Platform Interference In Wireless Systems

Intra-system EMC problems are becoming increasingly common in mobile devices, ranging from notebook PCs to cell phones, with RF/wireless capbilities. These issues range from minor annoyances to serious glitches which impede the functioning of the device. This book gives a thourough review of electromagnetic theory (including Maxwell's equations), discusses possible sources and causes of intra-system interference, shows to use models and analysis to discover potential sources of intra-system EMC in a design, how to use appropriate tests and measurements to detect intra-system EMC problems, and finally extensively discusses measures to mitigate or totally eliminate intra-system EMC problems. With more and more mobile devices incorporating wirless capability (often with multiple wireless systems, such as Bluetooth and WiFi), this book should be part of the reference shelf of every RF/wireless engineer and mobile device designer. *Addresses a growing problem in RF/wireless devices----interference created inside the devices, which impair their operation *Covers devices, ranging from laptop PCs to mobile phones to Bluetooth headsets *Explains the sources of such intra-system interference, how to detect and measure such interference, design techniques for mitigating the interference, and proven techniques for eliminating the interference

The wireless medium is a shared resource. If nearby devices transmit at the same time, their signals interfere, resulting in a collision. In traditional networks, collisions cause the loss of the transmitted information. For this reason, wireless networks have been designed with the assumption that interference is intrinsically harmful and must be avoided. This book, a revised version of the author's award-winning Ph.D. dissertation, takes an alternate approach: Instead of viewing interference as an inherently counterproductive phenomenon that should to be avoided, we design practical systems that transform interference into a harmless, and even a beneficial phenomenon. To achieve this goal, we consider how wireless signals interact when they interfere, and use this understanding in our system designs. Specifically, when interference occurs, the signals get mixed on the wireless medium. By understanding the parameters of this mixing, we can invert the mixing and decode the interfered packets; thus, making interference harmless. Furthermore, we can control this mixing process to create strategic interference that allow decodability at a particular receiver of interest, but prevent decodability at unintended receivers and adversaries. Hence, we can transform interference into a beneficial phenomenon that provides security. Building on this approach, we make four main contributions: We present the first WiFi receiver that can successfully reconstruct the transmitted information in the presence of packet collisions. Next, we introduce a WiFi receiver design that can decode in the presence of high-power cross-technology interference from devices like baby monitors, cordless phones, microwave ovens, or even unknown technologies. We then show how we can harness interference to improve security. In particular, we develop the first system that secures an insecure medical implant without any modification to the implant itself. Finally, we present a solution that establishes secure connections between any two WiFi devices, without having users enter passwords or use pre-shared secret keys.

Interference Avoidance Methods for Wireless Systems is an introduction to wireless techniques useful for uncoordinated unlicensed band systems, which use adaptive transmitters and receivers. The book provides a comprehensive theoretical analysis of interference avoidance algorithms in a general signal space framework that applies to a wide range of wireless communication scenarios with multiple users accessing the same communication resources. This book will be of interest to researchers, graduate students, and engineers working in the area of wireless communications as well as to technology policy makers working on radio frequency spectrum allocation. The book can also be used as a supplement text to advanced topics graduate courses in the area of wireless communication systems.

This leading-edge resource offers you a new methodology for analyzing and studying the behavior of wireless communication systems in an interference environment. It provides you with modern tools and techniques for use in real-world applications that help you guarantee optimum system performance. The book treats both additive and multiplicative interfering signals, including in-depth descriptions of how these signals behave, regardless of the source.

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.

Wireless Communication Systems: Advanced Techniques for Signal Receptionoffers a unified frameworkfor understanding today's newest techniques for signal processing in communication systems - andusing them to design receivers for emerging wireless systems. Two leading researchers cover a fullrange of physical-layer issues, including multipath, dispersion, interference, dynamism, andmultiple-antenna systems. Topics include blind, group-blind, space-time, and turbo multiuserdetection; narrowband interference suppression; Monte Carlo Bayesian signal processing; fast fadingchannels; advanced signal processing in coded OFDM systems, and more.

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.

The book describes how interference can be managed so that radio systems co-exist, without harmful mutual effects, within a finite amount of spectrum. This is timely in view of the increasing proliferation of wireless systems. It covers both the processes, such as regional or international coordination, as well as the engineering principles. Written by an author with extensive experience in the industry, it describes in detail the main methodologies for calculating or computing the interference between radio systems of the same type, and also between radio systems of different types