Download or read book Reduction of Implementation Complexity in MIMO OFDM Decoding for V BLAST Architecture written by Tariq Nanji and published by . This book was released on 2010 with total page 67 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation documents alternative designs of the Zero Forcing decoding algorithm with Successive Interference Cancellation (ZF-SIC) for use in Vertical Bell Laboratories Layered Space Time Architecture (V-BLAST) Multiple Input Multiple Output (MIMO) Orthogonal Frequency Division Multiplexing (OFDM) systems, in an effort to reduce the computational complexity of the receiver. The development of a wireless platform utilizing this architecture intended for use in an indoor wireless multipath environment was created to analyze the multipath environment. This implementation is the result of efforts from several individuals within the CST group. My contributions are documented in this dissertation. In order to obtain channel state information (CSI), a training sequence is sent with each incoming frame. A pseudo-inverse operation is performed on the channel matrix and applied to each OFDM symbol that was received. Performing this operation on each tone and across each OFDM symbol is computationally inefficient in a MIMO configuration. If the number of pseudo-inverses can be reduced while maintaining acceptable levels of bit error, the processing time of each frame can be decreased. Traditionally, tests of the performance of ZF-SIC have been conducted with simulations modelling a multipath channel. In this thesis, CSI is observed using an open loop platform developed for MIMO-OFDM communications. The rate of change of the channel is observed for different multipath environments. The proposed methods of decoding require modifications to ZF-SIC. The suggested changes are only applicable to a MIMO OFDM based method of data transmission. The most effective method of reducing decoding complexity and maintaining an acceptable number of bit errors was observed to occur in the time domain rather than in the frequency domain. For selecting frames and averaging frames in the time domain it was determined that the optimal number of OFDM symbols per frame is 1932 and 174, respectively.

Download or read book A Study of MIMO Detection Algorithms in Wireless Communications written by Jie Liang and published by . This book was released on 2009 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Design and Performance Analysis of a Low Complexity MIMO OFDM System with Walsh Block Coding written by Amr Hussein El Mougy and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Algorithms and VLSI Implementations of MIMO Detection written by Ibrahim A. Bello and published by Springer Nature. This book was released on 2022-07-22 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a detailed overview of detection algorithms for multiple-input multiple-output (MIMO) communications systems focusing on their hardware realisation. The book begins by analysing the maximum likelihood detector, which provides the optimal bit error rate performance in an uncoded communications system. However, the maximum likelihood detector experiences a high complexity that scales exponentially with the number of antennas, which makes it impractical for real-time communications systems. The authors proceed to discuss lower-complexity detection algorithms such as zero-forcing, sphere decoding, and the K-best algorithm, with the aid of detailed algorithmic analysis and several MATLAB code examples. Furthermore, different design examples of MIMO detection algorithms and their hardware implementation results are presented and discussed. Finally, an ASIC design flow for implementing MIMO detection algorithms in hardware is provided, including the system simulation and modelling steps and register transfer level modelling using hardware description languages. Provides an overview of MIMO detection algorithms and discusses their corresponding hardware implementations in detail; Highlights architectural considerations of MIMO detectors in achieving low power consumption and high throughput; Discusses design tradeoffs that will guide readers’ efforts when implementing MIMO algorithms in hardware; Describes a broad range of implementations of different MIMO detectors, enabling readers to make informed design decisions based on their application requirements.

Download or read book Space time frequency Block Codes for MIMO OFDM in Next Generation Wireless Systems written by Min Zhang and published by . This book was released on 2010 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis the use of space-frequency block codes (SFBC) and space-time-frequency block codes (STFBC) in wireless systems are investigated. A variety of SFBC and STFBC schemes are proposed for particular propagation scenarios and system settings where each has its own advantages and disadvantages. The objective is to pro-pose coding strategies with improved flexibility, feasibility and spectral efficiency,and reduce the decoding complexity in an MIMO-OFDM system.

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 2011-07-05 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 Receiver Architectures for MIMO Wireless Communication Systems Based on V BLAST and Sphere Decoding Algorithms written by Foluwaso Olunkunle Tade and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Modern day technology aspires to always progress. This progression leads to a lot of research in any significant area of improvement. There is a growing amount of end-users in the wireless spectrum which has led to a need for improved bandwidth usage and BER values. In other words, new technologies which would increase the capacity of wireless systems are proving to be a crucial point of research in these modern times. Different combinations of multiuser receivers are evaluated to determine performance under normal working conditions by comparing their BER performance charts. Multiple input, multiple output (MIMO) systems are incorporated into the system to utilise the increased capacity rates achievable using the MIMO configuration. The effect of MIMO on the technologies associated with modern day technological standards such as CDMA and OFDM have been investigated due to the significant capacity potentials these technologies normally exhibit in a single antenna scenario. An in-depth comparison is established before comparison is made with a conventional maximum likelihood (ML) detector. The complexity of the ML detector makes its realization evaluated in such a manner to achieve the same or near ML solution but with lower computational complexity. This was achieved using a proposed modification of the Schnorr-Euchner Sphere decoding algorithm (SE-SDA). The proposed sphere decoder (P-SD) adopts a modification of the radius utilised in the SE-SDA to obtain a near ML solution at a much lower complexity compared to the conventional ML decoder. The P-SD was configured to work in different MIMO antenna configurations. The need for the highest possible data rates from the available limited spectrum led to my research into the multi-user detection scenario and MIMO.

Download or read book K Best Decoders for 5G Wireless Communication written by Mehnaz Rahman and published by Springer. This book was released on 2016-08-31 with total page 75 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book discusses new, efficient and hardware realizable algorithms that can attain the performance of beyond 5G wireless communication. The authors explain topics gradually, stepping from basic MIMO detection to optimized schemes for both hard and soft domain MIMO detection and also to the feasible VLSI implementation, scalable to any MIMO configuration (including massive MIMO, used in satellite/space communication). The techniques described in this book enable readers to implement real designs, with reduced computational complexity and improved performance.

Download or read book Low Complexity MIMO Detection written by Lin Bai and published by Springer Science & Business Media. This book was released on 2012-01-08 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 Low Power Emerging Wireless Technologies written by Reza Mahmoudi and published by CRC Press. This book was released on 2017-07-12 with total page 389 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advanced concepts for wireless communications offer a vision of technology that is embedded in our surroundings and practically invisible, but present whenever required. Although the use of deep submicron CMOS processes allows for an unprecedented degree of scaling in digital circuitry, it complicates the implementation and integration of traditional RF circuits. The requirement for long operating life under limited energy supply also poses severe design constraints, particularly in critical applications in commerce, healthcare, and security. These challenges call for innovative design solutions at the circuit and system levels. Low Power Emerging Wireless Technologies addresses the crucial scientific and technological challenges for the realization of fully integrated, highly efficient, and cost-effective solutions for emerging wireless applications. Get Insights from the Experts on Wireless Circuit Design The book features contributions by top international experts in wireless circuit design representing both industry and academia. They explore the state of the art in wireless communication for 3G and 4G cellular networks, millimeter-wave applications, wireless sensor networks, and wireless medical technologies. The emphasis is on low-power wireless applications, RF building blocks for wireless applications, and short-distance and beam steering. Topics covered include new opportunities in body area networks, medical implants, satellite communications, automobile radar detection, and wearable electronics. Exploit the Potential behind Emerging Green Wireless Technologies A must for anyone serious about future wireless technologies, this multidisciplinary book discusses the challenges of emerging power-efficient applications. Written for practicing engineers in the wireless communication field who have some experience in integrated circuits, it is also a valuable resource for graduate students.

Download or read book Data Detection for MIMO OFDM Systems with Reduced Complexity in a Frequency Selective Environment written by Nora Kraska and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Layered Space time Structure for MIMO OFDM Systems written by Jianxuan Du and published by . This book was released on 2005 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt: The low complexity of layered processing makes the layered structure a promising candidate for MIMO systems with a large number of transmit antennas and higher order modulation. For broadband systems, orthogonal frequency division multiplexing (OFDM) appears promising for its immunity against delay spread. In addition, OFDM is especially suitable for frequency selective MIMO systems since the introduction of orthogonal subcarriers makes system design and implementation as simple as those for flat fading channels. Therefore, the combination of layered structure with OFDM is a promising technique for high-speed wireless data transmission. The proposed research is focused on the layered structure for MIMO-OFDM systems, where several techniques are proposed for performance enhancement, namely, channel estimation based on subspace tracking, parallel detection of group-wise space-time codes by predictive soft interference cancellation, quasi-block diagonal low-density parity-check codes (LDPC) coding and statistical data rate allocation for layered systems. For MIMO-OFDM systems, rank reduction by some linear transform matrix is necessary for channel estimation. In the proposed research, we propose a channel estimation algorithm for MIMO-OFDM systems, which uses the optimum low-rank channel approximation obtained by tracking the frequency autocorrelation matrix of the channel response. Then parallel detection algorithm is proposed for a modified layered system with group-wise space-time coding, where the structure of particular component space-time code trellises is exploited using partial information from the Viterbi decoder of the simultaneously decoded interfering component codes. Next we incorporate the layered structure with LDPC to develop a quasi-block diagonal LDPC space-time structure. The lower triangular structure of the parity check matrix introduces correlation between layers. Each layer, as a part of the whole codeword, can be decoded while taking information from other undetected layers to improve the decoding performance. In the end, a modified layered structure is proposed where the layer detection order is fixed and the data rate for each layer is allocated based on the detection order and channel statistics. With Gaussian approximation of layer capacities, we derive the optimum data rate allocation.

Download or read book Design and Implementation of 3GPP LTE MIMO OFDM Baseband Processor with Reduced Complexity MIMO Detector and Precode Codebook Searcher written by 馬振翔 and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 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 Implementation and Analysis of OFDM and CDMA Based MIMO V BLAST for MUD Using ZF and MMSE written by Kishor G. Maradia and published by . This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of future wireless communication is to provide high quality wireless multimedia services so that data with high rate can be transmitted reliably. Recent information on theoretic research has shown that Multiple Input Multiple Output (MIMO) systems can achieve enormous spectral efficiency. The use of multiple antennas allows an independent channel to be created in the space and is the most interesting and promising wireless research area. The use of multiple antennas at both ends of a wireless link holds the potential to drastically improve the spectral efficiency and link reliability in future wireless communications systems. It seems to be a promising candidate for the next generation. In this paper, two techniques for the next 4G system -- OFDM and CDMA -- are compared with respect to their error performance in multiuser environment. The studies of both transmission techniques are performed for MIMO architecture. This paper provides a comparison of OFDM and CDMA-based MIMO technique.

Download or read book Massively Parallel Softcore Processors Fo Real time FPGA based MIMO Detection written by Xuezheng Chu and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The requirements for higher computational capacity and lower cost of future high end real-time Digital Signal Processing (DSP) applications are rapidly growing. As a promising technique in wireless communication systems, Multiple-Input Multiple-Output (MIMO) enables significant high data rate wireless transmission, but on the other hand requires significant computing capacity from the underlying platform to enable real-time computing. Modern MIMO base stations use hundreds of DSP processors to enable this computing requirements, the solution however is still limited in computing capacity, and is high in power consumption, resource cost and size. In addition, high data rate services from MIMO detectors require high performance detection algorithms. Whilst significant progress has been made, the computational complexity of the algorithms is still very high. The thesis solves this problem from both embedded implementation and algorithm perspectives. In this thesis, a high performance and area efficient Field Programmable Gate Array (FPGA) based Processor Element (FPE) architecture has been presented. FPE is designed for FPGA-based DSP, enabling a powerful mix of software programmability and hardware configurability by constructing heterogeneous networks of softcore processors. To verify the performance and efficiency of FPE, a massively parallel softcore processor architecture has been constructed for Fixed-Complexity Sphere Decoder (FSD) MIMO, the resulting architecture enables real-time detection with hardware cost competitive to dedicated circuitry. It is the first software programmable architecture which supports the 480 Mbps throughput and 4 us latency of 802.11 n, with hardware cost competitive to dedicated circuit designs. I Through the exploration of hardware and software optimisation strategies of the processor, the computing capacity of FPGA can be efficiently exploited, and the resulting massively parallel softcore processor architecture for MIMO not only achieves the real-time throughput requirements of cutting edge wireless standards, but also enables 42% less equivalent hardware resources and 149\% increase in equivalent hardware efficiency compared to dedicated circuit design without redesigning the Hardware Description Language (HDL)/Register Transfer Level (RTL) hardware. This technique offers the potential to reduce the architecture design problem for DSP systems in general, and dynamic DSP design problems in particular, from a custom circuit design problem to a more tractable processor array configuration and programming problem, with no reduction in implementation efficiency or performance. In addition to high performance embedded architectures, two novel preprocessing algorithms for MIMO detection have been presented. State-of-the-art MIMO detector algorithms, such as FSD, rely on O(M_t"4) complexity of channel sequence preprocessing by Vertical-Bell Laboratories Layered Space-Time (V-BLAST). This high complexity preprocessing stage has not been recorded as real-time. By combining Sorted OR Decomposition (SORD) and Post Sorting Optimisation Algorithm (PSOA) with a particular FSD ordering scheme, this thesis describes a computationally efficient preprocessing solution for FSD. When compared to conventional MIMO preprocessing algorithms, SORD reduces the computational complexity of 4x4 to 7x7 MIMO cases by over 60-70%, suffering merely 0.16-0.26 dB performance reduction at the Bit Error Rate (BER) of 10"{-4}; in the cases where SORD fails to find optimal order, e.g., 8x8 to 16x16 MIMO cases, PSOA is applied after SORD to reduces the complexity by 28-55%, maintaining quasi Maximum Likelihood (quasi-ML) performance. The first real-time preprocessor architecture implemented by massively parallel softcore on FPGA also presents this saving.