Download or read book Low Complexity Block Processing Algorithms for Robust Adaptive Channel Estimation in OFDM Systems written by Christian Rohde and published by . This book was released on 2013 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Adaptive Semiblind Channel Estimation for OFDM OQAM Systems written by Tianze Su and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "In this thesis, we propose and investigate novel adaptive semi-blind channel estimation algorithms for OFDM/OQAM systems. OFDM/OQAM is regarded as a promising alternative to conventional CP-OFDM for multi-carrier modulation since it can provide better spectrum efficiency, albeit at the price of increased complexity. We first formulate a general system model of an OFDM/OQAM transceiver. Based on this model, we review a recently proposed block based semi-blind channel estimation method for OFDM/OQAM systems, known as the sign covariance matrix (SCM) method. This method mainly exploits the higher-order statistical properties of the data at the receiver side but is not well-suited for applications to time-varying channels. Subsequently, to overcome the drawbacks of this block-based technique, we propose adaptive semi-blind channel estimation algorithms for application to OFDM/OQAM. The proposed algorithms consist of an adaptive SCM technique obtained through exponential recursive averaging, as well as several constant modulus algorithms (CMA) for recursive estimation. Although all the adaptive algorithms are designed to deal with time-varying channels, they can also be used for rapid channel acquisition in the case of static or slowly-varying channels. Furthermore, we explore the coherence bandwidth of the channel and make use of this concept to improve the estimation accuracy via a frequency averaging technique that can be combined with the adaptive SCM. Simulation results validate the efficacy of the proposed adaptive estimation algorithms over both time-invariant and varying channels, showing their robustness in terms of convergence speed, tracking capability and residual estimation error in steady-state. In particular, the CMA with recursive least squares (CMA-RLS) updating proves to be the most preferable due to its excellent trade-off between convergence rate and residual error level. The CMA-RLS also offers the best performance in tracking a time-varying channel. In addition, simulation experiments demonstrate the effectiveness of combining the frequency averaging technique with the proposed adaptive SCM algorithm." --
Download or read book Low complexity Algorithms for Channel Estimation in Optimised Pilot assisted Wireless OFDM Systems written by Eugene Golovins and published by . This book was released on 2009 with total page 227 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Channel Estimation Algorithms for OFDM in Interference Scenarios written by Farah Zaarour and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The scarcity of the radio spectrum and the increasing demand on bandwidth makes it vital to optimize the spectrum use. While a maximum efficiency should be attained, a minimal interference level should be maintained. OFDM has been selected as the modulation scheme in several wireless standards. Channel estimation is a fundamental task in OFDM and it becomes even more challenging in the presence of interference. In this thesis, our aim is to propose channel estimation algorithms for OFDM systems in the presence of interference, where conventional channel estimators designed for OFDM fail. First, we consider the cognitive radio environment and propose a novel channel estimation framework for fast time-varying channels in OFDM with NBI. This is accomplished through an expectation maximization (EM) based algorithm. This formulation allows us to obtain a closed-form expression for the estimation of the noise power. In this thesis, we are particularly interested in a very recent scheme of superimposed pilots for OFDM (DNSP). DNSP assures interference-free pilots at the expense of data interference. Seen the modernity of DNSP, a suitable receiver has to be designed to cope with its design. We first propose a low-complexity interference canceler (IC) for slow time-varying channels with DNSP. The performance of the proposed IC is guaranteed when the channel estimation error is small. As another contribution, we extend the design of the approximated IC for DNSP so as to take the channel estimation errors into account. Finally, we consider robust channel estimation which can be viewed as one of the perspectives of this thesis.
Download or read book Simplified Robust Adaptive Detection and Beamforming for Wireless Communications written by Ayman ElNashar and published by John Wiley & Sons. This book was released on 2018-06-11 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents an alternative and simplified approaches for the robust adaptive detection and beamforming in wireless communications. It adopts several systems models including DS/CDMA, OFDM/MIMO with antenna array, and general antenna arrays beamforming model. It presents and analyzes recently developed detection and beamforming algorithms with an emphasis on robustness. In addition, simplified and efficient robust adaptive detection and beamforming techniques are presented and compared with exiting techniques. Practical examples based on the above systems models are provided to exemplify the developed detectors and beamforming algorithms. Moreover, the developed techniques are implemented using MATLAB—and the relevant MATLAB scripts are provided to help the readers to develop and analyze the presented algorithms. em style="mso-bidi-font-style: normal;"Simplified Robust Adaptive Detection and Beamforming for Wireless Communications starts by introducing readers to adaptive signal processing and robust adaptive detection. It then goes on to cover Wireless Systems Models. The robust adaptive detectors and beamformers are implemented using the well-known algorithms including LMS, RLS, IQRD-RLS, RSD, BSCMA, CG, and SD. The robust detection and beamforming are derived based on the existing detectors/beamformers including MOE, PLIC, LCCMA, LCMV, MVDR, BSCMA, and MBER. The adopted cost functions include MSE, BER, CM, MV, and SINR/SNR.
Download or read book Wireless Communications written by Giorgio A. Vitetta and published by John Wiley & Sons. This book was released on 2013-03-29 with total page 849 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces the theoretical elements at the basis of various classes of algorithms commonly employed in the physical layer (and, in part, in MAC layer) of wireless communications systems. It focuses on single user systems, so ignoring multiple access techniques. Moreover, emphasis is put on single-input single-output (SISO) systems, although some relevant topics about multiple-input multiple-output (MIMO) systems are also illustrated. Comprehensive wireless specific guide to algorithmic techniques Provides a detailed analysis of channel equalization and channel coding for wireless applications Unique conceptual approach focusing in single user systems Covers algebraic decoding, modulation techniques, channel coding and channel equalisation
Download or read book Intelligent Multi Modal Data Processing written by Soham Sarkar and published by John Wiley & Sons. This book was released on 2021-04-06 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive review of the most recent applications of intelligent multi-modal data processing Intelligent Multi-Modal Data Processing contains a review of the most recent applications of data processing. The Editors and contributors – noted experts on the topic – offer a review of the new and challenging areas of multimedia data processing as well as state-of-the-art algorithms to solve the problems in an intelligent manner. The text provides a clear understanding of the real-life implementation of different statistical theories and explains how to implement various statistical theories. Intelligent Multi-Modal Data Processing is an authoritative guide for developing innovative research ideas for interdisciplinary research practices. Designed as a practical resource, the book contains tables to compare statistical analysis results of a novel technique to that of the state-of-the-art techniques and illustrations in the form of algorithms to establish a pre-processing and/or post-processing technique for model building. The book also contains images that show the efficiency of the algorithm on standard data set. This important book: Includes an in-depth analysis of the state-of-the-art applications of signal and data processing Contains contributions from noted experts in the field Offers information on hybrid differential evolution for optimal multilevel image thresholding Presents a fuzzy decision based multi-objective evolutionary method for video summarisation Written for students of technology and management, computer scientists and professionals in information technology, Intelligent Multi-Modal Data Processing brings together in one volume the range of multi-modal data processing.
Download or read book OFDM Interference Mitigation Algorithms with Application to DVB H written by Sili Lu and published by . This book was released on 2008 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: Orthogonal frequency-division multiplexing (OFDM) has gained an increased popularity over the last few years and has been adopted as the modulation scheme of choice for beyond 3G mobile communication systems. This is mainly due to its high robustness to time dispersion effects and its low implementation complexity. DVB-H is the latest development within the set of Digital Video Broadcasting (DVB) standards that use OFDM as a modulation scheme. DVB-H is required to operate under high mobility conditions resulting in significant Inter-Carrier Interference (ICI). Under these conditions, the conventional one-tap per subcarrier channel estimation and equalization scheme is suboptimal since it does not account for ICI effects due to channel time-variation within an OFDM symbol. To mitigate ICI, we propose in this dissertation a simplified hybrid frequency/time-domain channel estimation algorithm. In addition, we design a reduced-complexity Q -tap frequency-domain equalizer (FEQ) and enhance its performance by integrating it with joint channel and data estimation and an ICI-mitigating pilot/data placement scheme. We also investigate differential OFDM detection as a low-complexity alternative for coherent detection and test its performance in the presence of Doppler for DVB-H system. Furthermore, we extend our approach to multiple-input multiple-out (MIMO) OFDM systems. We design a novel embedded space-frequency block code (SFBC)-OFDM scheme that performs well under high Doppler. We also propose a novel standard-conformable Cyclic Delay Diversity (CDD) scheme and its associated channel estimation scheme for comb-type OFDM transmissions, which achieves the Cramer-Rao lower bound on channel estimation mean square error.
Download or read book Low complexity Iterative Channel Estimation and Detection Techniques for OFDM Systems written by 耿念 and published by . This book was released on 2011 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Academic Press Library in Signal Processing written by Fulvio Gini and published by Academic Press. This book was released on 2013-09-10 with total page 1389 pages. Available in PDF, EPUB and Kindle. Book excerpt: This second volume, edited and authored by world leading experts, gives a review of the principles, methods and techniques of important and emerging research topics and technologies in communications and radar engineering. With this reference source you will: Quickly grasp a new area of research Understand the underlying principles of a topic and its application Ascertain how a topic relates to other areas and learn of the research issues yet to be resolved Quick tutorial reviews of important and emerging topics of research in array and statistical signal processing Presents core principles and shows their application Reference content on core principles, technologies, algorithms and applications Comprehensive references to journal articles and other literature on which to build further, more specific and detailed knowledge Edited by leading people in the field who, through their reputation, have been able to commission experts to write on a particular topic
Download or read book Channel Estimation for OFDM in Fast Fading Channels written by Ping Wan and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The increasing demand for high data rate transmission over broadband radio channels has imposed significant challenges in wireless communications. Accurate channel estimation has a major impact onthe whole system performance. Specifically, reliable estimate of the channel state information (CSI) is more challenging for orthogonal frequency division multiplexing (OFDM) systems in doubly selective fading channels than for the slower fading channels over which OFDM has been deployed traditionally. With the help of a basis expansion model (BEM), a novel multivariate autoregressive (AR) process is developed to model the time evolution of the fast fading channel. Relying on pilot symbol aided modulation (PSAM), a novel Kalman smoothing algorithm based on a second-order dynamic model is exploited, where the mean square error (MSE) of the channel estimator is near to that of the optimal Wiener filter. To further improve the performance of channel estimation, a novellow-complexity iterative joint channel estimation and symbol detection procedure is developed for fast fading channels with a small number of pilots and low pilot power to achieve the bit errorrate (BER) performance close to when the CSI is known perfectly. The new channel estimation symbol detection technique is robust to variations of the radio channel from the design values and applicable to multiple modulation and coding types. By use of the extrinsic information transfer (EXIT) chart, we investigate the convergence behavior of the new algorithm and analyze the modulation, pilot density, and error correction code selection for good system performance for a given power level. The algorithms developed in this thesis improve the performance of the whole system requiring only low ratios of pilot to data for excellent performance in fast fading channels.
Download or read book MIMO OFDM for LTE WiFi and WiMAX written by Lajos Hanzo and published by John Wiley & Sons. This book was released on 2010-11-01 with total page 708 pages. Available in PDF, EPUB and Kindle. Book excerpt: MIMO-OFDM for LTE, WIFI and WIMAX: Coherent versus Non-Coherent and Cooperative Turbo-Transceivers provides an up-to-date portrayal of wireless transmission based on OFDM techniques augmented with Space-Time Block Codes (STBCs) and Spatial-Division Multiple Access (SDMA). The volume also offers an in-depth treatment of cutting-edge Cooperative Communications. This monograph collates the latest techniques in a number of specific design areas of turbo-detected MIMO-OFDM wireless systems. As a result a wide range of topical subjects are examined, including channel coding and multiuser detection (MUD), with a special emphasis on optimum maximum-likelihood (ML) MUDs, reduced-complexity genetic algorithm aided near-ML MUDs and sphere detection. The benefits of spreading codes as well as joint iterative channel and data estimation are only a few of the radical new features of the book. Also considered are the benefits of turbo and LDPC channel coding, the entire suite of known joint coding and modulation schemes, space-time coding as well as SDM/SDMA MIMOs within the context of various application examples. The book systematically converts the lessons of Shannon's information theory into design principles applicable to practical wireless systems; the depth of discussions increases towards the end of the book. Discusses many state-of-the-art topics important to today's wireless communications engineers. Includes numerous complete system design examples for the industrial practitioner. Offers a detailed portrayal of sphere detection. Based on over twenty years of research into OFDM in the context of various applications, subsequently presenting comprehensive bibliographies.
Download or read book Signal Processing Channel Estimation and Link Adaptation in MIMO OFDM Systems written by Jianjun Ran and published by Cuvillier Verlag. This book was released on 2008 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Intelligent Multi Modal Data Processing written by Soham Sarkar and published by John Wiley & Sons. This book was released on 2021-04-05 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive review of the most recent applications of intelligent multi-modal data processing Intelligent Multi-Modal Data Processing contains a review of the most recent applications of data processing. The Editors and contributors – noted experts on the topic – offer a review of the new and challenging areas of multimedia data processing as well as state-of-the-art algorithms to solve the problems in an intelligent manner. The text provides a clear understanding of the real-life implementation of different statistical theories and explains how to implement various statistical theories. Intelligent Multi-Modal Data Processing is an authoritative guide for developing innovative research ideas for interdisciplinary research practices. Designed as a practical resource, the book contains tables to compare statistical analysis results of a novel technique to that of the state-of-the-art techniques and illustrations in the form of algorithms to establish a pre-processing and/or post-processing technique for model building. The book also contains images that show the efficiency of the algorithm on standard data set. This important book: Includes an in-depth analysis of the state-of-the-art applications of signal and data processing Contains contributions from noted experts in the field Offers information on hybrid differential evolution for optimal multilevel image thresholding Presents a fuzzy decision based multi-objective evolutionary method for video summarisation Written for students of technology and management, computer scientists and professionals in information technology, Intelligent Multi-Modal Data Processing brings together in one volume the range of multi-modal data processing.
Download or read book Fuzzy Systems and Data MiningII written by S.-L. Sun and published by IOS Press. This book was released on 2016-11-24 with total page 652 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fuzzy systems and data mining are now an essential part of information technology and data management, with applications affecting every imaginable aspect of our daily lives. This book contains 81 selected papers from those accepted and presented at the 2nd international conference on Fuzzy Systems and Data Mining (FSDM2016), held in Macau, China, in December 2016. This annual conference focuses on 4 main groups of topics: fuzzy theory, algorithm and system; fuzzy applications; the interdisciplinary field of fuzzy logic and data mining; and data mining, and the event provided a forum where more than 100 qualified, high-level researchers and experts from over 20 countries, including 4 keynote speakers, gathered to create an important platform for researchers and engineers worldwide to engage in academic communication. All the papers collected here present original ideas, methods and results of general significance supported by clear reasoning and compelling evidence, and as such the book represents a valuable and wide ranging reference resource of interest to all those whose work involves fuzzy systems and data mining.
Download or read book Proceedings of the 6th International Conference on Advance Computing and Intelligent Engineering written by Bibudhendu Pati and published by Springer Nature. This book was released on 2022-09-21 with total page 686 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book gathers high-quality research papers presented at the 6th International Conference on Advanced Computing and Intelligent Engineering (ICACIE 2021) organized by Bhubaneswar Institute of Technology, Bhubaneswar, Odisha, India, during December 23–24, 2021. It includes sections describing technical advances and the latest research in the fields of computing and intelligent engineering. Intended for graduate students and researchers working in the disciplines of computer science and engineering, the proceedings also appeal to researchers in the field of electronics, as they cover hardware technologies and future communication technologies.
Download or read book Wireless Communications Over Rapidly Time Varying Channels written by Franz Hlawatsch and published by Academic Press. This book was released on 2011-05-04 with total page 457 pages. Available in PDF, EPUB and Kindle. Book excerpt: As a result of higher frequencies and increased user mobility, researchers and systems designers are shifting their focus from time-invariant models to channels that vary within a block. Wireless Communications Over Rapidly Time-Varying Channels explains the latest theoretical advances and practical methods to give an understanding of rapidly time varying channels, together with performance trade-offs and potential performance gains, providing the expertise to develop future wireless systems technology. As well as an overview of the issues of developing wireless systems using time-varying channels, the book gives extensive coverage to methods for estimating and equalizing rapidly time-varying channels, including a discussion of training data optimization, as well as providing models and transceiver methods for time-varying ultra-wideband channels. An introduction to time-varying channel models gives in a nutshell the important issues of developing wireless systems technology using time-varying channels Extensive coverage of methods for estimating and equalizing rapidly time-varying channels, including a discussion of training data optimization, enables development of high performance wireless systems Chapters on transceiver design for OFDM and receiver algorithms for MIMO communication channels over time-varying channels, with an emphasis on modern iterative turbo-style architectures, demonstrates how these important technologies can optimize future wireless systems
