Download or read book A Fast Sphere Decoding Algorithm for Rank Deficient MIMO Systems written by Ahmed Ahmed and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fast Sphere Decoder for MIMO Systems written by Praveen G. Krishnan and published by . This book was released on 2007 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This work focuses on variants of the conventional sphere decoding technique for Multi Input Multi Output (MIMO) systems. Space Time Block Codes (STBC) have emerged as a popular way of transmitting data over multiple antennas achieving the right balance between diversity and spatial multiplexing. The Maximum Likelihood (ML) technique is a conventional way of decoding the transmitted information from the received data, but at the cost of increased complexity. The sphere decoder algorithm is a sub-optimal decoding technique that is computationally efficient achieving a ;symbol error rate that is dependent on the initial radius of the sphere. In this thesis, the decreasing rate of the radius of the sphere is increased by using a scaling factor of less than unity. This allows the algorithm to examine less number of vectors compared to the original algorithm making it much more computationally efficient. The sphere decoding algorithm is largely focused on the Alamouti codes that have two antennas at the transmitter. This work extends the sphere decoding algorithm to other STBC having more than 2 transmit and receive antennas. The performance and the computational complexity of the fast sphere decoder is compared with that of the original sphere decoder and its variants"--Abstract, leaf iii
Download or read book Sphere decoding for Underdetermined Integer Least square Communications Problems written by Ping Wang (1978 Nov. 26-) and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "Underdetermined detection problems can arise in communications, e.g., multi-user detection for overloaded CDMA-based systems, MIMO systems with the number of receive antennas smaller than that of transmit antennas. They can be formulated as underdetermined integer least-square (ILS) problems, and many conventional suboptimal detection schemes lead to poor performance, whilst standard sphere-decoding (SD) algorithms, which can achieve optimal maximum-likelihood (ML) performance with low complexity for full-column-rank ILS systems, cannot be directly applied. The principal objective of this dissertation is to develop efficient detection algorithms based on SD for the underdetermined detection problems, which can approach the optimal performance. Most of Generalized SD (GSD) algorithms, recently proposed to solve undetermined ILS problems, have to transform an M-QAM constellation (with M>4) into multiple QPSKs, and hence result in unfavorably enlarged problem size and increased complexity. In contrast, this dissertation proposes a GSD algorithm (called lambda-GSD) by transforming the underdetermined system into a full-column-rank one and then utilizing SD algorithm on the transformed problem, which can circumvent the problematic size increase for high QAMs. As a result, the proposed lambda-GSD algorithm keeps the original problem size for all modulation constellations and the efficiency is considerably improved for M-QAM (with M>4). We perform union-bound performance analysis and derive the criterion to choose the design parameter lambda. The performance analysis shows that lambda-GSD can provide the exact optimum ML performance for constant-modulus constellations and an ML-approaching performance for non-constant-modulus constellations by judiciously choosing lambda. Theoretical complexity study is an important and challenging issue for an algorithm. By exploiting the underlying transformed matrix structure, we derive closed-form formulas to approximate the expected complexity of lambda-GSD for various modulation types. A lower bound on the expected complexity exponent is also analytically established. The consistency between the theoretical and simulation results on the number of searching FLOPS indicates that the analytical complexity formulas can capture the key complexity characteristics of the proposed lambda-GSD algorithm and can also serve as references for other GSD algorithms. To speed up the searching, we consider two following aspects. One is to propose an improved lambda-GSD version that alleviates the possible ill-conditioned transformed structure by a systematic method to choose lambda. The other is to develop efficient radius setting strategies. A linear-programming approach is used to calculate the initial radius for hard-decision SD and GSD; and a radius updating strategy combined with a simple initial radius setting is developed for soft-output list-sphere-decoding (LSD) and list-generalized-sphere-decoding (LGSD) algorithms, which reduces greatly the searching complexity as compared to the fixed radius setting strategy."--
Download or read book On Designs and Fast Decoding Algorithms of Space time Codes and Group Codes written by Terasan Niyomsataya and published by . This book was released on 2008 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Space time Code Designs and Fast Decoding for MIMO and Cooperative Communication Systems written by Yue Shang and published by ProQuest. This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Space-time coding is an attractive technique to exploit the transmit diversity gain provided by a multiple-input multiple-output (MIMO) wireless system. Regarding a space-time code design, some important concerns are high rates, full diversity, large coding gain (diversity products) and low decoding complexity. However, a tradeoff exists among these goals and constructing a good code that optimizes some or all of these goals is a very practical and interesting problem that has attracted a lot of attention in the past 10 years. Furthermore, other design issues may also matter and should be taken into account when one considers certain special scenarios to which the space-time coding technique is applied. In this dissertation, we study both the code design at the transmitter side and the fast decoding algorithm at the receiver side for space-time coding. The first topic attempts to achieve both low decoding overhead and maximum (full) diversity for space-time block codes (STBC). By deploying a linear detector at the receiver, we can efficiently reduce the decoding complexity for an STBC and always obtain soft outputs that are desired when the STBC is concatenated with a channel code as in a real system. In this dissertation, we propose a design criterion for STBC to achieve full diversity with a zero-forcing (ZF) or minimum mean-square error (MMSE) receiver. Two families of STBC, orthogonal STBC (OSTBC) and Toeplitz codes, which are known to have full diversity with ZF or MMSE receiver, indeed meet this criterion, as one may expect. We also show that the symbol rates of STBC under this criterion are upper bounded by 1. Subsequently, we propose a novel family of STBC that satisfy the criterion and thus achieve full diversity with ZF or MMSE receiver. Our newly proposed STBC are constructed by overlapping the 2 x 2 Alamouti code and hence are named overlapped Alamouti codes. The new codes are close to orthogonal and have asymptotically optimal symbol rates. Simulation results show that overlapped Alamouti codes significantly outperform Toeplitz codes for any number of transmit antennas and also outperform OSTBC when the number of transmit antennas is above 4. The second topic concerns the design of space-time trellis codes (STTC) for their applications in cooperative communication systems, where transmission among different relay nodes that cooperate with each other is essentially asynchronous. A family of STTC that can achieve full cooperative diversity order regardless of the node transmission delays has been proposed and it was shown that the construction of this STTC family can be reduced to the design of binary matrices that can keep full row rank no matter how their rows are shifted. We call such matrices as shift-full-rank (SFR) matrices. We propose a systematic method to construct all the SFR matrices and, in particular, the shortest (square) SFR (SSFR) matrices that are attractive as the associated STTC require the fewest memories and hence the lowest decoding complexity. By relaxing the restriction imposed on SFR matrices, we also propose two matrix variations, q -SFR and LT-SFR matrices. In an extended cooperative system model with fractional symbol delays whose maximum value is specified, the STTC generated from q -SFR and LT-SFR matrices can still achieve asynchronous full diversity. As a result, more eligible generator matrices than SFR ones become available and some better STTC in terms of coding gain may be found. Finally, the third topic is to speed up the decoding algorithm for the vertical Bell Laboratories layered space-time (V-BLAST) scheme, a full rate STBC that however does not exploit any transmit diversity gain. A fast recursive algorithm for V-BLAST with the optimal ordered successive interference cancellation (SIC) detection has been proposed and two improved algorithms for it have also been independently introduced by different authors lately. We first incorporate the existing improvements into the original fast recursive algorithm to give an algorithm that is the fastest known one for the optimal SIC detection of V-BLAST. Then, we propose a further improvement from which two new algorithms result. Relative to the fastest known one from the existing improvements, one new algorithm has a speedup of 1:3 times in both the number of multiplications and the number of additions, and the other new algorithm requires less memory storage.
Download or read book Low Complexity MIMO Detection written by Lin Bai and published by Springer Science & Business Media. This book was released on 2012-01-07 with total page 251 pages. Available in PDF, EPUB and Kindle. Book excerpt: Low Complexity MIMO Detection introduces the principle of MIMO systems and signal detection via MIMO channels. This book systematically introduces the symbol detection in MIMO systems. Includes the fundamental knowledge of MIMO detection and recent research outcomes for low complexity MIMO detection.
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 Channel Estimation for Physical Layer Network Coding Systems written by Feifei Gao and published by Springer. This book was released on 2014-10-15 with total page 85 pages. Available in PDF, EPUB and Kindle. Book excerpt: This SpringerBrief presents channel estimation strategies for the physical later network coding (PLNC) systems. Along with a review of PLNC architectures, this brief examines new challenges brought by the special structure of bi-directional two-hop transmissions that are different from the traditional point-to-point systems and unidirectional relay systems. The authors discuss the channel estimation strategies over typical fading scenarios, including frequency flat fading, frequency selective fading and time selective fading, as well as future research directions. Chapters explore the performance of the channel estimation strategy and optimal structure of training sequences for each scenario. Besides the analysis of channel estimation strategies, the book also points out the necessity of revisiting other signal processing issues for the PLNC system. Channel Estimation of Physical Layer Network Coding Systems is a valuable resource for researchers and professionals working in wireless communications and networks. Advanced-level students studying computer science and electrical engineering will also find the content helpful.
Download or read book Space Time Coding written by Hamid Jafarkhani and published by Cambridge University Press. This book was released on 2005-09-22 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers the fundamental principles of space-time coding for wireless communications over multiple-input multiple-output (MIMO) channels, and sets out practical coding methods for achieving the performance improvements predicted by the theory. Starting with background material on wireless communications and the capacity of MIMO channels, the book then reviews design criteria for space-time codes. A detailed treatment of the theory behind space-time block codes then leads on to an in-depth discussion of space-time trellis codes. The book continues with discussion of differential space-time modulation, BLAST and some other space-time processing methods and the final chapter addresses additional topics in space-time coding. The theory and practice sections can be used independently of each other. Written by one of the inventors of space-time block coding, this book is ideal for a graduate student familiar with the basics of digital communications, and for engineers implementing the theory in real systems.
Download or read book MIMO Transceiver Design Via Majorization Theory written by Daniel P. Palomar and published by Now Publishers Inc. This book was released on 2007 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: MIMO Transceiver Design via Majorization Theory presents an up-to-date unified mathematical framework for the design of point-to-point MIMO transceivers with channel state information (CSI) at both sides of the link according to an arbitrary cost function as a measure of the system performance.
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 2012-01-03 with total page 693 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 Space Time Block Coding for Wireless Communications written by Erik G. Larsson and published by Cambridge University Press. This book was released on 2008-06-12 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt: Space-time coding is a technique that promises greatly improved performance in wireless networks by using multiple antennas at the transmitter and receiver. Space-Time Block Coding for Wireless Communications is an introduction to the theory of this technology. The authors develop the topic using a unified framework and cover a variety of topics ranging from information theory to performance analysis and state-of-the-art space-time coding methods for both flat and frequency-selective fading multiple-antenna channels. The authors concentrate on key principles rather than specific practical applications, and present the material in a concise and accessible manner. Their treatment reviews the fundamental aspects of multiple-input, multiple output communication theory, and guides the reader through a number of topics at the forefront of current research and development. The book includes homework exercises and is aimed at graduate students and researchers working on wireless communications, as well as practitioners in the wireless industry.
Download or read book The LLL Algorithm written by Phong Q. Nguyen and published by Springer Science & Business Media. This book was released on 2009-12-02 with total page 503 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first book to offer a comprehensive view of the LLL algorithm, this text surveys computational aspects of Euclidean lattices and their main applications. It includes many detailed motivations, explanations and examples.
Download or read book Coding Theory written by Andre Neubauer and published by John Wiley & Sons. This book was released on 2007-10-22 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the most important key technologies for digital communication systems as well as storage media is coding theory. It provides a means to transmit information across time and space over noisy and unreliable communication channels. Coding Theory: Algorithms, Architectures and Applications provides a concise overview of channel coding theory and practice, as well as the accompanying signal processing architectures. The book is unique in presenting algorithms, architectures, and applications of coding theory in a unified framework. It covers the basics of coding theory before moving on to discuss algebraic linear block and cyclic codes, turbo codes and low density parity check codes and space-time codes. Coding Theory provides algorithms and architectures used for implementing coding and decoding strategies as well as coding schemes used in practice especially in communication systems. Feature of the book include: Unique presentation-like style for summarising main aspects Practical issues for implementation of coding techniques Sound theoretical approach to practical, relevant coding methodologies Covers standard coding schemes such as block and convolutional codes, coding schemes such as Turbo and LDPC codes, and space time codes currently in research, all covered in a common framework with respect to their applications. This book is ideal for postgraduate and undergraduate students of communication and information engineering, as well as computer science students. It will also be of use to engineers working in the industry who want to know more about the theoretical basics of coding theory and their application in currently relevant communication systems
Download or read book Large MIMO Systems written by A. Chockalingam and published by Cambridge University Press. This book was released on 2014-02-06 with total page 335 pages. Available in PDF, EPUB and Kindle. Book excerpt: This exclusive coverage of the opportunities, technological challenges, solutions, and state of the art of large MIMO systems provides an in-depth discussion of algorithms for large MIMO signal processing, suited for large MIMO signal detection, precoding and LDPC code designs. An ideal resource for researchers, designers, developers and practitioners in wireless communications.
Download or read book MIMO Wireless Communications written by Claude Oestges and published by Academic Press. This book was released on 2010-07-27 with total page 477 pages. Available in PDF, EPUB and Kindle. Book excerpt: Uniquely, this book proposes robust space-time code designs for real-world wireless channels. Through a unified framework, it emphasizes how propagation mechanisms such as space-time frequency correlations and coherent components impact the MIMO system performance under realistic power constraints. Combining a solid mathematical analysis with a physical and intuitive approach to space-time coding, the book progressively derives innovative designs, taking into consideration that MIMO channels are often far from ideal.The various chapters of this book provide an essential, complete and refreshing insight into the performance behaviour of space-time codes in realistic scenarios and constitute an ideal source of the latest developments in MIMO propagation and space-time coding for researchers, R&D engineers and graduate students.Features include• Physical models and analytical representations of MIMO propagation channels, highlighting the strengths and weaknesses of various models• Overview of space-time coding techniques, covering both classical and more recent schemes under information theory and error probability perspectives• In-depth presentation of how real-world propagation affects the capacity and the error performance of MIMO transmission schemes• Innovative and practical designs of robust space-time coding, precoding and antenna selection techniques for realistic propagation (including single-carrier and MIMO-OFDM transmissions)"This book offers important insights into how space-time coding can be tailored for real-world MIMO channels. The discussion of MIMO propagation models is also intuitive and well-developed."Arogyaswami J. Paulraj, Professor, Stanford University, CA"Finally a book devoted to MIMO from a new perspective that bridges the boundaries between propagation, channel modeling, signal processing and space-time coding. It is of high reference value, combining intuitive and conceptual explanations with detailed, stringent derivations of basic facts of MIMO." Ernst Bonek, Emeritus Professor, Technische Universität Wien, Austria * Presents space-time coding techniques for real-world MIMO channels* Contains new design methodologies and criteria that guarantee the robustness of space-time coding in real life wireless communications applications* Evaluates the performance of space-time coding in real world conditions
Download or read book Fundamentals of Wireless Communication written by David Tse and published by Cambridge University Press. This book was released on 2005-05-26 with total page 598 pages. Available in PDF, EPUB and Kindle. Book excerpt: This textbook takes a unified view of the fundamentals of wireless communication and explains cutting-edge concepts in a simple and intuitive way. An abundant supply of exercises make it ideal for graduate courses in electrical and computer engineering and it will also be of great interest to practising engineers.
