33 research outputs found
High Dimensional Modulation and MIMO Techniques for Access Networks
Exploration of advanced modulation formats and multiplexing techniques
for next generation optical access networks are of interest as promising
solutions for delivering multiple services to end-users. This thesis addresses
this from two different angles: high dimensionality carrierless amplitudephase
(CAP) and multiple-input multiple-output (MIMO) radio-over-fiber
(RoF) systems.
High dimensionality CAP modulation has been investigated in optical
fiber systems. In this project we conducted the first experimental demonstration
of 3 and 4 dimensional CAP with bit rates up to 10 Gb/s. These
results indicate the potentiality of supporting multiple users with converged
services. At the same time, orthogonal division multiple access
(ODMA) systems for multiple possible dimensions of CAP modulation has
been demonstrated for user and service allocation in wavelength division
multiplexing (WDM) optical access network.
2 x 2 MIMO RoF employing orthogonal frequency division multiplexing
(OFDM) with 5.6 GHz RoF signaling over all-vertical cavity surface
emitting lasers (VCSEL) WDM passive optical networks (PONs). We have
employed polarization division multiplexing (PDM) to further increase the
capacity per wavelength of the femto-cell network. Bit rate up to 1.59 Gbps
with fiber-wireless transmission over 1 m air distance is demonstrated.
The results presented in this thesis demonstrate the feasibility of high
dimensionality CAP in increasing the number of dimensions and their potentially
to be utilized for multiple service allocation to different users.
MIMO multiplexing techniques with OFDM provides the scalability in increasing
spectral effciency and bit rates for RoF systems.
High dimensional CAP and MIMO multiplexing techniques are two
promising solutions for supporting wired and hybrid wired-wireless access
networks
Recent Trends in Communication Networks
In recent years there has been many developments in communication technology. This has greatly enhanced the computing power of small handheld resource-constrained mobile devices. Different generations of communication technology have evolved. This had led to new research for communication of large volumes of data in different transmission media and the design of different communication protocols. Another direction of research concerns the secure and error-free communication between the sender and receiver despite the risk of the presence of an eavesdropper. For the communication requirement of a huge amount of multimedia streaming data, a lot of research has been carried out in the design of proper overlay networks. The book addresses new research techniques that have evolved to handle these challenges
Satellite Networks: Architectures, Applications, and Technologies
Since global satellite networks are moving to the forefront in enhancing the national and global information infrastructures due to communication satellites' unique networking characteristics, a workshop was organized to assess the progress made to date and chart the future. This workshop provided the forum to assess the current state-of-the-art, identify key issues, and highlight the emerging trends in the next-generation architectures, data protocol development, communication interoperability, and applications. Presentations on overview, state-of-the-art in research, development, deployment and applications and future trends on satellite networks are assembled
Survey of FPGA applications in the period 2000 – 2015 (Technical Report)
Romoth J, Porrmann M, Rückert U. Survey of FPGA applications in the period 2000 – 2015 (Technical Report).; 2017.Since their introduction, FPGAs can be seen in more and more different fields of applications. The key advantage is the combination of software-like flexibility with the performance otherwise common to hardware. Nevertheless, every application field introduces special requirements to the used computational architecture. This paper provides an overview of the different topics FPGAs have been used for in the last 15 years of research and why they have been chosen over other processing units like e.g. CPUs
SIMULINK Implementation of a CDMA Transmitter
An implementation of a Code Division Multiple Access (CDMA) transmitter has been developed using SIMULINK and MATLAB. This transmitter uses a modified carrier in modulation. This modified carrier, which is frequency modulated, has been shown to reduce intersymbol interference (ISI) and multiple access interference (MAl). These two types of interference are caused by multipath propagation which results in delayed versions of the original signal. The benefits of this modified modulation technique are apparent when there are delays involved. The spreading sequences used are 7- bit Gold codes which allow a maximum of nine users. The initial trials of the transmitter indicate that it is functioning correctly
Radar Technology
In this book “Radar Technology”, the chapters are divided into four main topic areas: Topic area 1: “Radar Systems” consists of chapters which treat whole radar systems, environment and target functional chain. Topic area 2: “Radar Applications” shows various applications of radar systems, including meteorological radars, ground penetrating radars and glaciology. Topic area 3: “Radar Functional Chain and Signal Processing” describes several aspects of the radar signal processing. From parameter extraction, target detection over tracking and classification technologies. Topic area 4: “Radar Subsystems and Components” consists of design technology of radar subsystem components like antenna design or waveform design
OBSAI interoperability in multi-vendor WiMAX base station architecture
Wireless networks have become a necessity with the increased mobility in human life. From cellular telephony to the Internet, all types of communication are now provided over wireless networks. However, to offer wireless network coverage over an area requires a potentially expensive infrastructure deployment. Such deployment requires base stations which until now have been completely proprietary to the equipment vendors. Moreover, proprietary equipment is almost always costly and offer less flexibility than standardized modular solutions. This situation results in a high cost for network upgradation and hinders network development. A remedy is available via modularization, hence the Open Base Station Architecture Initiative (OBSAI) is trying to modularize and standardize one of the most expensive elements of the wireless infrastructure, the base station. OBSAI standards aim to modularize the base station architecture and enable true interoperability among the various modules.
However, the goal has not yet been achieved due to some features of the standard. This thesis project has studied the standards and pointed out some areas that must be concentrated upon when performing interoperability tests. It also proposes several standards amendments to foster greater interoperability among the modules of a base station. This study focuses on the RP3 interface of the OBSAI specification with the goal of making truly inter-operable baseband and RF modules, thus commoditizing the modules. The result is expected to be lower cost, greater interoperability, faster time-to-market, and more cooperative research