检索结果-内蒙古大学图书馆

On Fast-Decodable Space-Time Block Codes

IEEE TRANSACTIONS ON INFORMATION THEORY 2009年第2期55卷 524-530页

作者： Biglieri, Ezio Hong, Yi Viterbo, Emanuele UPF DTIC Barcelona Spain Univ Coll Swansea Inst Adv Telecom Swansea SA2 8PP W Glam Wales Univ Calabria DEIS I-87036 Arcavacata Di Rende CS Italy

We focus on full-rate, fast-decodable space-time block codes (STBCs) for 2 x 2 and 4 x 2 multiple-input multiple-output (MIMO) transmission. We first derive conditions and design criteria for reduced-complexity maximum-likelihood (ML) decodable 2 x 2 STBCs, and we apply them to two families of codes that were recently discovered. Next, we derive a novel reduced-complexity 4 x 2 STBC, and show that it outperforms all previously known codes with certain constellations.

关键词： Alamouti code decoding complexity multiple-input multiple-output (MIMO) quasi-orthogonal space-time block codes (STBCs) sphere decoder

来源：评论

学校读者我要写书评

暂无评论

Bandwidth efficient concatenated coding schemes

引用

IET COMMUNICATIONS 2010年第1期4卷 26-31页

作者： Ma, S. -C. Natl Taipei Univ Technol Dept Elect Engn Taipei 106 Taiwan

Concatenated coded modulation is a powerful method for constructing coding schemes with large coding gain and low decoding complexity. For the concatenated scheme, the outer code has redundancy and the overall transmission rate is reduced. The problem of bandwidth expansion can be overcome by two procedures. First, the code rate of inner codes is increased with a special coding design. Second, a two-level concatenated scheme is constructed to compensate the rate loss. This way, the low-complexity concatenated coded modulation schemes can be designed without bandwidth expansion as compared with the uncoded scheme.

关键词： low-complexity concatenated coded modulation scheme concatenated codes modulation coding computational complexity decoding complexity two-level concatenated scheme bandwidth efficient concatenated coding schemes decoding Codes

来源：评论

学校读者我要写书评

暂无评论

A personal history of the Viterbi algorithm

引用

IEEE SIGNAL PROCESSING MAGAZINE 2006年第4期23卷 120-+页

作者： Viterbi, Andrew J. Universidad Carlos III de Madrid MADRID Spain

This paper describes how Andrew J. Viterbi developed a non-sequential decoding algorithm which proved useful in showing the superiority of convolutional codes over block codes for a given degree of decoding complexity. The Viterbi algorithm is now used in most digital cellular phones and digital satellite receivers as well as in such diverse fields as magnetic recoding, voice recognition, and DNA sequence analysis.

关键词： Viterbi decoding block codes computational complexity convolutional codes history Viterbi algorithm decoding complexity nonsequential decoding algorithm Social history convolutional coding complexity classes Viterbi algorithm digital cellular phone Block codes digital satellite receiver Viterbi decoding

来源：评论

学校读者我要写书评

暂无评论

Improved low complexity hybrid turbo codes and union bound analysis

引用

IET COMMUNICATIONS 2011年第4期5卷 512-518页

作者： Bhise, A. Vyavahare, P. D. KJS Inst Engn & Informat Technol Dept Elect & Telecommun Engn Mumbai Maharashtra India SGS Inst Technol & Sci Dept Elect & Telecommun Engn Indore Madhya Pradesh India

Turbo convolutional codes (TCC) are excellent error correcting codes for wireless channels. However, TCC decoders require large decoding complexity. Moreover, complexity of TCC decoder does not reduce even if puncturing is used to change the coding rate. Modified turbo codes require lower decoding complexity than TCC as they use multiple concatenations of simple block codes and convolutional codes. Recently, a class of modified turbo codes called low complexity hybrid turbo codes (LCHTC) and improved low complexity hybrid turbo codes (ILCHTC) have been proposed. It has been shown that LCHTC and ILCHTC achieve bit error rate (BER) which is comparable to TCC and have much lower decoding complexity. Simulation results show that BER performance of ILCHTC is better than that of LCHTC. Rate-1/3 ILCHTC achieve BER of 10(-5) at bit energy-to-noise ratio (E-b/N-0) of 1.9 dB, which is 0.4 dB higher than E-b/N-0 for TCC adopted by third generation partnership project (3GPP). Moreover, ILCHTC and LCHTC decoders require half the number of computations as compared to those required for TCC decoder. In this study, union-bound analysis of ILCHTC is presented to investigate BER performance <10(-6). For large interleaver lengths, analysis of theoretical union bound requires numerous computations. Therefore approximate analysis of union bound is derived from theoretical union bound. It is shown that the analysis of approximate union bound achieves reasonable accuracy. Moreover, approximate union bound can be evaluated with significantly less computational complexity than the theoretical union bound.

关键词： union bound analysis turbo convolutional codes wireless channel convolutional codes bit error rate error statistics Codes decoding complexity BER performance wireless channels decoding coding rate error correction codes third generation partnership project low complexity hybrid turbo codes turbo codes modified turbo codes computational complexity decoder error correcting codes Radio links and equipment Information theory Other topics in statistics

来源：评论

学校读者我要写书评

暂无评论

Generalized minimum-distance decoding of Euclidean-space codes and lattices

引用

IEEE TRANSACTIONS ON INFORMATION THEORY 1996年第6期42卷 1992-2026页

作者： Forney, GD Vardy, A UNIV ILLINOIS COORDINATED SCI LAB URBANA IL 61801 USA

It is shown that multistage generalized minimum-distance (GMD) decoding of Euclidean-space codes and lattices can provide an excellent tradeoff between performance and complexity, We introduce a reliability metric for Gaussian channels that is easily computed from an inner product, and prove that a multistage GMD decoder using this metric is a bounded-distance decoder up to the true packing radius, The effective error coefficient of multistage GMD decoding is determined, Two simple modifications in the GMD decoding algorithm that drastically reduce this error coefficient are proposed, It is shown that with these modifications GMD decoding achieves the error coefficient of maximum-likelihood decoding for block codes and for generalized Construction A lattices. Multistage GMD decoding of the lattices D-4, E(8), K-12, BW16, and Lambda(24) is investigated in detail, For K-12, BW16, and Lambda(24), the GMD decoders have considerably lower complexity than the best known maximum-likelihood or bounded-distance decoding algorithms, and appear to be the most practically attractive decoders available, For high-dimensional codes and lattices (greater than or equal to 64 dimensions) maximum-likelihood decoding becomes infeasible, while GMD decoding algorithms remain quite practical, As an example, we devise a multistage GMD decoder for a 128-dimensional sphere packing with a nominal coding gain of 8.98 dB that attains an effective error coefficient of 1 365 760. This decoder requires only about 400 real operations, in addition to algebraic errors-and-erasures decoding of certain BCH and Hamming codes, It therefore appears to be practically feasible to implement algebraic multistage GMD decoders for high-dimensional sphere packings, and thus achieve high effective coding gains.

关键词： multilevel codes multistage decoding generalized minimum-distance decoding effective error coefficient sphere packings and lattices decoding complexity

来源：评论

学校读者我要写书评

暂无评论

The trellis complexity of convolutional codes

引用

IEEE TRANSACTIONS ON INFORMATION THEORY 1996年第6期42卷 1855-1864页

作者： McEliece, RJ Lin, W Department of Electrical Engineering California Institute of Technology Pasadena CA USA

It has long been known that convolutional codes have a natural, regular, trellis structure that facilitates the implementation of Viterbi's algorithm [35], [11]. It has gradually become apparent that linear block codes also have a natural, though not in general a regular, ''minimal'' trellis structure, which allows them to be decoded with a Viterbi-like algorithm [2], [36], [25], [12], [30], [16], [13], [18], [27], [28], [9], [17]. In both cases, the complexity of an unenhanced Viterbi decoding algorithm can be accurately estimated by the number of trellis edge symbols per encoded bit. It would therefore appear that we are in a good position to make a fair comparison of the Viterbi decoding complexity of block and convolutional codes. Unfortunately, however, this comparison is somewhat muddled by the fact that some convolutional codes, the punctured convolutional codes [5], are known to have trellis representations which are significantly less complex than the conventional trellis. In other words, the conventional trellis representation for a convolutional code may not be the ''minimal'' trellis representation. Thus ironically, we seem to know more about the minimal trellis representation for block than for convolutional codes. In this paper we provide a remedy, by developing a theory of minimal trellises for convolutional codes. (A similar theory has recently been given by Sidorenko and Zyablov [32].) This allows us to make a direct performance-complexity comparison for block and convolutional codes. A by-product of our work is an algorithm for choosing, from among all generator matrices for a given convolutional code, what we call a trellis-canonical generator matrix, from which the minimal trellis for the code can de directly constructed. Another by-product is that in the new theory, punctured convolutional codes no longer appear as a special class, but simply as high-rate convolutional codes whose trellis complexity is unexpectedly small.

关键词： convolutional code minimal trellis decoding complexity

来源：评论

学校读者我要写书评

暂无评论

Design of trellis decoders for block-coded modulation schemes

引用

IEE PROCEEDINGS-COMMUNICATIONS 2000年第1期147卷 1-7页

作者： Petronio, MA Carrasco, RA Staffordshire Univ Sch Engn & Adv Technol Stafford ST18 0AD Staffs England

Block-coded modulation (BCM) combines bandwidth-efficient modulation techniques with error-correction capabilities to allow efficient data transmission over mobile communication channels. The main shortcoming of BCM is the complex decoding process for which, until today, mainly suboptimum decoding methods are used, because existing approaches for trellis decoders are limited to a small subset of possible BCM schemes. The authors address this shortcoming by introducing a new technique for the construction of trellis decoders for arbitrary BCM schemes. This technique is based on a new approach for the calculation of the trellis state vector and a computationally efficient recursive method for the construction of the trellis. A large number of simulation results for BCM schemes with various QAM constellations are presented, and comparisons in terms of performance and decoding complexity allow the formulation of guidelines for the choice of efficient coding schemes.

关键词： block-coded modulation schemes channel coding trellis state vector modulation coding bandwidth-efficient modulation data communication QAM constellations Mobile radio systems error-correction capabilities mobile communication channels trellis codes block codes decoding complexity error correction codes efficient data transmission decoding BCM quadrature amplitude modulation mobile radio trellis decoders simulation results recursive method Codes

来源：评论

学校读者我要写书评

暂无评论

Distributed Cyclotomic QOSTBC with Low End-to-End Delay for Full-Duplex Multi-relay Systems

引用

WIRELESS PERSONAL COMMUNICATIONS 2015年第4期82卷 2611-2621页

作者： Jiang, Hua Cheng, Hao Shen, Lizhen Liu, Guoqing Nanjing Tech Univ Coll Sci Nanjing Jiangsu Peoples R China Nanjing Tech Univ Coll Biotechnol & Pharmaceut Engn Nanjing Jiangsu Peoples R China

In this paper, we propose a novel distributed space-time block coding (STBC) scheme for multi-relay system. We consider the full-duplex cooperation which is more spectrally efficient than the half-duplex cooperation. In full-duplex mode, the newscheme requires relay nodes to stack only every two successive symbols for swapping. Thus, the end-to-end delaymay be lower than that induced by orthogonal STBC and conventional quasi-orthogonal STBC (QOSTBC) schemes. We show the new distributed STBC is capable of achieving cooperative diversity by using multi-dimensional rotated signal constellation. Besides, due to the simpler maximum-likelihood metric compared to that of conventional QOSTBC, the code achieves a lower decoding complexity without any performance degradation. To furthermore reduce complexity, the fast sphere decoder is adopted for the proposed code. The proposed transmission scheme is evaluated and compared in terms of performance by simulation.

关键词： Space-time block coding (STBC) Cooperative system Full-duplex End-to-end delay decoding complexity

来源：评论

学校读者我要写书评

暂无评论

A Low-complexity Coded Transmission Scheme Over Finite-Buffer Relay Links

引用

IEEE TRANSACTIONS ON COMMUNICATIONS 2018年第7期66卷 2873-2887页

作者： Li, Ye Zhang, Shibing Wang, Jue Ji, Xiaodong Wu, Huangnan Bao, Zhihua Nantong Univ Sch Elect & Informat Nantong 226019 Peoples R China Nantong Res Inst Adv Commun Technol Nantong 226019 Peoples R China

Relay transmissions play an important role in many types of communication systems. In this paper, we consider packet-level coded transmissions over lossy relay links with the finite-buffer and coding coefficients delivery cost constraints. We propose a low-complexity coding scheme where packets are encoded from sequentially formed random subsets of source packets called batches. The relay recodes only from the buffered packets belonging to the same batch to maintain the code sparsity, lowering the packet header overhead and the decoding complexity compared to the random linear network coding (RLNC). To analyze the performance, we first propose an absorbing Markov chain model to analyze the RLNC transmission over finite-buffer relay links. The finite-length analysis not only provides a lower bound on the completion time using any sparser random codes but also characterizes each individual batch's transmission of the proposed code. Based on the analysis, another Markov chain is proposed to determine the decoding failure probability and the expected completion time of the batch coding scheme. As shown through analysis and simulations, the proposed scheme achieves higher effective end-to-end rates than RLNC when the coding coefficients delivery cost is considered and is also with much lowered decoding complexity thanks to its sparseness.

关键词： Relay finite-buffer sparse network codes decoding complexity absorbing Markov chain

来源：评论

学校读者我要写书评

暂无评论

Multigroup ML Decodable Collocated and Distributed Space-Time Block Codes

引用

IEEE TRANSACTIONS ON INFORMATION THEORY 2010年第7期56卷 3221-3247页

作者： Rajan, G. Susinder Rajan, B. Sundar Atheros India LLC Madras 600004 Tamil Nadu India Indian Inst Sci Dept Elect Commun Engn Bangalore 560012 Karnataka India

In this paper, collocated and distributed space-time block codes (DSTBCs) which admit multigroup maximum-likelihood (ML) decoding are studied. First, the collocated case is considered and the problem of constructing space-time block codes (STBCs) which optimally tradeoff rate and ML decoding complexity is posed. Recently, sufficient conditions for multigroup ML decodability have been provided in the literature and codes meeting these sufficient conditions were called Clifford unitary weight (CUW) STBCs. An algebraic framework based on extended Clifford algebras (ECAs) is proposed to study CUW STBCs and using this framework, the optimal tradeoff between rate and ML decoding complexity of CUW STBCs is obtained for few specific cases. Code constructions meeting this tradeoff optimally are also provided. The paper then focuses on multigroup ML decodable DSTBCs for application in synchronous wireless relay networks and three constructions of four-group ML decodable DSTBCs are provided. Finally, the orthogonal frequency-division multiplexing (OFDM)-based Alamouti space-time coded scheme proposed by Li-Xia for a 2-relay asynchronous relay network is extended to a more general transmission scheme that can achieve full asynchronous cooperative diversity for arbitrary number of relays. It is then shown how differential encoding at the source can be combined with the proposed transmission scheme to arrive at a new transmission scheme that can achieve full cooperative diversity in asynchronous wireless relay networks with no channel information and also no timing error knowledge at the destination node. Four-group decodable DSTBCs applicable in the proposed OFDM-based transmission scheme are also given.

关键词： Asynchronous cooperative communication Clifford algebra cooperative diversity decoding complexity distributed space-time codes orthogonal frequency-division multiplexing (OFDM) space-time codes

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：