Download or read book Interference Mitigation and Interference Avoidance for Cellular OFDMA TDD Networks written by Ellina Petrova Foutekova and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years, cellular systems based on orthogonal frequency division multiple access - time division duplex (OFDMA-TDD) have gained considerable popularity. Two of the major reasons for this are, on the one hand, that OFDMA enables the receiver to effectively cope with multipath propagation while keeping the complexity low. On the other hand, TDD offers efficient support for cell-specific uplink (UL)/downlink (DL) asymmetry demands by allowing each cell to independently set its UL/DL switching point (SP). However, cell-independent SP gives rise to crossed slots. In particular, crossed slots arise when neighbouring cells use the same slot in opposing link directions, resulting in base station (BS)-to-BS interference and mobile station (MS)-to-MS interference. BS-to-BS interference, in particular, can be quite detrimental due to the exposed location of BSs, which leads to high probability of line-of-sight (LOS) conditions. The aim of this thesis is to address the BS-to-BS interference problem in OFDMA-TDDcellular networks. A simulation-based approach is used to demonstrate the severity of BS-to-BS interference and a signal-to-interference-plus-noise ratio (SINR) equation for OFDMA is formulated to aid system performance analysis. The detrimental effects of crossed slot interference in OFDMA-TDD cellular networks are highlighted by comparing methods specifically targeting the crossed slots interference problem. In particular, the interference avoidance method fixed slot allocation (FSA) is compared against state of the art interference mitigation approaches, viz: random time slot opposing (RTSO) and zone division (ZD). The comparison is done based on Monte Carlo simulations and the main comparison metric is spectral efficiency calculated using the SINR equation formulated in this thesis. The simulation results demonstrate that when LOS conditions among BSs are present, both RTSO and ZD perform worse than FSA for all considered performance metrics. It is concluded from the results that current interference mitigation techniques do not offer an effective solution to the BS-to-BS interference problem. Hence, new interference avoidance methods, which unlike FSA, do not sacrifice the advantages of TDD are open research issues addressed in this thesis. The major contribution of this thesis is a novel cooperative resource balancing technique that offers a solution to the crossed slot problem. The novel concept, termed asymmetry balancing, is targeted towards next-generation cellular systems, envisaged to have ad hoc and multi-hop capabilities. Asymmetry balancing completely avoids crossed slots by keeping the TDD SPs synchronised among BSs. At the same time, the advantages of TDD are retained, which is enabled by introducing cooperation among the entities in the network. If a cell faces resource shortage in one link direction, while having free resources in the opposite link direction, the free resources can be used to support the overloaded link direction. In particular, traffic can be offloaded to near-by mobile stations at neighbouring cells that have available resources. To model the gains attained with asymmetry balancing, a mathematical framework is developed which is verified by Monte Carlo simulations. In addition, asymmetry balancing is compared against both ZD and FSA based on simulations and the results demonstrate the superior performance of asymmetry balancing. It can be concluded that the novel interference avoidance approach is a very promising candidate to.

Download or read book Scheduling Strategies and Interference Mitigation for OFDMA Cellular Networks written by Ashley Mills and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Interference Mitigation and Energy Management in 5G Heterogeneous Cellular Networks written by Yang, Chungang and published by IGI Global. This book was released on 2016-11-22 with total page 383 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years, wireless networks have become more ubiquitous and integrated into everyday life. As such, it is increasingly imperative to research new methods to boost cost-effectiveness for spectrum and energy efficiency. Interference Mitigation and Energy Management in 5G Heterogeneous Cellular Networks is a pivotal reference source for the latest research on emerging network architectures and mitigation technology to enhance cellular network performance and dependency. Featuring extensive coverage across a range of relevant perspectives and topics, such as interference alignment, resource allocation, and high-speed mobile environments, this book is ideally designed for engineers, professionals, practitioners, upper-level students, and academics seeking current research on interference and energy management for 5G heterogeneous cellular networks.

Download or read book Cooperation Strategies for Inter cell Interference Mitigation in OFDMA Systems written by Reben Kurda and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recently the use of modern cellular networks has drastically changed with the emerging Long Term Evolution Advanced (LTE-A) technology. Homogeneous networks which were initially designed for voice-centric and low data rates face unprecedented challenges for meeting the increasing traffic demands of high data-driven applications and their important quality of service requirements. Therefore, these networks are moving towards the so called Heterogeneous Networks (HetNets). HetNets represent a new paradigm for cellular networks as their nodes have different characteristics such as transmission power and radio frequency coverage area. Consequently, a HetNet shows completely different interference characteristics compared to homogeneous deployment and attention must be paid to these disparities when different tiers are collocated together. This is mostly due to the potential spectrum frequency reuse by the involved tiers in the HetNets. Hence, efficient inter-cell interference mitigation solutions in co-channel deployments of HetNets remain a challenge for both industry and academic researchers. This thesis focuses on LTE-A HetNet systems which are based on Orthogonal Frequency Division Multiplexing Access (OFDMA) modulation. Our aim is to investigate the aggressive interference issue that appears when different types of base stations are jointly deployed together and especially in two cases, namely Macro-Femtocells and Macro-Picocells co-existence. We propose new practical power adjustment solutions for managing inter-cell interference dynamically for both cases. In the first part dedicated to Femtocells and Macrocell coexistence, we design a MBS-assisted femtocell power adjustment strategy which takes into account femtocells users performance while mitigating the inter-cell interference on victim macrocell users. Further, we propose a new cooperative and context-aware interference mitigation method which is derived for realistic scenarios involving mobility of users and their varying locations. We proved numerically that the Femtocells are able to maintain their interference under a desirable threshold by adjusting their transmission power. Our strategies provide an efficient means for achieving the desired level of macrocell/femtocell throughput trade-off. In the second part of the studies where Picocells are deployed under the umbrella of the Macrocell, we paid a special attention and efforts to the interference management in the situation where Picocells are configured to set up a cell range expansion. We suggest a MBS-assisted collaborative scheme powered by an analytical model to predict the mobility of Macrocell users passing through the cell range expansion area of the picocell. Our goal is to adapt the muting ratio ruling the frequency resource partitioning between both tiers according to the mobility behavior of the range-expanded users, thereby providing an efficient trade-off between Macrocell and Picocell achievable throughputs.

Download or read book Performance Evaluation of Inter cell Interference Mitigation Techniques for OFDMA Cellular Networks written by Weiwei Wu and published by . This book was released on 2010 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Interference Mitigation for Two tier Heterogeneous Cellular Network and Dynamic Tdd Small Cell Network Via Limited Backhaul Cooperation written by 張原碩 and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Interference Mitigation in Device to Device Communications written by Masood Ur Rehman and published by John Wiley & Sons. This book was released on 2022-03-17 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: Explore this insightful foundational resource for academics and industry professionals dealing with the move toward intelligent devices and networks Interference Mitigation in Device-to-Device Communications delivers a thorough discussion of device-to-device (D2D) and machine-to-machine (M2M) communications as solutions to the proliferation of ever more data hungry devices being attached to wireless networks. The book explores the use of D2D and M2M technologies as a key enabling component of 5G networks. It brings together a multidisciplinary team of contributors in fields like wireless communications, signal processing, and antenna design. The distinguished editors have compiled a collection of resources that practically and accessibly address issues in the development, integration, and enhancement of D2D systems to create an interference-free network. This book explores the complications posed by the restriction of device form-factors and the co-location of several electronic components in a small space, as well as the proximity of legacy systems operating in similar frequency bands. Readers will also benefit from the inclusion of: A thorough introduction to device-to-device communication, including its history and development over the last decade, network architecture, standardization issues, and regulatory and licensing hurdles An exploration of interference mitigation in device-to-device communication underlaying LTE-A networks A rethinking of device-to-device interference mitigation, including discussions of the challenges posed by the proliferation of devices An analysis of user pairing for energy efficient device-to-device content dissemination Perfect for researchers, academics, and industry professionals working on 5G networks, Interference Mitigation in Device-to-Device Communications will also earn a place in the libraries of undergraduate, graduate, and PhD students conducting research into wireless communications and applications, as well as policy makers and communications industry regulators.

Download or read book QoE aware Inter cell Interference Mitigation for Dynamic TDD Networks written by 陳鈺杰 and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Interference Mitigation Techniques in Cellular OFDM Systems written by and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Study on Inter Cell Interference Mitigation Schemes for OFDMA Downlink Systems written by 邱哲盛 and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Co channel Interference Mitigation in Reuse 1 Cellular OFDM Systems written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Small Cell Networks written by Tony Q. S. Quek and published by Cambridge University Press. This book was released on 2013-05-02 with total page 441 pages. Available in PDF, EPUB and Kindle. Book excerpt: This comprehensive resource explores state-of-the-art advances in the successful deployment and operation of small cell networks. A broad range of technical challenges, and possible solutions, are addressed, including practical deployment considerations and interference management techniques, all set within the context of the most recent cutting-edge advances. Key aspects covered include 3GPP standardisation, applications of stochastic geometry, PHY techniques, MIMO techniques, handover and radio resource management, including techniques designed to make the best possible use of the available spectrum. Detailed technical information is provided throughout, with a consistent emphasis on real-world applications. Bringing together world-renowned experts from industry and academia, this is an indispensable volume for researchers, engineers and systems designers in the wireless communication industry.

Download or read book Avoiding Effects of OFDM Adjacent Channel Interference by Using Combinations of Modulation Schemes written by Le Tien Anh and published by GRIN Verlag. This book was released on 2009-05 with total page 89 pages. Available in PDF, EPUB and Kindle. Book excerpt: Master's Thesis from the year 2008 in the subject Engineering - Communication Technology, grade: erfolgreich bestanden, Keio University (Graduate school of Science and Technology - School of Science for Open and Environmental Systems), language: English, abstract: Non-orthogonality among adjacent OFDM channels creates OFDM adjacent channel interference and it heavily affects the entire system's performance. Conventional methods to avoid OFDM adjacent channel interference are not only insufficient but also are wasting a lot of frequency resources. In this research, a method using combinations of modulation schemes is proposed to avoid effects of OFDM adjacent channel interference. It can be obtained by modulating the sub-carriers at the outer sides of an OFDM channel with lower order modulation schemes (such as BPSK or QPSK), while modulating the sub-carriers at the inner side of the OFDM channel with higher order modulation schemes (such as 16QAM or 64QAM). Intensive simulations have been carried out to evaluate the performance of the proposed method. The simulation results have shown an increase in the OFDM system's resistance against adjacent channel interference while still maintain the bandwidth efficiency.

Download or read book Next Generation Mobile Access Technologies written by Harald Haas and published by Cambridge University Press. This book was released on 2008-01-10 with total page 403 pages. Available in PDF, EPUB and Kindle. Book excerpt: Future generations of wireless networks will place great demands on the performance of radio access technology. This book describes the features of various mobile access technologies and assesses their strengths and weaknesses. In particular, it describes the underlying principles and practical implementation schemes for time division duplexing (TDD). The book begins with an overview of next-generation wireless systems. It then describes the basics of duplex communication modes, interference in cellular systems, and multiple user access techniques. Focusing on TDD systems, dynamic channel assignment algorithms are discussed, as are multi-hop communications schemes, radio resource management, interference cancellation, and smart antennas. Real-world examples from UMTS, wireless LAN, and Bluetooth systems are described. The book is aimed at all those involved in the design and implementation of wireless systems, as well as at graduate students and researchers working in the area of wireless communications. For more information visit www.cambridge.org/9781107407794.

Download or read book LTE A Cellular Networks written by Abid Yahya and published by Springer. This book was released on 2016-09-02 with total page 131 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book, three different methods are presented to enhance the capacity and coverage area in LTE-A cellular networks. The scope involves the evaluation of the effect of the RN location in terms of capacity and the determination of the optimum location of the relay that provides maximum achievable data rate for users with limited interference at the cell boundaries. This book presents a new model to enhance both capacity and coverage area in LTE-A cellular network by determining the optimum location for the RN with limited interference. The new model is designed to enhance the capacity of the relay link by employing two antennas in RN. This design enables the relay link to absorb more users at cell edge regions. An algorithm called the Balance Power Algorithm (BPA) is developed to reduce MR power consumption. The book pertains to postgraduate students and researchers in wireless & mobile communications.

Download or read book Journal of Communications and Networks written by and published by . This book was released on 2008 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Evaluation of Interference Cancellation Architectures for Heterogeneous Cellular Networks written by Skander Kacem and published by . This book was released on 2013-07 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: Diploma Thesis from the year 2012 in the subject Engineering - Communication Technology, grade: excellent, Technical University of Berlin (Intelligent Networks), language: English, abstract: With the increasing data throughput requirements, the cellular network needs to move from homogeneous to heterogeneous system. In fact, the coexistence of different types of base stations with different capabilities such as femto/pico base stations as well as relays and macro base stations in random placements should improve the coverage and the spectral efficiency of the cellular networks. However, the complexity of inter-cell interference management will grow drastically and traditional interference avoidance/mitigation approaches need to be revised. Approaching this problem at the user equipment (UE), is of great interest since it can rely on little coordination among base stations. The work presented in this thesis focuses on a downlink interference cancellation at the UE and shows that such an intelligent receiver can bring its promised benefit only if the base stations get involved in the interference cancellation, specifically in the channel estimation process. The limitations of this approach are evaluated and depending on the surrounding base stations two solutions are proposed and discussed.