Download or read book High Rate Space Time Code with Linear Decoding Complexity for Multiple Transmitting Antennas written by Amir Laufer and published by . This book was released on 2012 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt: The multipath nature of the wireless channel, results in a superposition of the signals of each path at the receiver. This can lead to either constructive or destructive interference. Strong destructive interference is frequently referred to as deep fade and may result in temporary failure of communication due to the severe drop in the channel's signal-to-noise ratio (SNR). To avoid this situation, signal diversity might be introduced. When having more than one antenna at the transmitter and / or receiver, forming a Multiple-Input Multiple-Output (MIMO) channel, spatial diversity can be employed to overcome the fading problem. Space time block codes (STBC) have been shown to be used well with the MIMO channel. Each type of STBC is designed to optimize a different criteria such as rate and diversity, while other characteristics of the code are its error performance and decoding computational complexity. The Orthogonal STBC (OSTBC) family of codes is known to achieve full diversity as well as very simple implementation of the Maximum Likelihood (ML) decoder. However, it was proven that, with complex symbol constellation one cannot achieve a full rate code when the number of transmitting antennas is larger than two. Quasi OSTBC are codes with full rate but with the penalty of more complex decoding, and in general does not achieve full diversity. In this work, new techniques for OSTBC transmission / decoding are explored, such that a full rate code can be transmitted and decoded with linear complexity. The Row Elimination Method (REM) for OSTBC transmission is introduced, which basically involves the transmission of only part of the original OSTBC codeword, resulting in a full rate code termed Semi-Orthogonal STBC (SSTBC). Novel decoding scheme is presented, such that the SSTBC decoding computational complexity remains linear although the transmitted codeword is not orthogonal anymore. A new OSTBC, that complies with the new scheme's requirements, is presented for any number of transmit antennas. The performance of the new scheme is studied under various settings, such as system with limited feedback and multiple antennas at the receiver. The general decoding techniques presented for STBC, assume perfect channel knowledge at the receiver. It was shown, that the performance of any STBC system is severely degraded due to partial channel state information, results from imperfect channel estimation. To minimize the performance loss, one may lengthen the training sequences used for the channel estimation which, inevitably, results in some rate loss. In addition, complex decoding schemes can be used at the receiver to jointly decode the data while enhancing the channel estimation. It is suggested in this work to apply adaptive techniques to mitigate the performance loss without the penalty of additional rate loss or complex decoding. Namely, the bootstrap algorithm is used to further refine the received signals, resulting in better effective rate and performance in the presence of channel estimation errors. Modified implementations for the bootstrap's weights calculation method are also presented, to improve the convergence rate of the algorithm, as well as to maintain a very low computational burden.

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 Quasi orthogonal Space time Block Code written by Chau Yuen and published by Imperial College Press. This book was released on 2007 with total page 209 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Space Time Coding for Broadband Wireless Communications written by Georgios B. Giannakis and published by John Wiley & Sons. This book was released on 2007-02-26 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt: Eine vielversprechende Technologie zur Maximierung der Bandbreiteneffizienz in der breitbandigen drahtlosen Kommunikation ist die Raum-Zeit-Kodierung. Theorie und Praxis verbindend, ist dieses Buch die erste umfassende Diskussion von Grundlagen und designorientierten Aspekten von Raum-Zeit-Codes. Single-Carrier und Multi-Carrier-Übertragungen für Einzel- und Mehrnutzerkommunikation werden behandelt.

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 320 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 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 Distributed Space Time Coding written by Yindi Jing and published by Springer Science & Business Media. This book was released on 2013-04-23 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt: Distributed Space-Time Coding (DSTC) is a cooperative relaying scheme that enables high reliability in wireless networks. This brief presents the basic concept of DSTC, its achievable performance, generalizations, code design, and differential use. Recent results on training design and channel estimation for DSTC and the performance of training-based DSTC are also discussed.

Download or read book Space Time Coding for Large Antenna Arrays written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Multiple-input multiple-output (MIMO) systems can greatly improve the capacity and performance of wireless communications. In particular, space-time coding techniques have received much attention in recent years as an efficient approach to achieving the performance gains offered by MIMO channels. Thus far, most work on space-time coding has focused on systems with small antenna arrays or high signal-to-noise ratios (SNRs), for which it has been shown that codes should be designed according to the rank and determinant criteria. For such scenarios, coherent space-time coding and differential space-time modulation (DSTM) schemes have been designed, for systems with or without channel knowledge at the receiver, respectively. In recent years, there has been some work on coherent space-time coding for large arrays, which indicates that the code design metric should be chosen diffently from that for small arrays. In this dissertation, we study the design of space-time coding for large arrays. We focus on three aspects: performance analysis, code construction and decoding algorithms. We first analyze the asymptotic performance of differential space-time modulation. A new upper bound on the pairwise-error probability is derived for large arrays. This bound suggests that Euclidean distance is an appropriate design criterion for DSTM with large numbers of antennas, which is similar to the design of coherent space-time coding for the large-array regime. For two transmit antennas and four or more receive antennas, we use the new design criterion to obtain several new unitary codes with large minimum Euclidean distance. The proposed codes outperform some existing codes, for example, the well-known Alamouti code, for large receive arrays. Although the codes designed according to the new design criterion achieve good performance, most of them require maximum-likelihood (ML) decoding, which is undesirable for high-rate codes. On the other hand, the Alamouti code, which is designed f.

Download or read book PERFORMANCE ANALYSIS OF MIMO OFDM SYSTEM USING CODING AND EQUALIZATION written by G.KRISHNA REDDY and published by Archers & Elevators Publishing House. This book was released on with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Performance Analysis and Design of Space time Codes written by Chen Liao and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Wireless communication technologies have evolved from the original analog networks to IP-based network. Today's wireless communications have been affected by increasing customer expectations on wireless wideband internet services and continuously evolving improvements on technologies. Wireless communication systems must increase their ability to respond to the challenges. The new generation wireless systems (3G/4G) are designed for this purpose. The notable characteristic of 3G/4G is that it provides high data rate transmission at data rate up to 348kbps/2Mbps for 3G and 100Mbps/1Gbps for 4G. Designing the system for such high data rate transmission has become very challenging for wireless systems where the multipath fading is an important factor. In recent years, researches are ongoing in the industry and academic to increase capacity performance of wireless systems through antenna diversity. Multiple Input Multiple Output (MIMO) is one of the major recent developments in the study of high data rate transmission. There has been considerable attention paid to remarkable performance improvements in MIMO in terms of capacity. Another technology that has been traditionally adopted for wireless communications is the channel coding. Combining MIMO with channel coding has received increasing interest to support a variety of high data rate applications. These schemes have been termed as "space-time codes". Space-time codes are currently an area of exciting activity and have been studied as promising candidates for future 3G/4G systems. The most important characteristic of space-time codes is that it can provide full diversity gain as well as coding gain. In this dissertation, both performance analysis of upper bound of Pair-Wise Error Probability (PEP) and exact PEP are performed. In the derivation of exact PEP, a new method is presented. The method is straightforward and comprehensible. The upper bound provides the insight to understand the performance behavior for high Signal-to-Noise Ratio (SNR), while the exact PEP provides a better understanding of the performance behavior to other range of SNR. Design criteria for space-time codes had been first developed by Tarokh, which utilize the analysis of the upper bound on PEP to maximize diversity gain and coding gain from the property of the codeword distance matrix. These criteria are the most widely accepted, which form the basis for space-time codes. The criteria assume that the performance of space-time codes is dominated by the dominant error events. However, there are no dominant error events in fading channel for space-time codes. Therefore, Tarokh's criteria do not provide design guideline for the coding gain. Union bound analysis offers a alternative solution to this problem. The union bound technique is a more attractive method that allows us to analyze the contribution of all error events to the performance. In this thesis, the performance of space-time codes are analyzed using union bound analysis. Based on the union bound on Frame Error Rate (FER), new design criteria are proposed. This is achieved by applying more accurate upper bound of PEP in the union bound analysis. With the proposed criteria, new coding gain performance metrics had been defined. New codes based on the new performance metrics are designed and their coding gain performance superiority are demonstrated. Space-time block codes have been initially designed to provide full diversity order with low decoding complexity, but without coding gain. By integrating space-time trellis codes with space-time block codes, super-orthogonal space-time trellis codes can significantly enhance the coding gain performance. However, the super-orthogonal space-time trellis codes improve performance only in slow fading channel, but do not perform well in fast fading channel. In fast fading channel, the orthogonal design of space-time block codes has little effect on the coding gain and does not lead to noticeable improvement. Furthermore, super-orthogonal space-time trellis codes introduce the diversity gain loss in fast fading channel. It is well known that the performances of space-time codes are dominated by diversity gain and any diversity gain loss may cause substantial loss in performance. We therefore develop orthogonal space-time trellis codes, which improve performance in diversity gain in fast fading channel. The improvement is achieved by transferring the vector output of space-time trellis codes into an orthogonal matrix of space-time block codes, and meanwhile maintaining the symbol Hamming distance of space-time trellis codes. Theoretical analysis and simulation results had demonstrated that the proposed codes can improve diversity gain linearly with an increase in the number of transmit antennas. Performance saturation and decoding complexity increase with the increased number of trellis states are the major problems that trellis-based codes have to face in practice. Turbo codes that allow for reaching near Shannon limit performance are a significant advance in digital communications. Space-time turbo codes have been developed to achieve high performance. In a perfect world, system designers would like to achieve high performance while maintaining a full code rate. Therefore, puncture operation is always used in space-time turbo codes. The problem with the puncture operation in space-time turbo codes is that codeword distance matrix is rank deficient for small diversity gain in slow fading channel, which constitutes a major problem with space-time turbo codes. Space-time turbo codes that concern the rank deficiency have been developed. The codes improve performance by reducing the effect of rank deficiency on performance, but exist high complexity in both code structure and design criteria. This limitation makes the codes not suitable for the design of complex codes with large trellis state and/or large numbers of transmit antennas. A new space-time turbo codes have been proposed in this research. In previous works, it has been demonstrated the systematic structure with the rotation of the output of the low constitute encoder can effectively reduce the rank deficient effect on performance. Our new codes utilize the systematic characteristic to construct a simple code structure. Further, a simple but very effective trace criterion has been proposed. With the simple codes structure and design criteria, the design of complex codes can be achieved with significant improvement in coding gain performance for the systems with small diversity gain in slow fading channel. Overall, this dissertation presents new design criteria and new codes that contribute to improving performances of space-time codes.

Download or read book Space Time Coding written by Branka Vucetic and published by John Wiley & Sons. This book was released on 2003-06-02 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt: The capacity of wireless data communications is lagging behind demands due to unsatisfactory performance of the existing wireless networks, such as low data rates, low spectral efficiency and low quality of service. Space-time coding is an effective transmit diversity technique to combat fading in wireless communications. Space-time codes are a highly bandwidth-efficient approach to signalling within wireless communication that takes advantage of the spatial dimension by transmitting a number of data streams using multiple co-located antennas. There are various approaches to the coding structures, including space-time trellis coded modulation, space-time turbo codes and also layered architectures. The central issue in all these various coding structures is the exploitation of multipath effects in order to achieve very high spectral efficiencies. The spectral efficiencies of traditional wireless systems range between 1-5bps/sec/Hz but by using space-time techniques spectral efficiencies of 20-40bps/sec/Hz have been possible. Hence, space-time coding enables an increase in capacity by an order of magnitude. This is the main reason why space-time codes have been included in the standards for the third generation wireless communication systems and ultimately why Space-time Coding will be in great demand by individuals within industry and academia. The comprehensive understanding of space-time coding is essential in the implementation of 3G, and as the only title currently available, Space-Time Coding will be the standard text for Researchers, telecommunication engineers and network planners, academics and undergraduate/postgraduate students, telecommunications managers and consultants.

Download or read book High Speed Wireless Communications written by Jiangzhou Wang and published by Cambridge University Press. This book was released on 2008-10-02 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt: Analysing and designing reliable and fast wireless networks requires an understanding of the theory underpinning these systems and the engineering complexities of their implementation. This text describes the underlying principles and major applications of high-speed wireless technologies, with emphasis on ultra-wideband (UWB) wireless systems, 3G long term evolution, and 4G mobile networks. Key topics such as cross-layer optimization are discussed in detail and various forms of UWB, including multi-band OFDM UWB, are covered. Recent research developments are described before identifying the scope and direction for future research. The overlay problem (interference problem) in UWB is discussed, and the author aims to illustrate that OFDM is not the best wireless access technique for high speed transmission. Covering the latest technologies in the area, this book will be a valuable resource for graduate students of electrical and computer engineering as well as practitioners in the wireless communications industry.

Download or read book Algebraic Space time Block Codes with Manageable Complexity of Maximum likelihood Detection written by Ming-Yang Chen and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Multiple-input multiple-output (MIMO) wireless systems provide tremendous throughput and reliability gains by utilizing multiple antennas at the transmitters and receivers. As a result, numerous papers have addressed communication and signal-processing topics like space-time code design and signal detection theory. However, today's industry still faces problems with integrating MIMO into products owing to the implementation complexity. Management of complexity is therefore essential to realize the promise of MIMO technology. Previous research on designing space-time block codes was mostly concerned with maximizing transmit diversity and coding gains, and with achieving the optimal diversity-multiplexing trade-off. In contrast, this thesis aims at designing new transmission strategies that can be efficiently decoded while retaining or approaching the optimal performance. The first part of this thesis proposes a new set of rate-1 space-time block codes in systems with 2^n-transmit antennas. These designs achieve the full spatial diversity in quadrature amplitude modulation (QAM). Furthermore, the column vectors of each code matrix can be partitioned into two classes such that any two vectors from different classes are orthogonal. As a result, the maximum-likelihood (ML) detection can be implemented in reduced time complexity. For a system with four transmit antennas, the proposed encoders attain the optimal bit error rate (BER) in QAM without the necessity of extra modulation. These results will be extended to new rate-1 codes employing four transmit antennas for which the ML detection can be determined in linear time. These codes similarly achieve the full diversity in QAM, and moreover in 4M-phase-shift keying (4M-PSK), while the corresponding ML detection can be accomplished by independently decoding each symbol. The reduction in detection complexity simply necessitates an increment of 0.21 dB in the signal-to-noise ratio (SNR) for sustaining the same BER.

Download or read book Complexity Aspects in Near Capacity MIMO Detection Decoding written by Ernesto Zimmermann and published by Jörg Vogt Verlag. This book was released on 2007 with total page 207 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Analysis and Design of Communication Techniques in Spectrally Efficient Wireless Relaying Systems written by Jian Zhao and published by Logos Verlag Berlin GmbH. This book was released on 2010 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation studies the communication technologies in relaying systems with multiple antennas, especially in the multiple-input multiple-output (MIMO) two-way relaying systems. Both information-theoretic aspects and practical communication strategies are considered and analyzed. For the information-theoretic analysis, an analytical framework for the coverage of MIMO relaying systems based on an outage capacity criterion is proposed. For MIMO two-way relaying systems, different data combining schemes at the relay are compared based on their achievable rates. In addition, optimal time-division (TD) strategies for MIMO two-way decode-and-forward (DF) relaying systems are proposed and analyzed. When the optimal TD strategies are applied, the increase of the achievable rate regions in the system is significant compared to those using the equal TD strategy. For the practical transmission schemes, we propose the self-interference (SI) aided channel estimation and data detection schemes for the broadcast phase of two-way DF relaying systems. Such schemes exploit the SI in two-way DF relaying systems when the superposition coding (SPC) scheme is applied. When the network coding scheme is applied in two-way DF relaying systems, we propose an asymmetric data rate transmission scheme that utilizes the known data bits at the receivers. Such a scheme exploits the a priori known bits at the weak link receiver in the broadcast phase of two-way relaying systems.

Download or read book Space Time Block Coding for Multiple Antenna Systems written by Biljana Badic and published by Sudwestdeutscher Verlag Fur. This book was released on 2009-01 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt: The demand for mobile communication systems with high data rates has dramatically increased in recent years. New methods are necessary in order to satisfy this huge communications demand, exploiting the limited resources such as bandwidth and power as efficient as possible. MIMO systems with multiple antenna elements at both link ends are an efficient solution for future wireless communications systems as they provide high data rates by exploiting the spatial domain under the constraints of limited bandwidth and transmit power. "Space-Time Block Coding for Multiple Antenna Systems" is devoted to space-time coding, a MIMO transmit strategy which exploits transmit diversity and high reliability systems. The concept of space- time coding is explained in a systematic way including simulation examples. The book includes algorithm design and detailed performance study of space-time codes for multiple-antenna systems with and without channel state information at the transmitter. This valuable resource will appeal to graduate and postgraduate students, researchers and engineers involved in design and implementation of STC for MIMO systems.

Download or read book Space time Code Design for Wireless Communication Systems written by Xiaoyong Guo and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: It is well understood that MIMO technology could enhance the reliability of wireless communication and increase the channel capacity. The design of space-time code to explore the benefit provided by the multi-antenna systems is of key importance. This dissertation addresses several issues concerning the design of space-time code. The following is a brief description of these issues and our contributions. Cyclic division algebra (CDA) has been introduced as a means to construct full-rate nonvanishing determinant STBC (space-time block code), which achieves the diversity-multiplexing trade-off and has a very good performance. There are two steps to construct CDA-based nonvanishing determinant STBC: construction of a cyclic extension over [Special characters omitted.] (i) and finding a non-norm element. For the first step we proposed a new up-to-down construction method. With this new method we find a broad range of cyclic extensions over [Special characters omitted.] (i), which encompasses all the previous constructions. For the second step, we give new criteria for the non-norm element. Non-norm elements found by these new criteria have smaller absolute values, hence the resulted STBC has a better coding gain. The well-known design criteria for space-time code is proposed by Guey-Fitz-Bell-Kuo in 1996 and Tarokh-Seshadri-Calderbank in 1998. The derivation of the design criteria is based on the assumption that the received signals are decoded with an ML receiver. One important issue seems to be long ignored: there is no design criterion for space-time code decoded with suboptimal receivers. Only until recently that Zhang-Liu-Wong and Shang-Xia studied the full diversity codes with linear receivers. We address the issue in a much broader sense. We proposed a more general receiver structure called PIC (partial interference cancellation) group decoding. A PIC group decoding can be viewed as an intermediate decoding algorithm between linear decoding and ML decoding. It encompasses both linear decoding and ML decoding as its two extremes. We also derived a design criterion for space-time codes with PIC receivers to achieve full diversity. The full diversity criteria for codes with ML receivers and linear receivers are special cases of our new design criterion. In many applications, wireless communication devices are limited by size or hardware complexity to one antenna. Cooperative communication was introduced for communication networks with single-antenna nodes to exploit the multi-path diversity. In cooperative communications, a few nodes positioned between the source node and destination node are served as the relay nodes. One important problem for cooperative communication networks is the time-asynchronism among the relay nodes. We propose a distributed space-time coding scheme called distributed linear convolutional space-time code (DLC-STC) to address this problem. We also give systematic construction methods of DLC-STC which achieves full diversity without time synchronization among the relay nodes. Furthermore, we show that our proposed DLC-STC achieves full diversity even with suboptimal receivers such as ZF/MMSE receiver and DFE receiver.