Author: Yu-Chia ChenPublisher:
ISBN:
Category :
Languages : en
Pages : 136
Book Description
Low Complexity Adaptive Semi-blind Space-time Block Code MIMO CDMA Receiver Design
New Low-Complexity Space-time Coded MIMO-CDMA System Design With Semi- Blind Channel Estimation in Multipath Channel
Author: 洪毓謙Low Complexity Space-Time Coding for MIMO Systems
Author: Amr IsmailPublisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
The last few years witnessed a dramatic increase in the demand on high-rate reliable wireless communications. In order to meet these new requirements, resorting to Multiple-Input Multiple-Output (MIMO) techniques was inevitable as they may offer high-rate reliable wireless communications without any additional bandwidth. In the case where the transmitter does not have any prior knowledge about the channel state information, space-time coding techniques have proved to efficiently exploit the MIMO channel degrees of freedom while taking advantage of the maximum diversity gain. On the other hand, the ML decoding complexity of Space-Time Codes (STCs) generally increases exponentially with the rate which imposes an important challenge to their incorporation in recent communications standards. Recognizing the importance of the low-complexity criterion in the STC design for practical considerations, this thesis focuses on the design of new low-complexity Space-Time Block Codes (STBCs) where the transmitted code matrix can be expressed as a weighted linear combination of information symbols and we propose new codes that are decoded with a lower complexity than that of their rivals in the literature while providing better or slightly lower performance.
MIMO-OFDM for LTE, WiFi and WiMAX
Author: Lajos HanzoPublisher: John Wiley & Sons
ISBN: 0470686693
Category : Technology & Engineering
Languages : en
Pages : 708
Book Description
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.
Quasi-orthogonal Space-time Block Code
Author: Chau YuenPublisher: Imperial College Press
ISBN: 1860948693
Category : Computers
Languages : en
Pages : 209
Book Description
Quasi-Orthogonal Space-Time Block Code presents an up-to-date, comprehensive and in-depth discussion of an important emerging class of space-time codes, called the Quasi-Orthogonal STBC (QO-STBC). Used in Multiple-Input Multiple-Output (MIMO) communication systems, they provide transmit diversity with higher code rates than the well-known orthogonal STBC (O-STBC), yet at lower decoding complexity than non-orthogonal STBC. This book will help readers gain a broad understanding of the fundamental principles as well as the state-of-the-art work in QO-STBC, thus enabling them to appreciate the roles of QO-STBC in future broadband wireless systems and to inspire further research. Sample Chapter(s). Foreword (151 KB). Chapter 1: Introduction of MIMO Channel and Space-Time Block Code (703 KB). Contents: Introduction of MIMO Channel and Space-Time Block Code; Orthogonal and Quasi- Orthogonal Space-Time Block Code; Insights of QO-STBC; Quasi-Orthogonal Space-Time Block Code with Minimum Decoding Complexity; Differential QO-STBC; Rate, Complexity and Diversity Trade-Off in QO-STBC; Other Developments and Applications of QO-STBC. Readership: Academics and graduate-level research students and developers of next-generation wireless systems.
Space-Time Block Coding for Wireless Communications
Author: Erik G. LarssonPublisher: Cambridge University Press
ISBN: 9780521065337
Category : Technology & Engineering
Languages : en
Pages : 304
Book Description
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.
Space-time Code Designs and Fast Decoding for MIMO and Cooperative Communication Systems
Author: Yue ShangPublisher: ProQuest
ISBN: 9780549924753
Category : MIMO systems
Languages : en
Pages :
Book Description
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.
A Study on Blind and Semiblind Detection for MIMO Systems and ARQ Retransmissions
Author: Muhammad ZiaPublisher:
ISBN: 9781124319124
Category :
Languages : en
Pages :
Book Description
We investigate blind and semi-blind channel estimation and detection techniques for multiple-input multiple-output (MIMO) communication systems. MIMO is an emerging technology that provides significant capacity and throughput gain over single-input single-output (SISO) systems without increase in bandwidth and power. To achieve these gains, typically, it requires pilot assisted channel estimation at the cost of bandwidth and power efficiency. Blind and semi-blind channel estimation or direct data detection techniques provide viable alternatives. We begin with blind zero-forcing (ZF) detection of Space-Time Block (STB) coded signal for MIMO systems over flat-fading channels for single user systems. We propose linear programming-based blind ZF equalization algorithm. Our method is globally convergent. We exploit redundancy and the implicit structure of space-time block codes to cast the problem into a low complexity linear programming. Unlikeseveral known methods, the proposed technique is applicable to full-rate space-time block codes such as the popular Alamouti orthogonal code and the quasi-orthogonal space time code. For orthogonal space-time codes, our LP algorithm achieves near maximum likelihood detection of orthogonal codes without channel knowledge and does not impose any conditions on the number of receive antennas. We extend this work to blind detection of STB coded data for co-channel synchronous multiuser MIMO system. We propose a globally convergent algorithm for the blind detection of co-channel multiuser signals under synchronous orthogonal space-time block coded modulation. We exploit the algebraic structure of the orthogonal space-time block codes and the Quadrature Amplitude Modulation (QAM) signal constellation to derive a quadratic programming (QP) algorithm that achieves desired convergence without the aid of training pilots. Focusing on the high rate space-time block codes in a synchronous co-channel multiuser system, we propose a successive processing strategy based on the proposed blind zero forcing (ZF) detector which has low computational complexity and fast convergence. Furthermore, our QP receiver for multiuser detection imposes less stringent conditions on the number of receive antennas of the multi-input-multi-output (MIMO) system. After investigating blind detection of STB coded signals for single and multiuser MIMO system, we focus on bandwidth and power efficient Hybrid Automatic Repeat reQuest (HARQ) at the physical layer level. The concept of HARQ is adapted in Long Term Evolution (LTE) and WiMAX standard and both standards consider full retransmission of the original copy of the original information. The physical layer performs joint detection called diversity combining. We propose retransmission of partial copy of original message and omit pilot symbols during retransmission. Our receiver jointly estimates channel of the both transmissions in semi-blind fashion. The joint detection of two transmissions improves overall performance of the receiver. We demonstrate bandwidth savings without significant performance loss and mild increase in complexity.
Efficient Signal, Code, and Receiver Designs for MIMO Communication Systems
Author: Huan YaoPublisher:
ISBN:
Category :
Languages : en
Pages : 205
Book Description
(Cont.) Finally, for the case where no channel knowledge is available, we present a geometric view of the signal design problem. This view reveals how training based approaches can achieve the optimal (non-coherent) diversity-multiplexing tradeoff.
Author: Amr Hussein El Mougy