Topological Interference Management for Multi-user Wireless Networks PDF Download

Author: Hassan Kallam
Publisher:
ISBN:
Category :
Languages : en
Pages : 94

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Book Description
Topological Interference Management (TIM) allows studying the Degrees of Freedom (DoF) of partially connected linear interference communication networks, where the Channel State Information at the Transmitter (CSIT) is restricted to the topology of the network, i.e., a knowledge of which interference links are weak and which are strong. In this thesis, we consider TIM for infinite downlink cellular networks in the one-dimensional (1D) linear and the two-dimensional (2D) hexagonal models. We consider uniformly distributed users in each cellular cell, effectively creating a continuous distribution of users, aiming to study user classes based on different interference profiles rather than on actual individual users' positions. We also consider the construction of the TIM network topology by analyzing different interference thresholds. Unlike previous works, we use TIM at the user class level to find the system's DoF independent of the actual user position. Then, after proposing a fractional coloring scheme that can achieve the optimal DoF solution, a trade-off between DoF and Signal to Interference Ratio (SIR) is given. This thesis also presents a new approach to construct an interference topology for the unicast TIM problem of multi-user wireless networks. Based on our interference topology construction approach, we are able to evaluate the achievable rate's theoretical limit, in the asymptotic Signal to Noise Ratio (SNR) regime, for the underlying wireless network and not just for its topological interference representation. This new approach allows us to cope with the finite SNR regime and not just with the asymptotic SNR regime with the DoF analysis. A new SNR independent interference threshold parameter is proposed and we evaluate the achievable symmetric rates of the wireless network in both the finite SNR regime and the asymptotic SNR regime. Then, we present outer bound solutions on the new normalized interference threshold parameter for interference topologies with half-DoF-feasibility, considering both an orthogonal resource allocation and Interference Alignment (IA). These bounds specify if a given half-DoF-feasible interference topology can be, in terms of the achievable rate, the best topology or not. Using this result, we limit the search space in the normalized interference threshold parameter range, to find half-DoF-feasible interference topologies having the possibility to be the best topologies in terms of the achievable rate. Finally, this thesis considers a case study on TIM for small-scale wireless networks, in which, we consider the TIM problem for four users wireless networks using our proposed interference topology construction approach. Then, we apply the achievable rates analysis, proposed under the new interference topology construction approach, for all interference topologies with half-DoF-feasibility, through both orthogonal sharing and IA, in the TIM problem of four users wireless networks.

Author: Venugopal V. Veeravalli
Publisher: Cambridge University Press
ISBN: 131673272X
Category : Technology & Engineering
Languages : en
Pages : 227

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Book Description
Learn about an information-theoretic approach to managing interference in future generation wireless networks. Focusing on cooperative schemes motivated by Coordinated Multi-Point (CoMP) technology, the book develops a robust theoretical framework for interference management that uses recent advancements in backhaul design, and practical pre-coding schemes based on local cooperation, to deliver the increased speed and reliability promised by interference alignment. Gain insight into how simple, zero-forcing pre-coding schemes are optimal in locally connected interference networks, and discover how significant rate gains can be obtained by making cell association decisions and allocating backhaul resources based on centralized (cloud) processing and knowledge of network topology. Providing a link between information-theoretic analyses and interference management schemes that are easy to implement, this is an invaluable resource for researchers, graduate students and practicing engineers in wireless communications.

Author: Ilan Shomorony
Publisher:
ISBN: 9781601989055
Category : Multiuser detection (Telecommunication)
Languages : en
Pages : 131

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Book Description
Multi-hop communication paradigms are expected to play a central role in future wireless networks by enabling a higher spatial reuse of the spectrum. A major challenge in multi-hop multi-user (or multi-flow) wireless networks is that "interference management" and "relaying" are coupled with each other. In other words, wireless relay nodes must play a dual role: they serve as intermediate steps for multi-hop communication and as part of the mechanism that allows interference management schemes. Nonetheless, in the communications, networking and information theory literature, these two tasks have traditionally been addressed separately, and the fundamental principles of the "wireless networks of the future" are currently not well understood. In this monograph, we take a unified approach to relaying and interference management, and seek to develop tools to study the fundamentals of multi-hop multi-flow wireless networks.

Author: Seyyed Hassan Mahboubi
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Spectrum sharing is known as a key solution to accommodate the increasing number of users and the growing demand for throughput in wireless networks. Interference is the primary barrier to enhancing the overall throughput of the network, especially in the medium and high signal to noise ratios (SNRs). Managing interference to overcome this barrier has emerged as a crucial step in developing efficient wireless networks. An interference management strategy, named interference Alignment, is investigated. It is observed that a single strategy is not able to achieve the maximum throughput in all possible scenarios, and in fact, a careful design is required to fully exploit all available resources in each realization of the system. In this dissertation, the impact of interference on the capacity of X networks with multiple antennas is investigated. Degrees of freedom (DoF) are used as a figure of merit to evaluate the performance improvement due to the interference management schemes. A new interference alignment technique called layered interference alignment, which enjoys the combined benefits of both vector and real alignment is introduced in this thesis. This technique, which uses a type of Diophantine approximation theorems first introduced by the author, is deployed and was proved to enable the possibility of joint decoding among the antennas of a receiver. With a careful transmitter signal design, this method characterizes the total DoF of multiple-input multiple-output (MIMO) X channels. Then, this result is used to determine the total DoF of two families of MIMO X channels. The Diophantine approximation theorem is also extended to the field of complex numbers to accommodate the complex channel realizations as well.

Author: Jiandong Li
Publisher: Artech House
ISBN: 1630815098
Category : Technology & Engineering
Languages : en
Pages : 213

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Book Description
This authoritative resource offers a comprehensive overview of heterogeneous wireless networks, small cells, and device-to-device (D2D) communications. The book provides insight into network modeling and performance analysis of heterogeneous wireless networks. Interference management framework and design issues are covered as well as details about resource mobility, channel models, and typical and statistical interference modeling. This resource explains leveraging resource heterogeneity in interference mitigation and presents the challenges and feasible solutions for concurrent transmission. Moreover, complete coverage of interference alignment in MIMO heterogeneous networks for both downlink and uplink is presented. This book provides performance results for an ideal partially connected interference network as well as a practical heterogeneous network. Readers find practical guidance for LTE and LTE-Advanced as well as 5G in this resource. New techniques and designs for heterogeneous wireless networks are included.

Author: Chenwei Wang
Publisher:
ISBN: 9781267836403
Category :
Languages : en
Pages : 237

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Book Description
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.

Author: Daniel Zahavi
Publisher:
ISBN:
Category :
Languages : en
Pages : 204

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Book Description

Author: Chia-Chi Huang
Publisher:
ISBN: 9781109246001
Category :
Languages : en
Pages : 108

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Book Description
Interference is a key property of wireless communications due to the broadcasting nature of wireless links. The design of wireless networks needs to put interference management into consideration. Traditionally, interference management is done by partitioning the whole network into orthogonal non-interfering channels via time- or frequency-division multiplexing. While orthogonalization significantly reduces the complexity of the design and implementation of wireless networks, it also introduces artificial restriction and leads to suboptimal performance. This thesis is devoted to the design and analysis of interference management from a cross-layer perspective. The key to increase spectrum efficiency of a wireless network is to treat the entire network as a channel rather than viewing them as a set of separate links. Based on this idea, we propose three interference management schemes and evaluate the fundamental limits associated with them. We use the notions of both conventional and generalized degrees of freedom (DOF), which are two widely-used approximations of channel capacity, as merits to evaluate and compare the performance improvement brought by the interference management schemes. The thesis consists of four main results. First, we consider a multiple-input-multiple-output (MIMO) 2-suer cognitive radio system in an information theoretic setting where some messages are made available, by a genie, to some nodes (other than the intended nodes) non-causally, noiselessly, and for free. We find the DOF region of this system and show that this region is larger than the one without cognitive message sharing. Our results also show that in general it may be more beneficial, in terms of sum DOF, for a user to have a cognitive transmitter than to have cognitive receiver. Second, we consider a MIMO Gaussian interference channel with user cooperation, including cooperation at transmitters only, at receivers only, and at transmitters as well as receivers. We find the DOF region of this system and obtain a negative result that allowing users to cooperate does not enlarge the DOF region of this channel. Third, we explore the capacity and generalized degrees of freedom (GDOF) of a 2-user Gaussian X channel, i.e. a generalization of the 2-user interference channel where there is an independent message from each transmitter to each receiver. We provide the GDOF characterization of the channel under a symmetric setting. We also identify the regime where interference alignment is helpful so that the X channel has a higher capacity than the underlying symmetric interference channel. We further extend the noisy interference capacity characterization previously obtained for the interference channel to the X channel. Lastly, we study the effect of the absence of channel knowledge for MIMO networks. In particular, we assume perfect channel state information at the receivers and no channel state information at the transmitter(s). We provide the characterization of the DOF region for a 2-user MIMO broadcast channel. We then use the result of the broadcast channel to find the DOF region for some special cases of a 2-user MIMO interference channel.

Author: Syed A. Jafar
Publisher: Now Publishers Inc
ISBN: 160198474X
Category : Computers
Languages : en
Pages : 147

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Book Description
Interference Alignment: A New Look at Signal Dimensions in a Communication Network provides both a tutorial and a survey of the state-of-art on the topic.

Author: Seyed Javad Kazemitabar
Publisher: Springer Science & Business Media
ISBN: 9048199905
Category : Technology & Engineering
Languages : en
Pages : 109

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Book Description
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.