Download or read book Cross layer Resource Allocation for Multi user Communication Systems written by Kibeom Seong and published by . This book was released on 2008 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt: Satisfaction of different QoS demands for various broadband services in wireless networks requires that multi-user packet scheduling intelligently use both channel state information (CSI) and queue state information (QSI). A combination of queue-channel-aware scheduling and power/rate allocation on each transmit dimension is known as "cross-layer resource allocation". This thesis investigates various aspects of cross-layer resource allocation to illustrate its important role in multi-user communication systems. Of particular interest are downlink and uplink wireless systems that use orthogonal frequency division multiplexing (OFDM) modulation and multi-input multi-output (MIMO) transmission with multiple antennas.

Download or read book Cross Layer Resource Allocation For Multiple User Video Communication Systems written by Dawei Wang and published by . This book was released on 2013 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this dissertation, we investigate problems of resource allocation for uplink multiuser wireless communication channels. The users want to upload compressed video streams with different rate-distortion (RD) characteristics to a base station via a multi-carrier channel. The video is organized in groups of pictures (GOP), and the base station makes resource allocation decisions based jointly on the channel state information (CSI) and the RD information to minimize the average video distortion across all users. We first study the case where the channel is slowly varying. With the assumption of the channel staying constant over the duration of a GOP, we derive an optimal condition for minimizing the sum of distortions in a setting of continuous frequency channel response. Our result shows that for a specific band to be assigned to a particular user, the product of the slope of the RD curve of that user and a marginal rate increment corresponding to that band should be maximized. We then design an algorithm which iteratively calculates the status of the RD information and the CSI in a block fading setting. Compared to two baseline resource allocation algorithms that use only a single layer of information, the simulation results show that the cross layer scheme can consistently improve the performance of the system. We then focus on the case of a channel with arbitrary mobility. To better utilize the time varying channel, we design a pilot symbol assisted modulation (PSAM) system which periodically adapts the modulation format according to the instantaneous CSI. We show that the two baseline algorithms with single layer information behave quite differently as the Doppler spread changes, but the cross layer algorithm performs robustly across all different mobile speeds. We further characterize the capacity gain of using the cross layer scheme.

Download or read book Resource Allocation in Multi user Communication Systems written by Jennifer Elizabeth Price and published by . This book was released on 2007 with total page 157 pages. Available in PDF, EPUB and Kindle. Book excerpt: The contributions of this research lie in four main areas: (i) distributed and adaptive rate assignments for CDMA 1xEVDO-type systems, (ii) cross-layer optimal rate assignments for hybrid wired/wireless CDMA networks, (iii) leveraging downlink for socially optimal and incentive compatible uplink rate allocation in cellular networks, and (iv) capacity-achieving rate assignments in unicast networks that employ network coding. In each of these problems, I address issues related to modeling, analysis, implementation, and validation.

Download or read book Cross Layer Resource Allocation in Wireless Communications written by Ana I. Perez-Neira and published by Academic Press. This book was released on 2010-07-28 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cross-Layer Resource Allocation in Wireless Communications offers practical techniques and models for the design and optimisation of cross-layer resource allocation – one of the hottest topics in wireless communications. Resource allocation in wireless networks is traditionally approached either through information theory or communications networks. To break down the barriers between these distinct approaches, this book bridges the physical and network layers by providing cross-layer resource allocation techniques, models, and methodologies. Its unique approach allows optimisation of network resources and will enable engineers to improve signal quality, enhance network and spectrum utilization, increase throughput, and solve the problem of shadowing. Topics covered include different views of spectral efficiency, the role of spatial diversity, of delay in resource allocation, and possible extensions to OFDMA systems. This will be an ideal reference on cross-layer resource allocation between the PHY and MAC layers for R&D and network design engineers and researchers in universities dealing with sensor networks and cognitive systems. - Gives a full description of the characteristics of the PHY layer that promote efficient resource allocation strategies - Gives special emphasis on cross-layer design for spatial diversity schemes - Provides a framework for interaction between the PHY and MAC layers, their parameters of performance and their relationship - Presents resource allocation as a cross-layer design based on an optimization of MAC layer parameters with an accurate model of the PHY layer

Download or read book Using Cross Layer Techniques for Communication Systems written by Rashvand, Habib F. and published by IGI Global. This book was released on 2012-04-30 with total page 656 pages. Available in PDF, EPUB and Kindle. Book excerpt: Although the existing layering infrastructure--used globally for designing computers, data networks, and intelligent distributed systems and which connects various local and global communication services--is conceptually correct and pedagogically elegant, it is now well over 30 years old has started create a serious bottleneck. Using Cross-Layer Techniques for Communication Systems: Techniques and Applications explores how cross-layer methods provide ways to escape from the current communications model and overcome the challenges imposed by restrictive boundaries between layers. Written exclusively by well-established researchers, experts, and professional engineers, the book will present basic concepts, address different approaches for solving the cross-layer problem, investigate recent developments in cross-layer problems and solutions, and present the latest applications of the cross-layer in a variety of systems and networks.

Download or read book Channel Aware Scheduling and Resource Allocation with Cross Layer Optimization in Wireless Networks written by Sheu-Sheu Tan and published by . This book was released on 2013 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: We develop channel aware scheduling and resource allocation schemes with cross-layer optimization for several problems in multiuser wireless networks. We consider problems of distributed opportunistic scheduling, where multiple users contend to access the same set of channels. Instead of scheduling users to the earliest available idle channels, we also take the instantaneous channel quality into consideration and schedule the users only when the channel quality is sufficiently high. This can lead to significant gains in throughput compared to system where PHY and MAC layers are designed separately and the wireless fading channels are abstracted as time invariant, fixed rate channels for scheduling purposes. We first consider opportunistic spectrum access in a cognitive radio network, where a secondary user (SU) share the spectrum opportunistically with incumbent primary users (PUs). Similar to earlier works on distributed opportunistic scheduling (DOS), we maximize the throughput of SU by formulating the channel access problem as a maximum rate-of-return problem in the optimal stopping theory framework. We show that the optimal channel access strategy is a pure threshold policy, namely the SU decides to use or skip transmission opportunities by comparing the channel qualities to a fixed threshold. We further increase the spectrum utilization by interleaving SU's packets with periodic sensing to detect PU's return. We jointly optimize the rate threshold and the packet transmission time to maximize the average throughput of SU, while limiting interference to PU. Next, we develop channel-aware opportunistic spectrum access strategies in a more general cognitive radio network with multiple SUs. Here, we additionally take into account the collisions and complex interaction between SUs and sharing of resources between them. We derive strategies for both cooperative settings where SUs maximize their sum total of throughputs, as well as non-cooperative game theoretic settings, where each SU tries to maximize its own throughput. We show that the optimal schemes for both scenarios are pure threshold policies. In the non-cooperative case, we establish the existence of Nash equilibrium and develop best response strategies that can converge to equilibria, with SUs relying only on their local observations. We study the trade-off between maximal throughput in the cooperative setting and fairness in the non-cooperative setting, and schemes based on utility functions and pricing that mitigate this tradeoff. In addition to maximizing throughput and fair sharing of resources, it is important to consider network/scheduling delays for QoS performance of delay-sensitive applications. We study DOS under both network-wide and user-specific average delay constraints. We take a stochastic Lagrangian approach and characterize the corresponding optimal scheduling policies accordingly, and show that they have a pure threshold structure. Next, we consider the use of different types of channel quality information, i.e., channel state information (CSI) and channel distribution information (CDI) in the opportunistic scheduling design for MIMO ad hoc networks. CSI is highly dynamic in nature and provides time diversity in the wireless channel, but is difficult to track. CDI offers temporal stability, but is incapable of capturing the instantaneous channel conditions. We design a new class of cross-layer opportunistic channel access scheduling framework for MIMO networks where CDI is used in the network context to group the simultaneous transmission links for spatial channel access and CSI is used in the link context to decide when and which link group should transmit based on a pre designed threshold. We thereby reap the benefits of both the temporal stability of CDI and the time diversity of CSI. Finally, we consider a novel application of cross layer optimization for communication of progressive coded images over OFDM wireless fading channels. We first consider adaptive modulation based on the instantaneous channel state information. An algorithm is proposed to allocate power and constellation size at each subchannel by maximizing the throughput. We next consider both the variance and the average of the throughput when deciding the constellation size for adaptive modulation. Simulation results confirm that cross-layer optimization with adaptive modulation enhances system performance.

Download or read book Resource Allocation and Cross layer Control in Wireless Networks written by Leonidas Georgiadis and published by Now Publishers Inc. This book was released on 2006 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt: Information flow in a telecommunication network is accomplished through the interaction of mechanisms at various design layers with the end goal of supporting the information exchange needs of the applications. In wireless networks in particular, the different layers interact in a nontrivial manner in order to support information transfer. In this text we will present abstract models that capture the cross-layer interaction from the physical to transport layer in wireless network architectures including cellular, ad-hoc and sensor networks as well as hybrid wireless-wireline. The model allows for arbitrary network topologies as well as traffic forwarding modes, including datagrams and virtual circuits. Furthermore the time varying nature of a wireless network, due either to fading channels or to changing connectivity due to mobility, is adequately captured in our model to allow for state dependent network control policies. Quantitative performance measures that capture the quality of service requirements in these systems depending on the supported applications are discussed, including throughput maximization, energy consumption minimization, rate utility function maximization as well as general performance functionals. Cross-layer control algorithms with optimal or suboptimal performance with respect to the above measures are presented and analyzed. A detailed exposition of the related analysis and design techniques is provided.

Download or read book Radio Resource Allocation for Multi hop Wireless Networks Using Cross layer Optimization written by Jennifer Catherine Fang and published by . This book was released on 2005 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book On Resource Optimization and Robust CQI Reporting for Wireless Communication Systems written by Ayaz Ahmad and published by . This book was released on 2011 with total page 193 pages. Available in PDF, EPUB and Kindle. Book excerpt: Adaptive resource allocation in wireless communication systems is crucial in order to support the diverse QoS needs of the services and optimize resource utilization. The design of resource allocation schemes should consider the service type for which it is intended. Moreover, due to feedback delay and channel estimation error, the Channel Quality Indicator (CQI) reported to the transmitter may not be a perfect measure of the channel quality and its use for resource allocation may severely degrade the systems performance. In this thesis, we study resource allocation and CQI reporting for wireless networks while taking the aforementioned factors into consideration. First, we consider resource allocation and adaptive modulation in uplink SC-FDMA systems. This is a combinatorial problem whose optimal solution is exponentially complex. We use canonical duality theory to derive a polynomial complexity resource allocation algorithm that provides a nearly optimal solution to the problem. Then, we focus on resource allocation for video streaming in wireless networks with time-varying interference. To this end, by using risk-sensitive control approach, we develop a cross-layer optimization framework that performs power control at the PHY/MAC layer and rate adaptation at the APPLICATION layer jointly and provides fairness among nodes. Finally, by using stochastic control and game theory, we design a robust best-M CQI reporting scheme for multi-carrier and multi-user systems which takes into account the impact of feedback delay and error in CQI computation. Performing resource allocation on the basis of the proposed CQI reporting can significantly improve the system performance.

Download or read book Cross layer Design and Optimization of Heterogeneous Cellular Mobile Networks written by Arman Shojaeifard and published by . This book was released on 2013 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Cross Layer Resource Allocation in Cognitive Radio Networks Models Algorithms and Applications written by Hang Qin and published by Scientific Research Publishing, Inc. USA. This book was released on 2017-04-30 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is about cognitive radio (CR), a revolution in radio technology and an enabling technology for dynamic spectrum access. Due to the unique characteristics of the wireless networks, it is essential to address the approach of multiple layers (e.g., physical, link, and network) to maximize the network performance. The formulation of this cross-layer problem is usually complicated and challenging, while wireless resource allocation is a vital way to handle the race condition of the limited wireless resources. However, given the intrinsic characteristics of cognitive radio networks (CRN), none of the existing analytical approach could be a direct fit. Therefore, innovative theoretical results, along with the corresponding mathematical techniques, are necessary. In this book, we aim to develop some novel algorithmic design and optimization techniques that provide optimal or near-optimal solutions. Although cross-layer design has been introduced to CRN for many years, there are rarely any books for researchers, engineers, and students, from the engineering perspective. From one hand, most of the existing books primarily focus on the mathematical and economic aspects, which are considerably different from the engineering. On the other hand, all of the books mainly aim to system optimization or control techniques, while the cross-layer algorithm design in the distributed environment is usually ignored. As the result, there is an urgent demand for a reference source, which can provide complete information on how to fully adopt cross-layer resource allocation to the CRN. In this regard, this book not only focuses on the description of the main aspects of cross-layer resource allocation over CRN, but also provides a review of the application solutions. In a nutshell, it provides a specific treatment of cross-layer design in CRN. The topics range from the basic concepts of cross-layer resource allocation, to the state-of-the-art analyses, modelings, and optimizations for CRN.

Download or read book Performance Limits and Optimal Resource Allocation for Coded Multi user Communication Systems written by Dennis Lee Goeckel and published by . This book was released on 1996 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Machine Learning for Future Wireless Communications written by Fa-Long Luo and published by John Wiley & Sons. This book was released on 2020-02-10 with total page 490 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive review to the theory, application and research of machine learning for future wireless communications In one single volume, Machine Learning for Future Wireless Communications provides a comprehensive and highly accessible treatment to the theory, applications and current research developments to the technology aspects related to machine learning for wireless communications and networks. The technology development of machine learning for wireless communications has grown explosively and is one of the biggest trends in related academic, research and industry communities. Deep neural networks-based machine learning technology is a promising tool to attack the big challenge in wireless communications and networks imposed by the increasing demands in terms of capacity, coverage, latency, efficiency flexibility, compatibility, quality of experience and silicon convergence. The author – a noted expert on the topic – covers a wide range of topics including system architecture and optimization, physical-layer and cross-layer processing, air interface and protocol design, beamforming and antenna configuration, network coding and slicing, cell acquisition and handover, scheduling and rate adaption, radio access control, smart proactive caching and adaptive resource allocations. Uniquely organized into three categories: Spectrum Intelligence, Transmission Intelligence and Network Intelligence, this important resource: Offers a comprehensive review of the theory, applications and current developments of machine learning for wireless communications and networks Covers a range of topics from architecture and optimization to adaptive resource allocations Reviews state-of-the-art machine learning based solutions for network coverage Includes an overview of the applications of machine learning algorithms in future wireless networks Explores flexible backhaul and front-haul, cross-layer optimization and coding, full-duplex radio, digital front-end (DFE) and radio-frequency (RF) processing Written for professional engineers, researchers, scientists, manufacturers, network operators, software developers and graduate students, Machine Learning for Future Wireless Communications presents in 21 chapters a comprehensive review of the topic authored by an expert in the field.

Download or read book Multiuser Resource Allocation in Multichennel Wireless Communication Systems written by Zukang Shen and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Optimization Methods for User Admissions and Radio Resource Allocation for Multicasting over High Altitude Platforms written by Ibrahim, Ahmed and published by River Publishers. This book was released on 2019-02-27 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on the issue of optimizing radio resource allocation (RRA) and user admission control (AC) for multiple multicasting sessions on a single high altitude platform (HAP) with multiple antennas on-board. HAPs are quasi-stationary aerial platforms that carry a wireless communications payload to provide wireless communications and broadband services. They are meant to be located in the stratosphere layer of the atmosphere at altitudes in the range 17-22 km and have the ability to fly on demand to temporarily or permanently serve regions with unavailable telecommunications infrastructure. An important requirement that the book focusses on is the development of an efficient and effective method for resource allocation and user admissions for HAPs, especially when it comes to multicasting. Power, frequency, space (antennas selection) and time (scheduling) are the resources considered in the problem over an orthogonal frequency division multiple access (OFDMA) HAP system. Due to the strong dependence of the total number of users that could join different multicast groups, on the possible ways we may allocate resources to these groups, it is of significant importance to consider a joint user to session assignments and RRA across the groups. From the service provider's point of view, it would be in its best interest to be able to admit as many higher priority users as possible, while satisfying their quality of service requirements. High priority users could be users subscribed in and paying higher for a service plan that gives them preference of admittance to receive more multicast transmissions, compared to those paying for a lower service plan. Also, the user who tries to join multiple multicast groups (i.e. receive more than one multicast transmission), would have preferences for which one he would favor to receive if resources are not enough to satisfy the QoS requirements. Technical topics discussed in the book include: Overview on High Altitude Platforms, their different types and the recent works in this areaRadio Resource Allocation and User Admission Control in HAPsMulticasting in a Single HAP System: System Model and Mathematical FormulationOptimization schemes that are designed to enhance the performance of a branch and bound technique by taking into account special mathematical structure in the problem formulation

Download or read book Physical and Cross Layer Security Enhancement and Resource Allocationfor Wireless Networks written by Muhammad Shafi Al Bashar and published by . This book was released on 2011 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this dissertation, we present novel physical (phy) and cross-layer design guidelines and resource adaptation algorithms to improve the security and user experience in the future wireless networks. Physical and cross-layer wireless security measures can provide stronger overall security with high efficiency and can also provide better flexibility in response to the typically time-varying wireless environment. To better utilize limited wireless resources, we present approaches and techniques based on new performance criteria for wireless system optimization by thoroughly exploiting user information including its Quality of Service (QoS) requests and channel state information (csi) to improve network throughput and security. In recent years, there has been a growing research interest in wireless system security from phy layer perspective. In a wiretap channel model introduced in the seminal work by Wyner, a sender "Alice" wishes to transmit a secret message to the intended receiver "Bob" in presence of a passive eavesdropper "Eve". Existing works have characterized maximum achievable secrecy rate or secrecy capacity for single- and multiple-antenna systems by applying Gaussian signaling and secrecy code. Despite the impracticality of Gaussian input, its compact closed-form expression of mutual information motivated the wide use of Gaussian input assumption in theoretical analysis. In contrast to the Gaussian codebook, practical wiretap codes must consist of finite-alphabet symbols. Because of this constraint, the achievable secrecy rate for a finite-alphabet input scenario would differ from the secrecy rate achievable by a Gaussian codebook. In this thesis, we quantify the effect of finite discrete-constellation on instantaneous and ergodic secrecy rate of multiple-antenna wire-tap channels. Our results demonstrate substantial performance difference between systems involving finite-alphabet inputs and systems with Gaussian inputs. In addition, we investigate the secrecy performance of multi-terminal wiretap systems when a codebook based transmission beamforming is implemented. We characterize the secrecy outage probability of a communication link under eavesdropping. We consider a limited feedback scenario where the transmitter uses a pre-defined codebook known to both the transmitter and the receiver for beamforming, and analyze the secrecy outage probability of the link when it being eavesdropped. Next, we consider the security of wireless multi-hop networks. Certainly, network security is an overarching issue that transcends all layers of communication protocol stack. Therefore, we tackle the problem of network security by proper user scheduling, routing, and resource management. Our approach of secrecy is complementary to the traditional cryptography based techniques. Together, they can provide stronger overall security and flexibility in selecting the desired solution and can reduce bandwidth and energy overhead as much as possible. Multi-hop wireless networks frequently employ the traditional routing and resource allocation strategies. Such strategies often fail to take into account the additional need for protection against security vulnerabilities due to the wireless medium. Thus, to address security concerns, we investigate the problem of eavesdropping control by proposing security-aware power allocation strategies and routing algorithms for multi-hop networks. The future wireless infrastructure will consists of a plethora of heterogeneous collections of applications and services. A differentiated service structure would therefore be an essential part of the future wireless infrastructure. In addition to the security consideration of wireless network, we focus on the heterogeneous structure of the network. We study the problem of cross-layer resource allocation and admission control in a multiuser heterogeneous ofdma network providing both QoS-constrained user services and best-effort services. Such heterogeneous networks provide service to both High-Priority (hp) users and Best-Effort (be) users. By clustering subcarriers, efficient algorithms for cluster and power allocation have been proposed. Our strategy maximizes the total network utility of the be users while satisfying the QoS request for maximum number of hp users. The feasibility of the resource allocation problem depends on the number of hp users in the network. Since a large number of demanding hp users would render the resource allocation problem infeasible, a joint admission control and resource allocation scheme could be an efficient way of tackling both problems with less overhead. By incorporating admission control, we propose an efficient and optimal joint admission control and resource allocation algorithm. [The dissertation citations contained here are published with the permission of ProQuest llc. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.].

Download or read book Resource Allocation in Heterogeneous Multi hop Cellular Networks written by Mahdi Shabany and published by LAP Lambert Academic Publishing. This book was released on 2009-08 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt: A novel framework to model the problem of downlink resource allocation in conventional cellular systems and multi-hop cellular networks is presented. In conventional cellular CDMA systems, we use the dynamic pricing platform to formulate downlink resource allocation based on a novel defined cross-layer utility function. This utility function quantifies the degree of utilization of resources. Unlike the previous works, we solve the problem with the general objective of maximizing the total network utility instead of achieved utility of each Base Station (BS). In the second part of the book, we consider the problem of downlink resource allocation in multi- hop cellular networks where, using the concept of capacity regions, an algorithm for joint optimum rate allocation and routing scheme is proposed to maximize the total throughput of multi-hop cellular CDMA networks. The notion of infeasibility factor is then defined and used to propose an adaptive scheme on top of the above algorithm to manage fundamental coverage-capacity tradeoff for the downlink.