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 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 Efficient VLSI Architectures for MIMO and Cryptography Systems written by Qingwei Li and published by . This book was released on 2008 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: Multiple-input multiple-output (MIMO) communication systems have recently been considered as one of the most significant technology breakthroughs for modern wireless communications, due to the higher spectral efficiency and improved link reliability. The sphere decoding algorithm (SDA) has been widely used for maximum likelihood (ML) detection in MIMO systems. It is of great interest to develop low-complexity and high-speed VLSI architectures for the MIMO sphere decoders. The first part of this dissertation is focused on the low-complexity and high-speed sphere decoder design for the MIMO systems. It includes the algorithms simplification, and transformations, hardware optimization and architecture development. Specifically, we propose the layered reordered K-Best sphere decoding algorithm and dynamic K-best sphere decoding algorithm, which can significantly improve the detection performance or reduce the hardware complexity. We also present the efficient K-Best sorting architecture, which greatly simplifies the sorting operation of the K-Best SDA. In addition, we introduce the early-pruning K-Best SD scheme, which eliminates the unlikely candidate at early decoding stages, thus saves computational complexity and power consumptions. For the conventional sphere decoder design, we develop the parallel and pipeline interleaved sphere decoder architecture, which considerably increases the decoding throughput with negligible extra complexity. Finally, we design the efficient radius and list updating units for the list sphere decoder, which increases the speed of obtaining the new radius and reduces the complexity for generating the new candidate list. The wireless communication technologies are widely used for the benefits of portability and flexibility. However, the wireless security is extremely important to protect the private and sensitive information since the communication medium, the airwave, is shared and open to the public. Cryptography is the most standard and efficient way for information protection. The second part of this thesis is thus dedicated to the high-speed and efficient architecture design for the cryptography systems including ECC and Tate pairing. We propose an efficient fast architecture for the ECC in Lopez-Dahab projective coordinates. Compared with the conventional point operation implementations, the point addition and doubling operations can be significantly accelerated with reasonable hardware overhead by applying parallel processing and hardware reusing. Moreover, we develop a complexity reduction scheme and an overlapped processing architecture for the Tate pairing in characteristic three. The proposed architecture can achieve over 2 times speedup compared with conventional sequential implementations for the Duursma-Lee and Kwon-BGOS algorithms.

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 A Complex K Best Sphere Decoder with Efficient Search Design for MIMO Systems written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Digital Human Modeling written by Vincent D. Duffy and published by Springer. This book was released on 2007-08-24 with total page 1083 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book constitutes the refereed proceedings of the First International Conference on Digital Human Modeling, DHM 2007, held in Beijing, China in July 2007. The papers thoroughly cover the thematic area of digital human modeling, addressing the following major topics: shape and movement modeling and anthropometry, building and applying virtual humans, medical and rehabilitation applications, as well as industrial and ergonomic applications.

Download or read book Near Capacity Multi Functional MIMO Systems written by Lajos Hanzo and published by John Wiley & Sons. This book was released on 2009-05-11 with total page 738 pages. Available in PDF, EPUB and Kindle. Book excerpt: Providing an all-encompassing self-contained treatment of Near-Capacity Multi-Functional MIMO Systems , the book starts by categorizing the family of Multiple-Input Multiple-Output (MIMO) schemes as diversity techniques, multiplexing schemes, multiple access arrangements and beam-forming techniques. Sophisticated coherent and low-complexity non-coherent MIMO receivers dispensing with channel estimation are considered in both classic and cooperation-aided scenarios. It is demonstrated that in the presence of correlated shadow-fading, cooperation-assisted systems may be expected to outperform their non-cooperative counterparts. The book contains a 100-page chapter on the unified treatment of all block codes in the context of high-flexibility, cutting-edge irregular Linear Dispersion Codes (LDC), which approach the MIMO-capacity. The majority of the book’s solutions are in the optimum sphere-packing frame-work. Sophisticated amalgam of five year’s near-capacity MIMO research Detailed examination of wireless landscape, including the fields of channel coding, spacetime coding and turbo detection techniques Novel tool of Extrinsic Information Transfer Charts (EXIT) used to address recent developments Material presented logically, allowing advanced readers to turn directly to any specific chapter of interest One of the only books to cover these subjects, giving equal weighting to each

Download or read book Rapid Prototyping of a Fixed complexity Sphere Decoder and Its Application to Iterative Decoding of Turbo MIMO Systems written by Luis Gonzaga Barbero Liñán and published by . This book was released on 2006 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Advanced Computer Architecture written by Junjie Wu and published by Springer. This book was released on 2014-07-21 with total page 265 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book constitutes the refereed proceedings of the 10th Annual Conference on Advanced Computer Architecture, ACA 2014, held in Shenyang, China, in August 2014. The 19 revised full papers presented were carefully reviewed and selected from 115 submissions. The papers are organized in topical sections on processors and circuits; high performance computing; GPUs and accelerators; cloud and data centers; energy and reliability; intelligence computing and mobile computing.

Download or read book Reduction of Decoding Complexity for MIMO Sphere Decoding QOSTBC and OSTBC Systems written by Luay Azzam and published by . This book was released on 2008 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Rapid Prototyping of a Fixed complexity Sphere Decoder and Its Application to Iterative Decoding of Turbo MIMO Systems written by Luis Gonzaga Barbero Liñán 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 Improved Complexity Reduced Detection for the MIMO System Based on Sphere Decoding with Gradient Search written by and published by . This book was released on 2023 with total page 0 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 Near capacity Sphere Decoder Based Detection Schemes for MIMO Wireless Communication Systems written by Goodwell Kapfunde and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book MIMO Systems written by Hossein Khaleghi Bizaki and published by BoD – Books on Demand. This book was released on 2011-04-04 with total page 504 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years, it was realized that the MIMO communication systems seems to be inevitable in accelerated evolution of high data rates applications due to their potential to dramatically increase the spectral efficiency and simultaneously sending individual information to the corresponding users in wireless systems. This book, intends to provide highlights of the current research topics in the field of MIMO system, to offer a snapshot of the recent advances and major issues faced today by the researchers in the MIMO related areas. The book is written by specialists working in universities and research centers all over the world to cover the fundamental principles and main advanced topics on high data rates wireless communications systems over MIMO channels. Moreover, the book has the advantage of providing a collection of applications that are completely independent and self-contained; thus, the interested reader can choose any chapter and skip to another without losing continuity.

Download or read book Robust Multiple input Multiple output Communications written by Songsri Sirianunpiboon and published by . This book was released on 2010 with total page 95 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Multiple antennas at both the transmitter and receiver is known as multiple-input multiple-output (MIMO) system. This has emerged as the most promising technique for improving the performance of wireless digital transmission systems as well as allowing higher data rates to be obtained for a given bandwidth. A consequence of the MIMO wireless communications revolution is that multipath scattering of the transmitted signal has moved from being a problem to being a valuable resource. This has happened to such extent that MIMO systems have come to rely on this resource. However, away from dense urban and indoor environments such as Australian rural and remote areas with wide open spaces and flat or smooth undulating terrain such rich scattering can be hard to find. This research seeks to develop MIMO schemes which will give robust and reliable perfor?mance in environments that can change rapidly from rich scattering environment to clear line of sight between transmitter and receiver. Wireless communications system which are robust to changing environment conditions are a particular important factor in military communication systems as well as for civilian emergency services. In this work, polarization is proposed as a source of diversity in wireless communications. Polarization diversity is particularly suited to the Australian rural and remote environment where wide open spaces and flat or smooth undulating terrain give rise to line of sight conditions between the transmitter and the receiver. The polarization diversity of transmitted signals is mostly preserved by the line-of-sight environment, presenting an opportunity for transmitter and receiver diversity techniques. Another aspect of the research presented here is the development of fast, fixed complexity, decoding algorithms for space-time codes that are robust to the changing transmission conditions. Reliable high rate transmission over the MIMO system can only be achieved through "space-time coding". The major drawback of a number of potentially useful space-time codes is the high computational complexity of the known decoding algorithms. This is particular true for a number of codes which are best suited to the exploitation of polarization diversity. The existing "fast" decoding algorithm for this decoding problem, the so-called sphere decoder, has performance which depends crucially on the channel conditions. When the channel is close to singular, that is, when the channel between the base station and terminal is close to pure line-of-sight, the sphere decoder defaults to an exhaustive search. If such conditions persist the communication system could be in outage purely due to computational overload. In this project we develop fast decoding algorithms which have fixed complexity across all channel conditions. In particular, we present the fastest known fixed complexity decoding algorithm for the Golden code, an important code used in the WiMax standard for fully mobile internet access"--P. iii.

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.