisy environment, OCDM scheme is able to soften the impulsive noise effect. Also, OCDM scheme demonstrated outstand-ing results when the channel length is unknown comparatively to Hermitian symmetric orthogonal frequency division multiplexing and single carrier-cyclic prefix schemes. The simulations using the MCp-CDMA scheme demonstrated great stability and performance consistency among the different scenarios analyzed.

International Telemetering Conference Proceedings / October 29-November 02, 1990 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Various PN codes for use in TTC spread-spectrum systems are considered. The evaluation is based on peak magnitudes and amplitude distributions of both the even and the odd autocorrelation and crosscorrelation functions. Furthermore the influence of the phase of a sequence on the correlation parameters is studied, multiple-access characteristics in terms of the total interference parameter are evaluated and synchronous as well as asynchronous code generation is considered.1

Iraq may be considered as the largest wireless market in the Gulf region. A key driving factor in the market of wireless communication, it has seen enormous growth in the mobile phone market over the last five years leading to almost 24 million subscribers in 2011. Moreover, there are several technologies and services working in Iraq; three GSM Operators, three CDMA national operators and three CDMA provinces operators. The recent growth in the mobile phone market is based on the Global System for Mobile (GSM) communications and Code Division Multiple Access (CDMA) standards creating the next-generation wireless technologies in the Iraqi Wireless Communication market. One of the essential issues of this research is to investigate the performance of the decreased Quality Of Service (QoS) caused by interferences in the services on GSM/CDMA operators in Iraq. Many issues should be studied and taken into consideration, such as; does the Multi-Coalition Forces cause the interferences, jamming, higher rate of calls drop and false ringing; or are they caused by bad design and planning? Do we need to optimise our network due to the large number of users? All these factors are investigated and the measurements of most service providers and government agencies will be gathered. A detailed analysis was included from the providers with measurements of performance and the reasons for the deterioration of wireless services. The novel contributions of this thesis is the extensive radio measurement campaign over the three mobile an CDMA operator networks and the analysis and recommendations that were drawn to suggest the best approach to improve the QoS of Wireless communication technologies. Awareness of actual reasons behind the deterioration of services will be raised to the Iraqi Government, CMC and the wireless service providers.

published_or_final_version / Electrical and Electronic Engineering / Doctoral / Doctor of Philosophy

The surest way to increase the capacity of a wireless system is by getting the transmitters and receivers closer to each other, which creates the dual bene¯ts of higher quality links and more spatial reuse. In a network with nomadic users, this inevitably involves deploying more infrastructure, typically in the form of microcells, hotspots, distributed antennas, or relays. Compared to these deployments, a less expensive alternative for cellular operators is the recent concept of femtocells { also called home base-stations { which are end consumer installed data access points in the desire to get better indoor voice and data coverage. A two-tier network consisting of a conventional macrocell overlaid with shorter range wireless hotspots o®ers poten- tial capacity bene¯ts with low upfront costs to cellular operators. This dissertation addresses the key technical challenges inherent to a femtocell-aided cellular network, speci¯cally managing radio interference and providing reliable coverage at either tier, for di®erent physical layer technologies. Speci¯c contributions include 1) an uplink capacity analysis and interference avoidance in two-tier networks employing Code Di- vision Multiple Access (CDMA), 2) a decentralized power control scheme in two-tier networks with universal frequency reuse, 3) a coverage analysis of multi-antenna two- tier networks, and 4) spectrum allocation in two-tier networks employing Orthogonal Frequency Division Multiple Access (OFDMA). The goal of this research is to inspire and motivate the use of decentralized interference management techniques requir- ing minimal network overhead in ongoing and future deployments of tiered cellular architectures. / text

Wang, Xu. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

by Wai Ho Mow. / Thesis (Ph.D.)--Chinese University of Hong Kong, 1993. / Includes bibliographical references (leaves 116-124). / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Spread Spectrum Technique --- p.2 / Chapter 1.1.1 --- Pulse Compression Radars --- p.3 / Chapter 1.1.2 --- Spread Spectrum Multiple Access Systems --- p.6 / Chapter 1.2 --- Definitions and Notations --- p.8 / Chapter 1.3 --- Organization of this Thesis --- p.12 / Chapter 2 --- Lower Bounds on Correlation of Sequences --- p.15 / Chapter 2.1 --- Welch's Lower Bounds and Sarwate's Generalization --- p.16 / Chapter 2.2 --- A New Construction and Bounds on Odd Correlation --- p.23 / Chapter 2.3 --- Known Sequence Sets Touching the Correlation Bounds --- p.26 / Chapter 2.4 --- Remarks on Other Bounds --- p.27 / Chapter 3 --- Perfect Polyphase Sequences: A Unified Approach --- p.29 / Chapter 3.1 --- Generalized Bent Functions and Perfect Polyphase Sequences --- p.30 / Chapter 3.2 --- The General Construction of Chung and Kumar --- p.32 / Chapter 3.3 --- Classification of Known Constructions ...........； --- p.34 / Chapter 3.4 --- A Unified Construction --- p.39 / Chapter 3.5 --- Desired Properties of Sequences --- p.41 / Chapter 3.6 --- Proof of the Main Theorem --- p.45 / Chapter 3.7 --- Counting the Number of Perfect Polyphase Sequences --- p.49 / Chapter 3.8 --- Results of Exhaustive Searches --- p.53 / Chapter 3.9 --- A New Conjecture and Its Implications --- p.55 / Chapter 3.10 --- Sets of Perfect Polyphase Sequences --- p.58 / Chapter 4 --- Aperiodic Autocorrelation of Generalized P3/P4 Codes --- p.61 / Chapter 4.1 --- Some Famous Polyphase Pulse Compression Codes --- p.62 / Chapter 4.2 --- Generalized P3/P4 Codes --- p.65 / Chapter 4.3 --- Asymptotic Peak-to-Side-Peak Ratio --- p.66 / Chapter 4.4 --- Lower Bounds on Peak-to-Side-Peak Ratio --- p.67 / Chapter 4.5 --- Even-Odd Transformation and Phase Alphabet --- p.70 / Chapter 5 --- Upper Bounds on Partial Exponential Sums --- p.77 / Chapter 5.1 --- Gauss-like Exponential Sums --- p.77 / Chapter 5.1.1 --- Background --- p.79 / Chapter 5.1.2 --- Symmetry of gL(m) and hL(m) --- p.80 / Chapter 5.1.3 --- Characterization on the First Quarter of gL(m) --- p.83 / Chapter 5.1.4 --- Characterization on the First Quarter of hL(m) --- p.90 / Chapter 5.1.5 --- Bounds on the Diameters of GL(m) and HL(m) --- p.94 / Chapter 5.2 --- More General Exponential Sums --- p.98 / Chapter 5.2.1 --- A Result of van der Corput --- p.99 / Chapter 6 --- McEliece's Open Problem on Minimax Aperiodic Correlation --- p.102 / Chapter 6.1 --- Statement of the Problem --- p.102 / Chapter 6.2 --- A Set of Two Sequences --- p.105 / Chapter 6.3 --- A Set of K Sequences --- p.110 / Chapter 7 --- Conclusion --- p.113 / Bibliography --- p.124

by Kin Kwong Leung. / Thesis submitted in: November 1999. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves 67-[70]). / Abstracts in English and Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Code Division Multiple Access (CDMA) --- p.1 / Chapter 1.1.1 --- The Cellular Concept --- p.2 / Chapter 1.2 --- Fading and Power Control --- p.3 / Chapter 1.2.1 --- Large Scale Fading --- p.3 / Chapter 1.2.2 --- Small Scale Fading --- p.4 / Chapter 1.2.3 --- Power Control --- p.5 / Chapter 1.2.4 --- Standard Interference Function --- p.5 / Chapter 1.3 --- Previous Work --- p.6 / Chapter 1.3.1 --- Power Control --- p.6 / Chapter 1.3.2 --- Convergence Analysis --- p.8 / Chapter 1.4 --- Scope of this Thesis --- p.8 / Chapter 1.5 --- Organization of the Thesis --- p.9 / Chapter 2 --- System Model --- p.10 / Chapter 2.1 --- System and Definitions --- p.10 / Chapter 2.2 --- Varying Link Gains Model --- p.11 / Chapter 2.3 --- SIR model in CDMA System --- p.13 / Chapter 2.4 --- Simulation Model --- p.14 / Chapter 3 --- Fade Margin --- p.17 / Chapter 3.1 --- Introduction --- p.17 / Chapter 3.2 --- Fixed-step Power Control Algorithm --- p.18 / Chapter 3.3 --- Definitions and Feasibility of SIR --- p.19 / Chapter 3.3.1 --- Definition --- p.19 / Chapter 3.3.2 --- Feasibility --- p.20 / Chapter 3.4 --- Performance Analysis on Fading Channel --- p.22 / Chapter 3.4.1 --- Single-User --- p.22 / Chapter 3.4.2 --- Multiple-User --- p.24 / Chapter 4 --- Generalized Step Power Control Algorithm --- p.28 / Chapter 4.1 --- Introduction --- p.28 / Chapter 4.2 --- Generalized Fixed Step Power Control Algorithm --- p.29 / Chapter 4.3 --- Existence of the Solution --- p.30 / Chapter 4.4 --- Parameter Optimization --- p.31 / Chapter 4.4.1 --- Single-User --- p.34 / Chapter 4.4.2 --- Multiple-User --- p.37 / Chapter 4.5 --- Performance Analysis --- p.41 / Chapter 4.5.1 --- Single-User --- p.41 / Chapter 4.5.2 --- Multiple-User --- p.42 / Chapter 4.6 --- Hybrid Scheme --- p.47 / Chapter 5 --- Convergence Analysis --- p.49 / Chapter 5.1 --- Introduction --- p.49 / Chapter 5.2 --- Totally Asynchronous Models --- p.50 / Chapter 5.3 --- Normalized Interference Function --- p.52 / Chapter 5.4 --- Existence of Quantized Solution --- p.53 / Chapter 5.5 --- Convergence Theorem --- p.55 / Chapter 6 --- Conclusion and Future Work --- p.64 / Chapter 6.1 --- Conclusion --- p.64 / Chapter 6.2 --- Future Works --- p.65 / Bibliography --- p.67

Shen Fangzhong. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 55-57). / Abstracts in English and Chinese. / Abstract --- p.i / Acknowledgements --- p.iii / List of Figures --- p.vi / List of Tables --- p.ix / Chapter Chapter 1. --- Introduction --- p.1 / Chapter 1.1. --- Motivation --- p.1 / Chapter 1.2. --- Related Work --- p.2 / Chapter 1.3. --- Our Work --- p.2 / Chapter 1.4. --- Some Assumptions --- p.2 / Chapter 1.4.1. --- Beamforming --- p.2 / Chapter 1.4.2. --- Downlink Channel --- p.2 / Chapter 1.4.3. --- Single Cell --- p.3 / Chapter 1.5. --- Thesis Road Map --- p.3 / Chapter Chapter 2. --- Preliminaries of Cell Sectoring --- p.4 / Chapter 2.1. --- Introduction --- p.4 / Chapter 2.2. --- Beamforming --- p.4 / Chapter 2.2.1. --- Linear Array --- p.5 / Chapter 2.2.2. --- Circular Array --- p.8 / Chapter 2.2.3. --- Butler Beamforming Network --- p.9 / Chapter 2.2.4. --- Dynamic Beamforming --- p.10 / Chapter 2.3. --- Power Control --- p.16 / Chapter Chapter 3. --- Dynamic Cell Sectoring --- p.19 / Chapter 3.1. --- Introduction --- p.19 / Chapter 3.2. --- Minimum Total Transmission Power sectoring --- p.21 / Chapter 3.2.1. --- Problem Statement --- p.21 / Chapter 3.2.2. --- Shortest Path Problem Formulation --- p.23 / Chapter 3.2.3. --- Shortest Path Algorithm and Complexity --- p.26 / Chapter 3.2.4. --- Graph Reduction --- p.28 / Chapter 3.2.5. --- Example --- p.30 / Chapter 3.3. --- Power Equalization Sectoring --- p.33 / Chapter 3.3.1. --- Relationship Between MinTTP Sectoring and PE Sectoring --- p.33 / Chapter 3.3.2. --- Power Equalization Sectoring Algorithm --- p.36 / Chapter 3.4. --- Numerical Results --- p.37 / Appendix --- p.44 / Chapter Chapter 4. --- Resectoring Algorithms --- p.46 / Chapter 4.1. --- Introduction --- p.46 / Chapter 4.2. --- Nyquist Sampling Theorem --- p.47 / Chapter 4.3. --- MinTTP Resectoring --- p.47 / Chapter 4.4. --- PE Resectoring --- p.43 / Chapter 4.5. --- Handoff --- p.48 / Chapter 4.5.1. --- Handoff Load --- p.49 / Chapter 4.6. --- Performance --- p.49 / Chapter Chapter 5. --- Conclusion and Future Work --- p.53 / Chapter 5.1. --- Thesis Summary --- p.53 / Chapter 5.2. --- Future Work --- p.54 / Bibliography --- p.55

Cheung Shun Keung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 80-83). / Abstracts in English and Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- The Problem --- p.1 / Chapter 1.2 --- Overview of CDMA --- p.2 / Chapter 1.3 --- Problems Encountered in Direct-Sequence (DS)CDMA --- p.3 / Chapter 1.3.1 --- Multipath Fading Scenario in DS-CDMA Cellular Mo- bile Communication --- p.3 / Chapter 1.3.2 --- Near-Far Problem --- p.4 / Chapter 1.4 --- Delimitation and Significance of the Thesis --- p.5 / Chapter 1.5 --- Summary --- p.7 / Chapter 1.6 --- Scope of the Thesis --- p.8 / Chapter 2 --- Literature Review of Blind Space-Time Processing in a wire- less CDMA Receiver --- p.9 / Chapter 2.1 --- General Background Information --- p.9 / Chapter 2.1.1 --- Time Model of K-User Chip-Synchronous CDMA --- p.9 / Chapter 2.1.2 --- Dispersive Channel Modelling --- p.10 / Chapter 2.1.3 --- Combination of K-user CDMA Time Model with the Slow Frequency-Selective Fading Channel Model to form a completed Chip-Synchronous CDMA Time Model --- p.13 / Chapter 2.1.4 --- Spatial Channel Model with Antenna Array [9] --- p.15 / Chapter 2.1.5 --- Joint Space-Time Channel Model in Chip-Synchronous CDMA --- p.19 / Chapter 2.1.6 --- Challenges to Blind Space-Time Processing in a base- station CDMA Receiver --- p.23 / Chapter 2.2 --- Literature Review of Single-User-Type Detectors used in Blind Space-Time DS-CDMA RAKE Receivers --- p.25 / Chapter 2.2.1 --- A Common Problem among the Signal Processing Schemes --- p.28 / Chapter 3 --- "Novel ""Self-Decorrelation"" Technique" --- p.29 / Chapter 3.1 --- "Problem with ""Blind"" Space-Time RAKE Processing Using Single- User-Type Detectors" --- p.29 / Chapter 3.2 --- "Review of Zoltowski & Ramos[10,11,12] Maximum-SINR Single- User-Type CDMA Blind RAKE Receiver Schemes" --- p.31 / Chapter 3.2.1 --- Space-Time Data Model --- p.31 / Chapter 3.2.2 --- The Blind Element-Space-Only (ESO) RAKE Receiver with Self-Decorrelation Pre-processing Applied --- p.32 / Chapter 3.3 --- Physical Meaning of Self-Decorrelation Pre-processing --- p.35 / Chapter 3.4 --- Simulation Results --- p.38 / Chapter 4 --- """Fractional Self-Decorrelation"" Pre-processing" --- p.45 / Chapter 4.1 --- The Blind Maximum-SINR RAKE Receivers in Chen et. al.[l] and Wong et. al.[2] --- p.45 / Chapter 4.2 --- Fractional Self-Decorrelation Pre-processing --- p.47 / Chapter 4.3 --- The Blind Element-Space-Only (ESO) RAKE Receiver with Fractional Self-Decorrelation Pre-processing Applied --- p.50 / Chapter 4.4 --- Physical Meaning of Fractional Self-Decorrelation Pre-processing --- p.54 / Chapter 4.5 --- Simulation Results --- p.55 / Chapter 5 --- Complexity Analysis and Schematics of Proposed Techniques --- p.64 / Chapter 5.1 --- Computational Complexity --- p.64 / Chapter 5.1.1 --- Self-Decorrelation Applied in Element-Space-Only (ESO) RAKE Receiver --- p.64 / Chapter 5.1.2 --- Fractional Self-Decorrelation Applied in Element-Space- Only (ESO) RAKE Receiver --- p.67 / Chapter 5.2 --- Schematics of the Two Proposed Techniques --- p.69 / Chapter 6 --- Summary and Conclusion --- p.74 / Chapter 6.1 --- Summary of the Thesis --- p.74 / Chapter 6.1.1 --- The Self-Decorrelation Pre-processing Technique --- p.75 / Chapter 6.1.2 --- The Fractional Self-Decorrelation Pre-processing Tech- nique --- p.76 / Chapter 6.2 --- Conclusion --- p.78 / Chapter 6.3 --- Future Work --- p.78 / Bibliography --- p.80 / Chapter A --- Generalized Eigenvalue Problem --- p.84 / Chapter A.1 --- Standard Eigenvalue Problem --- p.84 / Chapter A.2 --- Generalized Eigenvalue Problem --- p.84