Network Interference Management Via Interference Alignment
Download Network Interference Management Via Interference Alignment PDF/ePub or read online books in Mobi eBooks. Click Download or Read Online button to get Network Interference Management Via Interference Alignment book now. This website allows unlimited access to, at the time of writing, more than 1.5 million titles, including hundreds of thousands of titles in various foreign languages.
Network Interference Management Via Interference Alignment
Currently, we are witnessing a veritable explosion in the number of mobile devices with network connectivity. This explosion in the number of mobile devices which guzzle data is resulting in bandwidth becoming an increasingly scarce resource. The surge in the demand for data calls for new techniques to understand and improve the capacity (data rates) of wireless networks. In this thesis, I will describe and explore the benefits of interference alignment - a recently discovered technique to manage interference, which is the primary bottleneck of rates of communication in wireless communication networks. A primary object of study of this thesis is a communication network with K wireless transmitter-receiver pairs mutually interfering with each other, also known as the K user interference network. In this thesis, we study a high SNR approximation to its capacity known as the degrees of freedom. A widely held belief that influences design of most, if not all wireless networks is the following: in the K user interference network it is optimal from a network degrees of freedom perspective to divide the spectrum among the users like cutting a cake. This cake cutting view of spectrum access also known as orthogonalization enables each user in the interference network to get a fraction of 1/K degrees of freedom, i.e., 1/K of the spectrum free of interference. In this thesis, we will show that, from a degrees of freedom perspective, the belief in the optimality of the cake cutting view of spectrum access (i.e., orthogonalization) is flawed. We show that if the network is frequency-selective or time-varying, then each of the K users of an interference network can essentially get half the degrees of freedom of a single user (i.e., half the spectrum at high signal-to-noise ratios) simultaneously. In other words, each user can get ``half the cake'' rather than merely a fraction 1/K. The key to achieving this is the powerful interference management strategy of interference alignment. The thesis will study and develop various aspects of interference alignment. First, we develop an asymptotic alignment scheme to achieve ``half the cake'' in frequency-selective/time-varying interference channels. We then extend the idea of interference alignment to channels that are not frequency-selective or time-varying (i.e., channels which are constant) via three approaches: asymmetric complex signaling, a deterministic approach, and a distributed (numerical) alignment algorithm. In each of these cases, we will demonstrate degrees of freedom and capacity benefits of interference alignment in wireless interference networks. We also demonstrate practical benefits of the third approach - distributed alignment - in terms of rates at moderate signal-to-noise ratios and distributed implementations. Finally, we show that the impact of interference alignment extends beyond the context of just wireless systems. In particular, we explore an alternate application of the idea of alignment - erasure codes for distributed storage systems.
Interference Management Via Interference Alignment in Wireless Networks
In wireless communication networks, competition among users for channel resources can result in severe mutual interference. This is a bottleneck for obtaining higher communication rates. Recent advances in the network information theory, such as the idea of interference alignment, have greatly facilitated our understanding of signal dimensions or even exact capacity of wireless networks and produced a number of new transmission schemes to achieve higher rates. Usually, we are interested in the fundamental questions -- what is the channel capacity of multiuser networks, and how to achieve higher communication rates, attractive for both theoretical researchers and engineers. Since finding the exact capacity of multiuser wireless networks is quite challenging, if not impossible, we are interested in the degrees of freedom (DoF) characterization, i.e., a coarse capacity approximation, of wireless networks. The number of DoF of a communication network is a metric of great significance as it provides a lens into the most essential aspects of the communication problem. DoF investigations have motivated many fundamental ideas such as interference alignment. In this dissertation, we investigate the DoF of a number of multiuser wireless networks using the idea of interference alignment. In particular, we start from the classical interference channels with global channel knowledge at each node. A number of scenarios will be studied, including networks with single antenna or multiple antennas at each node. Next, we consider the interference channel with local cooperation and local connectivity. Then we go beyond one-hop to multihop wireless networks where we find the DoF of multiple unicast for 2-source 2-sink layered networks with arbitrary topologies. Finally, we weaken the global channel knowledge assumption, to study broadcast channels with no channel state information at the transmitter. Several interesting tools, insights and surprising results are obtained in this work -- including phase alignment, asymmetric complex signaling, subspace alignment chains, genie chains, the observation that removing interference-carrying links can reduce the channel capacity, and blind interference alignment.
Resource Management in Advanced Wireless Networks
RESOURCE MANAGEMENT IN ADVANCED WIRELESS NETWORKS Written and edited by a team of experts in the field, this exciting new volume provides a comprehensive exploration of cutting-edge technologies and trends in managing resources in advanced wireless networks. This groundbreaking new volume from Wiley-Scrivener discusses the challenges that are emerging while managing the resources in various wireless networking technologies. Initially, the evolution of wireless networking technologies is presented, focusing on the advantages of improving data rates and data reliability. The book then goes through the various architecture designs based on the network paradigms, along with the evolution of networks based on the trends in the telecommunication industry. Various salient features are highlighted in managing resources, and the role of routing strategies is addressed with regard to real-time applications. Covering resource management in wireless networks, various industries are covered, such as healthcare and financial services, but the ideas are useful across many industries. Whether for the veteran engineer, industry professional, or student, this is a must- have for any library.