Interference in Large Wireless Networks

Interference in Large Wireless Networks
Author: Martin Haenggi
Publisher: Now Publishers Inc
Total Pages: 136
Release: 2009
Genre: Wireless communication systems
ISBN: 1601982984

Since interference is the main performance-limiting factor in most wireless networks, it is crucial to characterize the interference statistics. The main two determinants of the interference are the network geometry (spatial distribution of concurrently transmitting nodes) and the path loss law (signal attenuation with distance). For certain classes of node distributions, most notably Poisson point processes, and attenuation laws, closed-form results are available, for both the interference itself as well as the signal-to-interference ratios, which determine the network performance. This monograph presents an overview of these results and gives an introduction to the analytical techniques used in their derivation. The node distribution models range from lattices to homogeneous and clustered Poisson models to general motion-invariant ones. The analysis of the more general models requires the use of Palm theory, in particular conditional probability generating functionals, which are briefly introduced in the appendix.

Communications in Interference Limited Networks

Communications in Interference Limited Networks
Author: Wolfgang Utschick
Publisher: Springer
Total Pages: 519
Release: 2016-02-04
Genre: Technology & Engineering
ISBN: 3319224409

This book offers means to handle interference as a central problem of operating wireless networks. It investigates centralized and decentralized methods to avoid and handle interference as well as approaches that resolve interference constructively. The latter type of approach tries to solve the joint detection and estimation problem of several data streams that share a common medium. In fact, an exciting insight into the operation of networks is that it may be beneficial, in terms of an overall throughput, to actively create and manage interference. Thus, when handled properly, "mixing" of data in networks becomes a useful tool of operation rather than the nuisance as which it has been treated traditionally. With the development of mobile, robust, ubiquitous, reliable and instantaneous communication being a driving and enabling factor of an information centric economy, the understanding, mitigation and exploitation of interference in networks must be seen as a centrally important task.

Fading and Interference Mitigation in Wireless Communications

Fading and Interference Mitigation in Wireless Communications
Author: Stefan Panic
Publisher: CRC Press
Total Pages: 263
Release: 2013-12-11
Genre: Computers
ISBN: 1466508426

Fading and Interference Mitigation in Wireless Communications will help readers stay up to date with recent developments in the performance analysis of space diversity reception over fading channels in the presence of cochannel interference. It presents a unified method for computing the performance of digital communication systems characterized by a variety of modulation and detection types and channel models. The book includes coverage of multichannel reception in various fading environments, influence of cochannel interference, and macrodiversity reception when channels are simultaneously affected by various types of fading and shadowing.

Coping with Interference in Wireless Networks

Coping with Interference in Wireless Networks
Author: Seyed Javad Kazemitabar
Publisher: Springer Science & Business Media
Total Pages: 109
Release: 2010-11-22
Genre: Technology & Engineering
ISBN: 9048199905

Unlike wired networks where transmitters have no effect on receivers other than their own, in wireless networks we are limited by interference. The traditional routing methods are not optimal any more when it comes to a wireless medium. The maximum data rate on each link depends not only on the power in that link but also on the transmitted power from adjacent links. That is why the problem of power optimal routing needs to be solved jointly with scheduling. This suggests a cross layer design method as opposed to traditional networking where the algorithm for each layer is designed separately. In Coping with Interference in Wireless Networks we introduce several methods engaging different layers of network to mitigate interference in a wireless network.

Fundamentals of Wireless Communication

Fundamentals of Wireless Communication
Author: David Tse
Publisher: Cambridge University Press
Total Pages: 598
Release: 2005-05-26
Genre: Computers
ISBN: 9780521845274

This textbook takes a unified view of the fundamentals of wireless communication and explains cutting-edge concepts in a simple and intuitive way. An abundant supply of exercises make it ideal for graduate courses in electrical and computer engineering and it will also be of great interest to practising engineers.

Enhancing Multi-User Wireless Networks with Pattern Reconfigurable Antennas

Enhancing Multi-User Wireless Networks with Pattern Reconfigurable Antennas
Author: Simon Begashaw
Publisher:
Total Pages: 143
Release: 2019
Genre: Antennas (Electronics)
ISBN:

The explosive demand for high data rates and the need ubiquitous wireless connectivity has led to the phenomenon of network densification, the deployment of large number of base station within a geographic area. Since the radio spectrum is limited, wireless transmissions need to share a common resource which results in interference. Interference in turn creates a bottleneck on the communication rate. Recently three breakthroughs have been made to increase the capacity of wireless networks while mitigating interference : multiple input multiple output (MIMO) beamforming, interference alignment (IA) and pattern reconfigurable antennas (PRA). While a great deal of progress has been made on understanding each individually, relatively little is known about how to use these techniques in combination to increase system performance. In this dissertation, we analyze and experimentally evaluate how these new technologies can be leveraged to enhance the rate performance of communication networks. Specifically, we address three problems: i) enhancing multi-user MIMO performance with PRA, ii) improving IA performance with PRA-based antenna selection, and iii) enabling practical blind IA with PRA. To understand the impact PRAs on MU-MIMO and IA, it is necessary to evaluate their performance through measurements. Simulation-based studies often reiterate over set of simplistic channel models and unrealistic assumptions. This dissertation focuses on a measurement-based evaluation approach. For each of these problems, a hardware testbed implementation and measurement methodology is developed for evaluating the performance of the aforementioned technologies through efficient and repeatable experiments. The first two major contributions of this dissertation focus on multi-user MIMO (MU-MIMO) and IA. While the theoretical rate gains of MU-MIMO and IA are substantial, the performance gains in practical systems and measured channels have been limited. One of the key limiting factors are spatially correlated user channels. In this work, we propose MU-MIMO and IA transmission schemes that leverage the pattern diversity provided by PRAs to mitigate the effects of spatial correlation in wireless channels. PRAs are capable of dynamically adjusting their radiation pattern, providing an additional degree of freedom that can be exploited to improve MU-MIMO and IA performance by treating the array configuration and radiation characteristics as additional components in the joint optimization of adaptive system parameters. We quantify the benefits of pattern diversity on the rate performance of MU-MIMO and IA systems through extensive measurements. Furthermore, we develop efficient antenna mode selection algorithms to realize those benefits without increasing the system complexity or overhead, making these techniques suitable for practical implementation. The third contribution of this dissertation focuses on a transmission technique known as blind IA. In contrast to MU-MIMO and conventional IA, blind IA is signaling scheme that suppresses interference in multi-user systems, without the knowledge of channel state information at the transmitter (CSIT). The key to performing IA without CSIT is the use of PRAs that are capable of dynamically switching among a fixed number of radiation patterns to introduce artificial fluctuations in the channel. In this dissertation, we develop a novel implementation of a blind IA system on a software defined radio platform where each of the receivers is equipped with a PRA. Our work provides the first experimental evaluation of PRA-based blind IA schemes and demonstrates significant gains in rate and reliability over traditional orthogonal transmission schemes such as TDMA.

Adaptive Signal Processing in Wireless Communications

Adaptive Signal Processing in Wireless Communications
Author: Mohamed Ibnkahla
Publisher: CRC Press
Total Pages: 520
Release: 2017-12-19
Genre: Technology & Engineering
ISBN: 1420046020

Adaptive techniques play a key role in modern wireless communication systems. The concept of adaptation is emphasized in the Adaptation in Wireless Communications Series through a unified framework across all layers of the wireless protocol stack ranging from the physical layer to the application layer, and from cellular systems to next-generation wireless networks. This specific volume, Adaptive Signal Processing in Wireless Communications is devoted to adaptation in the physical layer. It gives an in-depth survey of adaptive signal processing techniques used in current and future generations of wireless communication systems. Featuring the work of leading international experts, it covers adaptive channel modeling, identification and equalization, adaptive modulation and coding, adaptive multiple-input-multiple-output (MIMO) systems, and cooperative diversity. It also addresses other important aspects of adaptation in wireless communications such as hardware implementation, reconfigurable processing, and cognitive radio. A second volume in the series, Adaptation and Cross-layer Design in Wireless Networks(cat no.46039) is devoted to adaptation in the data link, network, and application layers.

Fading and Shadowing in Wireless Systems

Fading and Shadowing in Wireless Systems
Author: P. Mohana Shankar
Publisher: Springer Science & Business Media
Total Pages: 477
Release: 2011-12-07
Genre: Technology & Engineering
ISBN: 1461403677

The study of signal transmission and deterioration in signal characteristics as the signal propagates through wireless channels is of great significance. The book presents a comprehensive view of channel degradation arising from fading and shadowing. Various statistical models including simple, hybrid, compound, complex and cascaded ones are presented with detailed derivations along with measures to quantify the deterioration such as the amount of fading, error rates and outage probabilities. The models range from the Rayleigh and Rician through Suzuki, generalized K, cascaded and alpha-mu and similar ones. This is followed by the analysis of mitigation of fading and shadowing through diversity (simple, hybrid, micro- and macro- level) and combining algorithms. The density and distribution functions, error rates and outages are derived and results analyzed to quantify the improvements. The effects of co-channel interference before and after the implementation of diversity are also analyzed. To facilitate easy understanding of the models and analysis, the background information in terms of probability and random variables is presented with relevant derivations of densities of linear and nonlinear transformation of random variables, the sums, products, ratios as well as order statistics of random variables of all types. The book also provides material on digital modems of interest in wireless systems. Thus, the book with 1100+ equations and 350+ Matlab generated figures and tables is an ideal source for students, educators, researchers and professionals in wireless communications allowing access to information currently unavailable.