Download or read book Improving Efficiency of Wireless Networks Using Network Optimized Beamforming Virtual Terrain Leveling and High performance Computing written by Vinay Bharadwaj Ramakrishnaiah and published by . This book was released on 2018 with total page 131 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wireless communication is sensitive to ambient noise as well as interference due to the use of a shared medium, unlike wired communication. The range of frequencies used for wireless communication is limited, which prompts the reuse of frequencies causing increased interference. Wireless devices are often portable or mobile units with limited battery capacity, which makes effective low-power communication in harsh noise environments a high priority. In addition, wireless communication is significantly affected by the surrounding terrain like buildings, hills, foliage, etc. Many of these problems can be addressed through careful antenna design. Typically, omni-directional antennas are used in wireless communication due to their relative simplicity. These antennas radiate signal equally in all directions resulting in a waste of transmitter power and a source of interference to other nodes. More sophisticated techniques are available, but these can be challenging as they require complex software, which in turn demands powerful and expensive hardware. Use of adaptive directional antenna arrays can minimize interference while also being more energy efficient. Such “smart antennas” use digital beamforming based on signal processing algorithms to compute the appropriate weights to form effective antenna patterns. Smart antennas require the knowledge of the signal received at each antenna in the antenna array, thereby increasing the complexity of hardware and cost. Analog beamforming is a low hardware complexity alternative to smart antennas, which relies on a single transceiver and power splitter/combiner. Computer controlled analog amplifiers and phase shifters are used to form the desired beam patterns. The disadvantage of analog beamforming is that the computer only has access to the combined signals in the antenna array. We use analog beamforming in our implementation along with Noise-to-Signal ratio of nearby communicating nodes to mitigate this disadvantage. Conventional smart antennas optimize results for each individual node, while it is preferable to have a global optimal solution. It is also possible to compute the antenna array weights to adapt to the radio propagation characteristics of the surrounding terrain. This requires the knowledge of path loss at various distances and directions from the transmitter calculated using one of several available path loss models to compute a radio propagation map. This research has the following objectives: The first objective is to develop a new analog beamforming technique using Noise-to-Signal ratio as the performance measure. An iterative algorithm is developed that uses distributed node information along with analog beamforming, instead of individual antenna information. The antenna weights are sequentially adjusted across all nodes in the route to achieve optimization across the network. This provides a network optimized, low cost and hardware complexity solution for adaptive beamforming. The second objective is to explore another novel method called Virtual Terrain Leveling (VTL) where the effects of the terrain are virtually nullified using antenna arrays up to a specified distance from the transmitter. This work investigates whether VTL can mitigate the difficulties that the terrain features pose for implementation of wireless networks by attempting to provide uniform propagation in the presence of terrain with the use of directional antennas. The final objective is to use high performance computing (HPC) to develop more efficient storage and processing of radio propagation maps. Processing and storage of radio propagation maps can be computationally intensive based on the area and the resolution of the map. The technique of adaptive region construction is developed to efficiently store radio propagation maps while preserving the shape of the external contour for a given set of points. A GPU implementation of the algorithm with optimizations tailored to the hardware shows possible near - real time performance.

Download or read book Millimeter Wave Networks written by Peng Yang and published by Springer Nature. This book was released on 2021-10-27 with total page 169 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a comprehensive review and in-depth study on efficient beamforming design and rigorous performance analysis in mmWave networks, covering beam alignment, beamforming training and beamforming-aided caching. Due to significant beam alignment latency between the transmitter and the receiver in existing mmWave systems, this book proposes a machine learning based beam alignment algorithm for mmWave networks to determine the optimal beam pair with a low latency. Then, to analyze and enhance the performance of beamforming training (BFT) protocol in 802.11ad mmWave networks, an analytical model is presented to evaluate the performance of BFT protocol and an enhancement scheme is proposed to improve its performance in high user density scenarios. Furthermore, it investigates the beamforming-aided caching problem in mmWave networks, and proposes a device-to-device assisted cooperative edge caching to alleviate backhaul congestion and reduce content retrieval delay. This book concludes with future research directions in the related fields of study. The presented beamforming designs and the corresponding research results covered in this book, provides valuable insights for practical mmWave network deployment and motivate new ideas for future mmWave networking. This book targets researchers working in the fields of mmWave networks, beamforming design, and resource management as well as graduate students studying the areas of electrical engineering, computing engineering and computer science. Professionals in industry who work in this field will find this book useful as a reference.

Download or read book Communication Efficient Federated Learning for Wireless Networks written by Mingzhe Chen and published by Springer Nature. This book was released on with total page 189 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Improving the Performance and Efficiency of Wireless Networks Using Rate Adaptation written by Muhammad Owais Khan and published by . This book was released on 2015 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent years have seen a staggering increase in the deployment and utilization of wireless networks. More and more devices are being equipped with Wireless LAN (WLAN) cards to take advantage of the omnipresence of WLAN networks. Therefore, it has become necessary that the protocols used by WLANs are efficient and provide good performance. Rate Adaptation protocols are an important mechanism employed by WLANs to improve network performance. This dissertation develops three complementary techniques, which use rate adaptation to optimize and improve performance by i) performing rate adaptation to optimize energy consumption, ii) developing a more accurate technique to predict the frame delivery ratio that is used by rate adaptation protocols, and iii) jointly optimizing rate adaptation with data retransmission to maximize throughput. More specifically, in i), we use extensive measurements to develop a simple yet accurate energy consumption model for 802.11n wireless cards. We use the model to drive the design of an energy aware rate adaptation scheme. A major benefit of a model-based rate adaptation is that applying a model allows us to eliminate frequent probes required in many existing rate adaptation schemes. In ii), we find that the accuracy of existing delivery ratio calculation techniques is still limited due to bursty errors inherent to the wireless channel. We develop a new method for computing packet delivery rate that captures the burstiness of errors. Furthermore, we propose a new data interleaving technique, which leverages our framework to reduce the burstiness of errors, thereby improving frame delivery ratio. Finally, in iii), we address the susceptibility of wireless networks to transmission failures due to dynamic channel conditions and unpredictable interference. To efficiently recover from failures, we propose a retransmission scheme where the receiver combines information received from multiple failed transmissions associated with the same frame. The protocol has two distinguishing features. First, it simultaneously supports partial retransmission and combines bits with low confidence. Second, it jointly optimizes the data rate of the retransmission and the information to be retransmitted to maximize throughput.

Download or read book Improving the Performance of Wireless LANs written by Nurul Sarkar and published by CRC Press. This book was released on 2014-01-08 with total page 474 pages. Available in PDF, EPUB and Kindle. Book excerpt: While there are countless books on wireless networks, few actually quantify the key performance-limiting factors of wireless local area networks (WLANs) and describe various methods for improving WLAN performance. Fulfilling these needs, Improving the Performance of Wireless LANs: A Practical Guide provides both theoretical background and empirical results for the optimum planning and deployment of high performance WLAN systems in different residential and commercial buildings. Useful to students, faculties, researchers, engineers, and network developers, this must-have book not only explains the fundamentals of WLAN systems, including WLAN features and standards, but also: Supplies strategic guidelines for WLAN system design, modeling, and performance evaluation Includes radio propagation and site measurements as well as simulations for various network design scenarios Discusses environmental effects on WLAN performance, protocol redesign for routing and MAC, and traffic distribution Contains numerous illustrations and examples, plus chapter summaries, review questions, reading lists, mini-projects, an extensive glossary, and a list of acronyms Examines emerging and future network technologies, such as next generation Wi-Fi (802.11ac), very high throughput Wi-Fi (802.11ad), wireless mesh networking (802.11s), emergency QoS (802.11u), and vehicle-to-vehicle communications (802.11p) Improving the Performance of Wireless LANs: A Practical Guide makes the teaching, learning, and researching of advanced wireless network design and performance a more active process by using practical tools and exercises to add life to this highly technical subject.

Download or read book Federated Learning for Wireless Networks written by Choong Seon Hong and published by Springer Nature. This book was released on 2022-01-01 with total page 257 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recently machine learning schemes have attained significant attention as key enablers for next-generation wireless systems. Currently, wireless systems are mostly using machine learning schemes that are based on centralizing the training and inference processes by migrating the end-devices data to a third party centralized location. However, these schemes lead to end-devices privacy leakage. To address these issues, one can use a distributed machine learning at network edge. In this context, federated learning (FL) is one of most important distributed learning algorithm, allowing devices to train a shared machine learning model while keeping data locally. However, applying FL in wireless networks and optimizing the performance involves a range of research topics. For example, in FL, training machine learning models require communication between wireless devices and edge servers via wireless links. Therefore, wireless impairments such as uncertainties among wireless channel states, interference, and noise significantly affect the performance of FL. On the other hand, federated-reinforcement learning leverages distributed computation power and data to solve complex optimization problems that arise in various use cases, such as interference alignment, resource management, clustering, and network control. Traditionally, FL makes the assumption that edge devices will unconditionally participate in the tasks when invited, which is not practical in reality due to the cost of model training. As such, building incentive mechanisms is indispensable for FL networks. This book provides a comprehensive overview of FL for wireless networks. It is divided into three main parts: The first part briefly discusses the fundamentals of FL for wireless networks, while the second part comprehensively examines the design and analysis of wireless FL, covering resource optimization, incentive mechanism, security and privacy. It also presents several solutions based on optimization theory, graph theory, and game theory to optimize the performance of federated learning in wireless networks. Lastly, the third part describes several applications of FL in wireless networks.

Download or read book Robust Resource Allocation in Future Wireless Networks written by Saeedeh Parsaeefard and published by Springer. This book was released on 2017-03-06 with total page 255 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents state-of-the-art research on robust resource allocation in current and future wireless networks. The authors describe the nominal resource allocation problems in wireless networks and explain why introducing robustness in such networks is desirable. Then, depending on the objectives of the problem, namely maximizing the social utility or the per-user utility, cooperative or competitive approaches are explained and their corresponding robust problems are considered in detail. For each approach, the costs and benefits of robust schemes are discussed and the algorithms for reducing their costs and improving their benefits are presented. Considering the fact that such problems are inherently non-convex and intractable, a taxonomy of different relaxation techniques is presented, and applications of such techniques are shown via several examples throughout the book. Finally, the authors argue that resource allocation continues to be an important issue in future wireless networks, and propose specific problems for future research.

Download or read book Advances on Broadband and Wireless Computing Communication and Applications written by Leonard Barolli and published by Springer. This book was released on 2018-10-18 with total page 815 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents on the latest research findings, and innovative research methods and development techniques related to the emerging areas of broadband and wireless computing from both theoretical and practical perspectives. Information networking is evolving rapidly with various kinds of networks with different characteristics emerging and being integrated into heterogeneous networks. As a result, a number of interconnection problems can occur at different levels of the communicating entities and communication networks’ hardware and software design. These networks need to manage an increasing usage demand, provide support for a significant number of services, guarantee their QoS, and optimize the network resources. The success of all-IP networking and wireless technology has changed the way of life for people around the world, and the advances in electronic integration and wireless communications will pave the way for access to the wireless networks on the fly. This in turn means that all electronic devices will be able to exchange the information with each other in a ubiquitous way whenever necessary.

Download or read book Intelligent Reflecting Surface For B5G 6G Wireless Networks written by Qingqing Wu and published by Springer Nature. This book was released on 2023-12-23 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides comprehensive insights into the theory, models, and unique characteristics of intelligent reflecting surface (IRS) and its appealing applications in wireless information and power transmission for B5G/6G. It is organized as follows: Chapter 1 gives an overview of the fundamentals of IRS, including the signal and channel models of IRS, its hardware architecture, advantages and practical constraints. Chapter 2, 3 and 4 focus on how to optimize the joint design of active and passive beamforming for three types of IRS-aided wireless information/energy transmission systems, namely IRS-aided power transfer (WPT), IRS-aided simultaneous wireless information and power transfer (SWIPT) and IRS-aided wireless powered communication networks (WPCN). Chapter 2 specifically presents a general framework design for IRS-aided WPT systems from the perspectives of energy beamforming design and channel estimation, while the dynamic IRS beamforming design is also discussed. Chapter 3 thoroughly studies the IRS-aided SWIPT for achieving better R-E trade-off, wherein two different designs based on weighted sum-power maximization at energy users (EUs) and under individual quality-of-service (QoS), requirements at both information users (IUs) and EUs are investigated. Chapter 4 presents three paradigms of IRS-aided WPCN, i.e., IRS-aided half-duplex (HD) WPCN, IRS-aided full-duplex (FD) WCPN and IRS-aided multiple-input-multiple-output (MIMO) FD WPCN. The authors present some related emerging topics, e.g., active IRS aided wireless communications and IRS-aided unmanned aerial vehicle (UAV) communications in chapter 5. This book targets postgraduate students studying electrical engineering and computer science, and can be used as a secondary textbook. Professionals, researchers and engineers working in wireless networks will also find this book useful as a reference.

Download or read book Resource Allocation in Next Generation Broadband Wireless Access Networks written by Singhal, Chetna and published by IGI Global. This book was released on 2017-02-14 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the growing popularity of wireless networks in recent years, the need to increase network capacity and efficiency has become more prominent in society. This has led to the development and implementation of heterogeneous networks. Resource Allocation in Next-Generation Broadband Wireless Access Networks is a comprehensive reference source for the latest scholarly research on upcoming 5G technologies for next generation mobile networks, examining the various features, solutions, and challenges associated with such advances. Highlighting relevant coverage across topics such as energy efficiency, user support, and adaptive multimedia services, this book is ideally designed for academics, professionals, graduate students, and professionals interested in novel research for wireless innovations.

Download or read book Resource Management Techniques for High Performance Ultra Widebrand Wireless Networks written by Yang Liu and published by Open Dissertation Press. This book was released on 2017-01-27 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Resource Management Techniques for High Performance Ultra Widebrand Wireless Networks" by Yang, Liu, 劉揚, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Abstract of thesis entitled "Resource Management Techniques for High Performance Ultra Wideband Wireless Networks" Submitted by LIU, Yang for the degree of Doctor of Philosophy at the University of Hong Kong in August 2006 Ultra wideband (UWB) short-range wireless communication systems are now widely envisioned as the key enabling technologies for high performance (i.e., high data rate and scalable) mobile computing applications such as real-time wireless video streaming, multiplayer wireless gaming, etc. However, many important resource management issues remain to be tackled before a UWB based wireless network can fully deliver its potential. Indeed, researchers have found that the applicability of existing resource management techniques designed for narrowband wireless systems or cellular networks for a UWB based environment is largely unknown. Specifically, a typical UWB physical layer design exhibits unique properties that do not exist in traditional wireless communication systems. As such, it becomes a new challenging problem to study the interplay of the UWB physical layer with the medium access control (MAC) layer in supporting quality-or-service (QoS) guaranteed applications. In this thesis, we have tackled five different resource management problems in UWB based networks. First, we observe that to provide adequate application layer QoS support, we must enhance the performance of the TCP layer so that it can fully exploit the high data rate provided by the underlying UWB based network. We propose a cross layer rate and power allocation algorithm based on the multilayer mode for a relatively small scale UWB mesh network. Second, in high density infrastructure networks, the fairness issue needs to be adequately addressed. Accordingly, we propose two new approaches in which the power level threshold used for handling the fairness parameter is dynamically adjusted for different traffic models. Third, we move on to consider ad hoc UWB based wireless networks. In such an environment, jointly optimizing the power level and data rate for each user becomes a difficult problem. We propose a practical optimization algorithm based on judicious power control for real-time applications and opportunistic scheduling for non-real-time applications in a small scale ad hoc network. In both scenarios, user specified QoS is guaranteed. Fourth, we consider the bandwidth scheduling problem in a UWB based hierarchical enterprise-scale ad hoc network. Based on mathematical analysis and computer simulations, it is demonstrated that our proposed scheduling scheme exhibits close-to-optimal performance governed by the proportional fairness (PF) constraint. Moreover, a novel self-organized clustering method is designed to improve system throughput while meeting the PF constraint. Finally, based on our practical clustering method with clusters connectivity guarantees, we propose an overlay network design for UWB enterprise-scale ad hoc networks. Results from an extensive simulation study indicate that our proposed techniques in all five problems are effective and outperform various existing approaches. (455 words) DOI: 10.5353/th_b3783410 Subjects: Ultra-wideband devices Broadband communication systems Wireless communication systems Scheduling Algorithms

Download or read book On Improving the Performance of Multihop Wireless Networks written by Yongning Zhang and published by . This book was released on 2008 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recently, wireless ad hoc networks have witnessed a remarkable interest. In such networks, the medium spatial reuse has a tremendous impact on the network performance, since it determines the number of concurrent transmissions and hence the network capacity. Although increasing spatial reuse can enhance the overall network performance, it raises the total interference level on the spectrum, therefore increasing the chance of collisions and adversely impacting the throughput. In this thesis, we optimize the network capacity of IEEE 802.11 based wireless networks through balancing the tradeoff between the level of spatial reuse and collisions in the network. We propose a dynamic spatiotemporal algorithm using the joint control of carrier sensing threshold and contention window size (both are tunable parameters) in order to enhance the spatial reuse and optimize the overall network throughput. In order to efficiently decide which protocol parameter(s) to tune, we deem it necessary to first faithfully distinguish among the causes of frame loss. We propose an effective loss differentiation mechanism to separate packet losses due to collisions from those due to interference(s) and establish accordingly appropriate reactive methods. Simulation results have demonstrated the significant throughput gains that can be achieved by the proposed scheme. We also present decentralized, localized heuristics in order to balance the tradeoff between exposed terminals and hidden terminals, through searching for the optimal transmission power and rate assignment (two other tunable parameters). Our simulation results indicate a remarkable performance for our proposed heuristics.

Download or read book Statistical Robust Beamforming for Broadcast Channels and Applications in Satellite Communication written by Andreas Gründinger and published by Springer Nature. This book was released on 2019-11-27 with total page 261 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book investigates adaptive physical-layer beamforming and resource allocation that ensure reliable data transmission in the multi-antenna broadcast channel. The book provides an overview of robust optimization techniques and modelling approximations to deal with stochastic performance metrics. One key contribution of the book is a closed-form description of the achievable rates with unlimited transmit power for a rank-one channel error model. Additionally, the book provides a concise duality framework to transform mean square error (MSE) based beamformer designs, e.g., quality of service and balancing optimizations, into equivalent uplink filter designs. For the algorithmic solution, the book analyses the following paradigm: transmission to receivers with large MSE targets (low demands) is switched off if the transmit power is low. The book also studies chance constrained optimizations for limiting the outage probability. In this context, the book provides two novel conservative outage probability approximations, that result in convex beamformer optimizations. To compensate for the remaining inaccuracy, the book introduces a post-processing power allocation. Finally, the book applies the introduced beamformer designs for SatCom, where interference from neighboring spotbeams and channel fading are the main limitations.

Download or read book Enhancing the Performance of Advanced Wireless Systems Via Passive Beamforming written by TIanxiang Li and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contemporary wireless networks are experiencing an era of unprecedented advancements, driven by the escalating demand from new wireless applications such as augmented and virtual reality, and further bolstered by the widespread deployment of the Internet of Things (IoT). These advancements encompass a range of technologies, comprising progress in wireless communication, wireless sensing, and wireless power transfer. mmWave technology is considered the key enabler of ultra-high data rates and capacity for future wireless communication, addressing the escalating demands of applications like high-definition video streaming and augmented reality. WiFi technology, the cornerstone of indoor wireless communications, has also undergone significant advancements in the various generations, offering higher throughput and network capacity. Meanwhile, the proliferation of wireless access points has sparked interest in harvesting power from Radio Frequency (RF) signals to power up the mass number of IoT devices. Despite these advancements in wireless technology, there remains a distinct disconnect between the evolution of wireless protocols and antenna hardware, with each failing to fully benefit from the progress of the other. In this thesis, we adopt a combined hardware-software co-design methodology to address the challenges of modern wireless networks, synergizing the latest developments in both wireless network protocols and antenna technology. In particular, we draw inspiration from the passive beamforming principle of Frequency Scanning Antenna (FSA), traditionally utilized in the field of radar and imaging, and integrate it in the field of wireless communication, sensing, and power transfer. In contrast to active beamforming technology, which uses intricate and energy-consuming electronic components to steer the beam, FSA utilizes the physical structure of the antenna to steer the beam based on signal frequency. We integrate this unique passive beamforming feature of FSA with wireless protocols to enhance the range and performance of future wireless systems. In this thesis, we first explore the challenges of modern-day wireless networks then discuss how we can address them using passive beamforming with FSA. A key challenge of mmWave networks is the significant signal attenuation due to high frequency. To compensate, base stations transmit mmWave signals using narrow beams that can be easily blocked by physical obstacles, greatly impacting their real-world deployment. In the first part of this work we propose mmXtend, a low-cost, low-power mmWave repeater that uses passive beamforming to provide high-data-rate links to a large number of users simultaneously in scenarios where the line-of-sight path is blocked. Following this, we explore the evolution of WiFi technology. Despite the advancements of WiFi protocol over the years, the performance of WiFi networks is still constrained by the inherent limitations of its antenna hardware design. Today's WiFi devices mainly use omni-directional antennas, which fail to capitalize on the advancements in WiFi protocols, and conversely, these protocols do not leverage the potential of antenna technologies. This disconnect markedly hampers the overall performance of WiFi systems. In the second part of this thesis, we introduce Wi-Pro, a plug-and-play module, which enhances WiFi performance by integrating passive beamforming with the WiFi protocol. It can be deployed on any WiFi device without requiring firmware or chipset modifications. Additionally, for wireless power transfer, although it has been a long-standing topic of discussion, its practical applications in the real world remain limited. The main barriers include the restricted range for energy transfer and the lack of an efficient, low-power method for beam alignment, which is essential for effective energy transfer. In the third part of this thesis, we introduce mmCharge, a mmWave power harvesting system which uses passive beamforming to increase the range of mmWave wireless power transfer. Our research shows that by integrating the concept of passive beamforming in the field of wireless communication, sensing, and power transfer, we can enhance performance and enable new capabilities. This thesis provides a comprehensive exploration into the development of end-to-end wireless systems that employ passive beamforming via FSA, which paves the way for future research in this area.

Download or read book Improving Next generation Wireless Network Performance and Reliability with Deep Learning written by Faris Bassam Mismar and published by . This book was released on 2019 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: A rudimentary question whether machine learning in general, or deep learning in particular, could add to the well-established field of wireless communications, which has been evolving for close to a century, is often raised. While the use of deep learning based methods is likely to help build intelligent wireless solutions, this use becomes particularly challenging for the lower layers in the wireless communication stack. The introduction of the fifth generation of wireless communications (5G) has triggered the demand for “network intelligence” to support its promises for very high data rates and extremely low latency. Consequently, 5G wireless operators are faced with the challenges of network complexity, diversification of services, and personalized user experience. Industry standards have created enablers (such as the network data analytics function), but these enablers focus on post-mortem analysis at higher stack layers and have a periodicity in the time scale of seconds (or larger). The goal of this dissertation is to show a solution for these challenges and how a data-driven approach using deep learning could add to the field of wireless communications. In particular, I propose intelligent predictive and prescriptive abilities to boost reliability and eliminate performance bottlenecks in 5G cellular networks and beyond, show contributions that justify the value of deep learning in wireless communications across several different layers, and offer in-depth analysis and comparisons with baselines and industry standards. First, to improve multi-antenna network reliability against wireless impairments with power control and interference coordination for both packetized voice and beamformed data bearers, I propose the use of a joint beamforming, power control, and interference coordination algorithm based on deep reinforcement learning. This algorithm uses a string of bits and logic operations to enable simultaneous actions to be performed by the reinforcement learning agent. Consequently, a joint reward function is also proposed. I compare the performance of my proposed algorithm with the brute force approach and show that similar performance is achievable but with faster run-time as the number of transmit antennas increases. Second, in enhancing the performance of coordinated multipoint, I propose the use of deep learning binary classification to learn a surrogate function to trigger a second transmission stream instead of depending on the popular signal to interference plus noise measurement quantity. This surrogate function improves the users' sum-rate through focusing on pre-logarithmic terms in the sum-rate formula, which have larger impact on this rate. Third, performance of band switching can be improved without the need for a full channel estimation. My proposal of using deep learning to classify the quality of two frequency bands prior to granting the band switching leads to a significant improvement in users' throughput. This is due to the elimination of the industry standard measurement gap requirement—a period of silence where no data is sent to the users so they could measure the frequency bands before switching. In this dissertation, a group of algorithms for wireless network performance and reliability for downlink are proposed. My results show that the introduction of user coordinates enhance the accuracy of the predictions made with deep learning. Also, the choice of signal to interference plus noise ratio as the optimization objective may not always be the best choice to improve user throughput rates. Further, exploiting the spatial correlation of channels in different frequency bands can improve certain network procedures without the need for perfect knowledge of the per-band channel state information. Hence, an understanding of these results help develop novel solutions to enhancing these wireless networks at a much smaller time scale compared to the industry standards today

Download or read book Optimization Techniques for Wireless Networks written by Jun Yuan and published by . This book was released on 2007 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wireless networking has emerged as an important area of research in the design of modern communications. Applications based on wireless networks span from ubiquitous voice communication to broadband wireless Internet and environment monitoring. As there is no "one size fits all" network, many different network architectures have been proposed in practice. Examples include the cellular architecture, the mesh architecture, and the ad hoc network architecture.This thesis provides an optimization framework for wireless network design. It puts the application needs as the optimization objective, and takes into account various design challenges across the network layers as optimization constraints. By adopting a "divide-and-conquer" strategy, this framework decomposes a complex optimization problem into several smaller subproblems, thus making efficient and distributed implementation possible.There are three main results in this thesis. First, we apply the optimization framework in wireless sensor network design by formulating a joint optimization of source coding, routing, and power allocation. Due to partial and correlated observations among the sensors, source coding distortion becomes a nonlinear and nonseparable function of all sensors' rates. We propose a novel source coding model, which allows efficient design of practical quantization schemes. We then present a dual algorithm, together with a technique called the column generation method, that allows an efficient solution for the overall sensor network design.Second, we address the throughput maximization problem in wireless mesh networks for broadband multimedia applications. In particular, we apply the optimization framework as a crosslayer strategy of joint multicast routing and interference management. We emphasize the network coding technique for multicast routing and a game theoretic method for interference management, for which efficient and distributed solutions are derived and illustrated.Third, we tackle the inter-cell interference problem in wireless cellular networks. We present efficient numerical solutions from either a (centralized) optimality perspective, or a (distributed) game theoretic perspective, or a combination of both. Our solutions dynamically balance the spectrum among multiple users with a taxation mechanism, and achieve significant improvement in spectral efficiency.

Download or read book Wireless Edge Caching written by Thang X. Vu and published by Cambridge University Press. This book was released on 2021-03-11 with total page 431 pages. Available in PDF, EPUB and Kindle. Book excerpt: Discover the latest research results for both uncoded and coded caching techniques in future wireless network design.