83 research outputs found
CogRadNet: Ubiquitous heterogeneous wireless networks
Mobile radio systems have shown rapid growth and hence increase the awareness for more efficient use of spectrum. With the advancements of technology, the development of radio systems that is dynamic and efficient in
terms of spectrum usage can be realized. Cognitive radio system is one of the advancement that enhanced the adaptive capabilities of the systems that make the usage of spectrum more efficient, versatile and flexible. It also able to adapt their operations based on its internal and external factors by sensing its environment. The cognitive radio systems may be a solution for the spectrum scarcity faced by developer to tackle the issue of signal propagation and bigger coverage for broadband internet access. This paper will addressed the cognitive radio technology for ubiquitous broadband wireless internet access
Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project
Public version of the presentation given to the IASP group on the progress for annual year 2019
Narrowband IoT: from the end device to the cloud. An experimental end-to-end study
This thesis is about a novel study and experimentation of a Cloud IoT application, communicating over a NB-IoT Italian network. So far there no been presented studies, which are about the interactions between the NB-IoT network and the cloud. This thesis not only fill this gap but also shows the use of Cognitive Services to interact, through the human voice, with the IoT application. Compared with other types of mobile networks, NB-IoT is the best choice
Radio channel characterisation and system-level modelling for ultra wideband body-centric wireless communications
PhDThe next generation of wireless communication is evolving towards user-centric networks,
where constant and reliable connectivity and services are essential. Bodycentric
wireless network (BCWN) is the most exciting and emerging 4G technology
for short (1-5 m) and very short (below 1 m) range communication systems. It has
got numerous applications including healthcare, entertainment, surveillance, emergency,
sports and military. The major difference between the BCWN and conventional
wireless systems is the radio channel over which the communication takes place. The
human body is a hostile medium from the radio propagation perspective and it is
therefore important to understand and characterise the effect of the human body on
the antenna elements, the radio propagation channel parameters and hence the system
performance. In addition, fading is another concern that affects the reliability and
quality of the wireless link, which needs to be taken into account for a low cost and
reliable wireless communication system for body-centric networks.
The complex nature of the BCWN requires operating wireless devices to provide
low power requirements, less complexity, low cost and compactness in size. Apart
from these characteristics, scalable data rates and robust performance in most fading
conditions and jamming environment, even at low signal to noise ratio (SNR) is
needed. Ultra-wideband (UWB) technology is one of the most promising candidate for
BCWN as it tends to fulfill most of these requirements. The thesis focuses on the characterisation
of ultra wideband body-centric radio propagation channel using single
and multiple antenna techniques. Apart from channel characterisation, system level
modelling of potential UWB radio transceivers for body-centric wireless network is
also proposed. Channel models with respect to large scale and delay analysis are derived
from measured parameters. Results and analyses highlight the consequences
of static and dynamic environments in addition to the antenna positions on the performance
of body-centric wireless communication channels. Extensive measurement
i
campaigns are performed to analyse the significance of antenna diversity to combat
the channel fading in body-centric wireless networks. Various diversity combining
techniques are considered in this process. Measurement data are also used to predict
the performance of potential UWB systems in the body-centric wireless networks.
The study supports the significance of single and multiple antenna channel characterisation
and modelling in producing suitable wireless systems for ultra low power
body-centric wireless networks.University of Engineering and Technology Lahore Pakista
GPS system implementation using software defined radio platform
Every day new technologies are being developed and introduced to the market,
shaping people's daily life. The principal aim of our society is making up an
ecosystem that provides anything, anytime, anywhere. For this purpose, more
powerful and efficient devices, improved devices are being designed as the key
ingredients.
In this report it is shown the study and the implementation of a Global
Positioning Service device, a technology that is used by more than four thousand
millions of users. The present work explores the Global Positioning System
development using a Software Radio Defined Platform.
The implementation of this development is divided into four main parts: GPS
signal acquisition and treatment carried out by the receptor, GPS received signal
demodulation using Binary Phase Shift Keying, decoding through Direct Sequence
Spread Spectrum of the previous demodulated signal, and finally, once the necessary
data from the message was obtained, the position estimation.
In order to perform all the process it was used as working tool a device known
as Universal Software Radio Peripheral. This device allows for analysing from a
visual point of view more accurate the four different phases explained previously.
These phases represent the basis to be able to achieve the necessary knowledge
about proper operation ot the Global Positioning System. The whole application
was developd using LabVIEW software, a data
ow visual programming language
and environment designed by National Instruments.Cada dĂa nuevas tecnologĂas son desarrolladas e introducidas en el mercado,
modelando asĂ la vida diaria de la sociedad. El principal objetivo de nuestra
sociedad es conseguir crear un ecosistema que proporcione lo que sea necesario, en
cualquier momento y en cualquier lugar. Para ello, equipos más potentes, eficientes
y mejorados son diseñados como los ingredientes claves de este nuevo ecosistema.
En este trabajo se presenta el estudio y la implementaciĂłn de un receptor de
señales GPS, tecnologĂa que hoy en dĂa es utilizada por más de cuatro mil millones
de usuarios. Para ello se lleva a cabo el desarrollo del Sistema de Posicionamiento
Global (GPS) mediante la utilizaciĂłn de una plataforma de radio definida por
software.
La implementaciĂłn del desarrollo se divide en cuatro procesos principales:
adquisición y el tratamiento de la señal GPS por parte del receptor, demodulación
por desplazamiento de fase binaria (BPSK) de la señal GPS recibida, decodificación
en espectro ensanchado por secuencia directa (DSSS) de la señal demodulada y
por Ăşltimo, una vez obtenidos los datos necesarios del mensaje, la estimaciĂłn de la
posiciĂłn.
Para la realizaciĂłn de todo el proceso se utilizĂł como herramienta de trabajo
un dispositivo conocido como Universal Software Radio Peripheral (USRP). Este
aparato permite analizar desde un punto de vista visual más preciso las cuatro
fases indicadas anteriormente. Estas fases suponen la base para lograr adquirir
el conocimiento necesario sobre el funcionamiento del Sistema de Posicionamiento
Global (GPS). El desarrollo completo de la aplicaciĂłn fue implementado utilizando
LabVIEW, un entorno de desarrollo integrado diseñado por la conocida compañĂa
National Instruments.IngenierĂa en TecnologĂas de TelecomunicaciĂł
Device-to-device communications for 5G Radio Access Networks
Nowadays it is very popular to share video clips and images to one’s social network in the proximity. Direct device-to-device (D2D) communication is one of the means to respond to this requirement. D2D offers users improved end-to-end latency times, and additionally can provide higher data rates. At the same time the overall cellular network congestion decreases. D2D is also known as Proximity Services (ProSe).
LTE is missing direct D2D communication. Currently D2D for 5G is standardised in the 3rd Generation Partnership Project (3GPP) Releases 12, and in parallel Mobile and wireless communications Enablers for the Twenty-twenty Information Society (METIS) project has D2D as one of its research topics. Multiple articles have been published about D2D communication.
This thesis is a literature based thesis following D2D communication in 5G literature. The scope is to describe similarities and differences found in Technical Reports and Technical Specifications of the 3GPP Release 12, in deliverables written in METIS project and in some selected D2D related publications about D2D communications.
3GPP Release 12 concentrates on ProSe at least for public safety. ProSe communication out-of-coverage is only for public safety purposes. METIS provides multiple solutions for diverse D2D topics, for example, device discovery, radio resource management, mobility management and relaying. METIS provides solutions for D2D communication not yet mature enough for development and implementation but which might be realized in the future.Nykyisin on suosittua lähettää lyhyitä videoita tai kuvia läheisyydessä oleville ystäville. Laitteiden välinen suora kommunikointi eli D2D-viestintä tuo ratkaisun tähän vaatimukseen. D2D-viestinnän ansiosta viive lyhenee ja lisäksi siirtonopeudet kasvavat. Samaan aikaan koko verkon kuormitus vähenee.
Suora kahden laitteen välinen kommunikointi puuttuu LTE:stä. Tällä hetkellä 3GPP Release 12 standardisoi suoraa kahden laitteen välistä kommunikointia. Samanaikaisesti Mobile and wireless communications Enablers for the Twenty-twenty Information Society (METIS) –projektin yhtenä tutkimuskohteenaan on kahden laitteen välinen suora kommunikointi, Lisäksi on lukuisia julkaisuja liittyen D2D-viestintään.
Tämä diplomityö perustuu kirjallisuuteen. Sen tavoitteena on selvittää, miten kahden laitteen välistä suoraa kommunikointia on kuvattu 3GPP Release 12:ta teknisissä spesifikaatioissa, METIS-projektin julkaisuissa sekä muutamassa valitussa tieteellisessä julkaisussa. Tavoitteena on selvittää D2D-viestinnän yhtäläisyyksiä sekä poikkeamia.
3PGG Release 12 standardointi keskittyy D2D-viestinnän käyttöön ainakin julkisessa pelastustyössä. D2D-viestinnän tulee ainakin julkisessa pelastustyössä toimia myös siellä missä matkapuhelinverkko ei toimi tai sitä ei ole olemassa. METIS tarjoaa useita ratkaisuja D2D-viestinnän eri osa-alueille, esimerkiksi laitteiden tunnistamiseen, resurssien hallintaan, liikkuvuuden hallintaa ja viestien edelleen lähettämiseen. METIS-projekti on tuottanut D2D-viestinnän ratkaisuja, joiden toteuttaminen on järkevää ja mahdollista vasta tulevaisuudessa
Study and miniaturisation of antennas for ultra wideband communication systems
PhDWireless communications have been growing with an astonishing rate over the past
few years and wireless terminals for future applications are required to provide
diverse services. This rising demand prompts the needs for antennas able to cover
multiple bandwidths or an ultrawide bandwidth for various systems.
Since the release by the Federal Communications Commission (FCC) of a bandwidth
of 7.5 GHz (from 3.1 GHz to 10.6 GHz) for ultra wideband (UWB) wireless
communications, UWB has been rapidly evolving as a potential wireless technology
and UWB antennas have consequently drawn more and more attention from both
academia and industries worldwide.
Unlike traditional narrow band antennas, design and analysis of UWB antennas are
facing more challenges and difficulties. A competent UWB antenna should be
capable of operating over an ultra wide bandwidth as assigned by the FCC. At the
same time, a small and compact antenna size is highly desired, due to the integration
requirement of entire UWB systems. Another key requirement of UWB antennas is
the good time domain behaviour, i.e. a good impulse response with minimal
distortion.
This thesis focuses on UWB antenna miniaturisation and analysis. Studies have been
undertaken to cover the aspects of UWB fundamentals and antenna theory. Extensive
investigations are also conducted on three different types of miniaturised UWB
antennas.
5
The first type of miniaturised UWB antenna studied in this thesis is the loaded
orthogonal half disc monopole antenna. An inductive load is introduced to broaden
the impedance bandwidth as well as the pattern bandwidth, in other words, an
equivalent size reduction is realised.
The second type of miniaturised UWB antenna is the printed half disc monopole
antenna. By simply halving the original antenna and tuning the width of the coplanar
ground plane, a significant more than 50% size reduction is achieved.
The third type of miniaturised UWB antenna is the printed quasi-self-complementary
antenna. By exploiting a quasi-self-complementary structure and a built-in matching
section, a small and compact antenna dimension is achieved.
The performances and characteristics of the three types of miniaturised UWB
antennas are studied both numerically and experimentally and the design parameters
for achieving optimal operation of the antennas are also analysed extensively in order
to understand the antenna operations.
Also, time domain performance of the Coplanar Waveguide (CPW)-fed disc
monopole antenna is examined in this thesis to demonstrate the importance of time
domain study on UWB antennas.
Over the past few years of my PhD study, I feel honoured and lucky to work with
some of the most prestigious researchers in the Department of Electronic
Engineering, Queen Mary, University of London. I would like to show my most
cordial gratitude to those who have been helping me during the past few years. There
would be no any progress without their generous and sincere support.
First of all, I would like to thank my supervisors Professor Clive Parini and Professor
Xiaodong Chen, for their kind supervision and encouragement. I am impressed by
their notable academic background and profound understanding of the subjects,
which have proved to be immense benefits to me. It has been my great pleasure and
honour to be under their supervision and work with them.
Second of all, I would like to thank Mr John Dupuy for his help in the fabrication
and measurement of antennas I have designed during my PhD study. Also, a special
acknowledgement goes to all of the staff for all the assistance throughout my
graduate program
Recommended from our members
Defense Acquisitions: Assessments of Selected Weapon Programs
A letter report issued by the Government Accountability Office with an abstract that begins "This report is GAO's sixth annual assessment of selected weapon programs. Since 2000, the Department of Defense (DOD) has roughly doubled its planned investment in new systems from 1.6 trillion in 2007, but acquisition outcomes in terms of cost and schedule have not improved. Total acquisition costs for major defense programs in the fiscal year 2007 portfolio have increased 26 percent from first estimates, compared with 6 percent in 2000. Programs have also often failed to deliver capabilities when promised. DOD's acquisition outcomes appear increasingly suboptimal, a condition that needs to be corrected given the pressures faced by the department from other military and major nondiscretionary government demands. This report provides congressional and DOD decision makers with an independent, knowledge-based assessment of defense programs, identifying potential risks when a program's projected attainment of knowledge diverges from best practices. The programs assessed--most of which are considered major acquisitions by DOD--were selected using several factors: high dollar value, acquisition stage, and congressional interest. This report also highlights overall trends in DOD acquisition outcomes and issues raised by the cumulative experience of individual programs. GAO updates this report annually under the Comptroller General's authority to conduct evaluations on his own initiative.
- …