BER Performance Simulation of Generalized MC DS-CDMA System with Time-Limited Blackman Chip Waveform

Multiple access interference encountered in multicarrier direct sequence-code division multiple access (MC DS-CDMA) is the most important difficulty that depends mainly on the correlation properties of the spreading sequences as well as the shape of the chip waveforms employed. In this paper, bit error rate (BER) performance of the generalized MC DS-CDMA system that employs time-limited Blackman chip waveform is presented for Nakagami-m fading channels. Simulation results show that the use of Blackman chip waveform can improve the BER performance of the generalized MC DS-CDMA system, as compared to the performances achieved by using timelimited chip waveforms in the literature

Proceedings of the Fifth International Mobile Satellite Conference 1997

Satellite-based mobile communications systems provide voice and data communications to users over a vast geographic area. The users may communicate via mobile or hand-held terminals, which may also provide access to terrestrial communications services. While previous International Mobile Satellite Conferences have concentrated on technical advances and the increasing worldwide commercial activities, this conference focuses on the next generation of mobile satellite services. The approximately 80 papers included here cover sessions in the following areas: networking and protocols; code division multiple access technologies; demand, economics and technology issues; current and planned systems; propagation; terminal technology; modulation and coding advances; spacecraft technology; advanced systems; and applications and experiments

Proceedings of the Second International Mobile Satellite Conference (IMSC 1990)

Presented here are the proceedings of the Second International Mobile Satellite Conference (IMSC), held June 17-20, 1990 in Ottawa, Canada. Topics covered include future mobile satellite communications concepts, aeronautical applications, modulation and coding, propagation and experimental systems, mobile terminal equipment, network architecture and control, regulatory and policy considerations, vehicle antennas, and speech compression

Proceedings of the Third International Mobile Satellite Conference (IMSC 1993)

Satellite-based mobile communications systems provide voice and data communications to users over a vast geographic area. The users may communicate via mobile or hand-held terminals, which may also provide access to terrestrial cellular communications services. While the first and second International Mobile Satellite Conferences (IMSC) mostly concentrated on technical advances, this Third IMSC also focuses on the increasing worldwide commercial activities in Mobile Satellite Services. Because of the large service areas provided by such systems, it is important to consider political and regulatory issues in addition to technical and user requirements issues. Topics covered include: the direct broadcast of audio programming from satellites; spacecraft technology; regulatory and policy considerations; advanced system concepts and analysis; propagation; and user requirements and applications

Dynamic Capacity Enhancement using a Smart Antenna in Mobile Telecommunications Networks

This work describes an investigation into the performance of antennas for mobile base station applications and techniques for improving the coverage and capacity within a base station cell. The work starts by tracing the development of mobile systems, both in technical and commercial terms, from the earliest analogue systems to present day broadband systems and includes anticipated future developments. This is followed by an outline of how smart antenna systems can be utilised to improve cell coverage and capacity. A novel smart antenna system incorporating an array of slant ± 450 dual- polarised stacked patch elements four columns wide excited by a novel multi-beam forming and beam shaping network has been designed, simulated and implemented. It is found that for an ideal smart antenna array, four narrow overlapping beams, one wide “broadcast channel” beam and right and left shaped beams can be provided. Results are presented for the simulation of the smart antenna system using CST EM simulation software which inherently includes mutual coupling and the effects of a truncated ground plane on the element patterns. The results show some significant changes to the desired set of coverage patterns and various mutual coupling compensation techniques have been reviewed. An improved design technique has been developed for compensating the performance degrading effects of mutual coupling and finite ground plane dimensions in microstrip antenna arrays. The improved technique utilises combination of two previously known techniques: complex excitation weights compensation by inversion of the array mutual coupling scattering matrix and the incorporation of a WAIM (wide angle impedance matching) sheet. The technique has been applied to a novel multi-beam smart antenna array to demonstrate the efficacy of the technique by electromagnetic simulation. In addition, a demonstrator array has been constructed and tested which has yielded a positive conformation of the simulation results. For the developed demonstrator array which provides seven different beams, beams “footprints” have been predicted both for free space propagation and for urban propagation to evaluate the dynamic capacity performance of the smart antenna in a 3G mobile network. The results indicate that sector capacity can be dynamically tailored to user demand profiles by selection of the appropriate beam patterns provided by the novel smart antenna system

Performance evaluation of a 40 GHz broadband cellular system

Doutoramento em Engenharia ElectrónicaO trabalho apresentado nesta tese enquadra-se na área das comunicações móveis celulares e tem subjacente a utilização de um protótipo de um sistema de comunicações móveis de banda larga desenvolvido no âmbito do projecto Europeu SAMBA. Este protótipo apresenta como principais características inovadoras as taxas de transmissão, a frequência de operação, a mobilidade e os protocolos de handover rádio. Inicialmente são descritos aspectos relacionados com a evolução das comunicações móveis ao longo do tempo e apresentados conceitos teóricos fundamentais para compreender o comportamento do canal rádio móvel e os mecanismos de propagação. São identificados os tipos de desvanecimento e descritos os vários parâmetros que permitem caracterizar o canal rádio. A descrição do impacto do desvanecimento e as formas de o mitigar são apresentadas para contextualizar o trabalho desenvolvido em termos da especificação do protótipo e as opções escolhidas. As características globais do protótipo são apresentadas o que inclui a descrição do interface rádio, da arquitectura, dos módulos de RF, dos módulos de processamento de banda base, protocolos e algoritmo de transferência rádio. O protótipo foi avaliado em vários cenários com diferentes características. No cenário exterior foi analisada uma rua urbana típica do tipo canyon. Em termos de configuração do sistema foram consideradas e analisadas várias alturas da Estação Base, anglos de inclinação das antenas, várias velocidades da Terminal Móvel, operação com e sem linha de vista e a penetração do sinal rádio em ruas transversais. No cenário interior foram realizados testes similares e medidas relativas às transferências que só foram executadas para este cenário por questões logísticas. Numa primeira abordagem foi analisada a cobertura oferecida por cada célula e posteriormente activada a funcionalidade de transferência. Foram também efectuados estudos com uma única Estação Base cobrindo toda a área. Em termos de caracterização do canal rádio em banda larga são apresentadas medidas da resposta impulsiva para dois cenários interiores e complementados por outros estudos via simulação utilizando uma ferramenta de ray tracing. Nas medidas foi utilizado um método de medição do canal no domínio da frequência. A relação entre o Espalhamento do Atraso e a Banda de Coerência em diferentes cenários foi analisada em detalhe e feita a verificação em termos da violação do limite teórico de Fleury. Como consequência dos tópicos abordados, esta tese apresenta um estudo abrangente de aspectos relacionados com o comportamento do canal rádio na faixa dos 40 GHz e a análise das opções técnicas do protótipo em termos do seu desempenho no âmbito dos sistemas de comunicações móveis 4G.The work presented in this thesis addresses the area of mobile cellular broadband communications and encompasses the utilization of a prototype developed in the framework of the European project SAMBA. This prototype has as main innovative characteristics the transmission rates, the frequency band of operation, the mobility and the radio handover protocols. Initially are described aspects related with the historical evolution of the mobile communications and presented fundamental theoretical concepts to understand the behaviour of the radio channel and the propagation mechanisms. The different types of fading are identified as well as the various parameters that allow the characterisation of the radio channel. The fading impact and its mitigation techniques are presented to contextualise the work developed in terms of the specification of the features implemented in the prototype and the options available. The global characteristic of the prototype are presented namely the radio interface, the architecture, the RF modules, the baseband modules, protocols and the algorithm for the radio handover. The prototype was evaluated in various scenarios with different characteristics. In the outdoor scenario a canyon type street was analysed. Several heights of the Base Station, antenna tilting angles, Mobile Terminal velocities, operation in line-of-sight and non line-of-sight and the penetration of the signal in a transversal street. In the indoor scenario similar measurements were performed. The handover feature was analysed just for this scenario due to logistic reasons. In a first phase the coverage provided by each Base Station was analysed and subsequently activated the handover functionality. Studies using a single Base Station to cover the whole pavilion were also performed. In terms of broadband analysis, channel impulse response measurements were performed using a frequency domain technique in two scenarios and complemented by others analysed only using a ray tracing simulation tool. The relationship between the radio channel Delay Spread and the Coherence Bandwidth was analysed in different scenarios and the possible violation of the Fleury lower bond checked. As a consequence of the several topics covered in this thesis, a deep study of the aspects related with the behaviour of the radio channel in the 40 GHz band and the performance of the technical options implemented in the prototype is presented in the framework of 4G mobile communication systems

Proceedings of the 19th NASA Propagation Experimenters Meeting (NAPEX 19) and the 7th Advanced Communications Technology Satellite (ACTS) Propagation Studies Workshop (APSW 7)

The NASA Propagation Experimenters Meeting (NAPEX), supported by the NASA Propagation Program, is convened annually to discuss studies made on radio wave propagation by investigators from domestic and international organizations. NAPEX 19 was held on 14 Jun. 1995, in Fort Collins, Colorado. Participants included representatives from Canada, Japan, and the United States, including researchers from universities, government agencies, and private industry. The meeting focused on mobile personal satellite systems and the use of 20/30-GHz band for fixed and mobile satellite applications. In total, 18 technical papers were presented. Following NAPEX 19, the Advanced Communications Technology Satellite (ACTS) Propagation Studies Workshop 7 (APSW 7) was held on 15-16 Jun. 1995, to review ACTS propagation activities with emphasis on the experimenters' status reports and dissemination of propagation data to industry

Dynamic capacity enhancement using a smart antenna in mobile telecommunications networks

This work describes an investigation into the performance of antennas for mobile base station applications and techniques for improving the coverage and capacity within a base station cell. The work starts by tracing the development of mobile systems, both in technical and commercial terms, from the earliest analogue systems to present day broadband systems and includes anticipated future developments. This is followed by an outline of how smart antenna systems can be utilised to improve cell coverage and capacity. A novel smart antenna system incorporating an array of slant ± 450 dual- polarised stacked patch elements four columns wide excited by a novel multi-beam forming and beam shaping network has been designed, simulated and implemented. It is found that for an ideal smart antenna array, four narrow overlapping beams, one wide “broadcast channel” beam and right and left shaped beams can be provided. Results are presented for the simulation of the smart antenna system using CST EM simulation software which inherently includes mutual coupling and the effects of a truncated ground plane on the element patterns. The results show some significant changes to the desired set of coverage patterns and various mutual coupling compensation techniques have been reviewed. An improved design technique has been developed for compensating the performance degrading effects of mutual coupling and finite ground plane dimensions in microstrip antenna arrays. The improved technique utilises combination of two previously known techniques: complex excitation weights compensation by inversion of the array mutual coupling scattering matrix and the incorporation of a WAIM (wide angle impedance matching) sheet. The technique has been applied to a novel multi-beam smart antenna array to demonstrate the efficacy of the technique by electromagnetic simulation. In addition, a demonstrator array has been constructed and tested which has yielded a positive conformation of the simulation results. For the developed demonstrator array which provides seven different beams, beams “footprints” have been predicted both for free space propagation and for urban propagation to evaluate the dynamic capacity performance of the smart antenna in a 3G mobile network. The results indicate that sector capacity can be dynamically tailored to user demand profiles by selection of the appropriate beam patterns provided by the novel smart antenna system.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Cooperative Radio Communications for Green Smart Environments

The demand for mobile connectivity is continuously increasing, and by 2020 Mobile and Wireless Communications will serve not only very dense populations of mobile phones and nomadic computers, but also the expected multiplicity of devices and sensors located in machines, vehicles, health systems and city infrastructures. Future Mobile Networks are then faced with many new scenarios and use cases, which will load the networks with different data traffic patterns, in new or shared spectrum bands, creating new specific requirements. This book addresses both the techniques to model, analyse and optimise the radio links and transmission systems in such scenarios, together with the most advanced radio access, resource management and mobile networking technologies. This text summarises the work performed by more than 500 researchers from more than 120 institutions in Europe, America and Asia, from both academia and industries, within the framework of the COST IC1004 Action on "Cooperative Radio Communications for Green and Smart Environments". The book will have appeal to graduates and researchers in the Radio Communications area, and also to engineers working in the Wireless industry. Topics discussed in this book include: • Radio waves propagation phenomena in diverse urban, indoor, vehicular and body environments• Measurements, characterization, and modelling of radio channels beyond 4G networks• Key issues in Vehicle (V2X) communication• Wireless Body Area Networks, including specific Radio Channel Models for WBANs• Energy efficiency and resource management enhancements in Radio Access Networks• Definitions and models for the virtualised and cloud RAN architectures• Advances on feasible indoor localization and tracking techniques• Recent findings and innovations in antenna systems for communications• Physical Layer Network Coding for next generation wireless systems• Methods and techniques for MIMO Over the Air (OTA) testin