检索结果-内蒙古大学图书馆

Nonlinear bcjr equalizer for suppression of intrachannel nonlinearities in 40 Gb/s optical communications systems

OPTICS EXPRESS 2006年第11期14卷 4625-4635页

作者： Djordjevic, Ivan B. Vasic, Bane Univ Arizona Dept Elect & Comp Engn Tucson AZ 85721 USA

A maximum a posteriori probability ( MAP) symbol decoding supplemented with iterative decoding is proposed as an effective mean for suppression of intrachannel nonlinearities. The MAP detector, based on Bahl-Cocke-Jelinek-Raviv algorithm, operates on the channel trellis, a dynamical model of intersymbol interference, and provides soft-decision outputs processed further in an iterative decoder. A dramatic performance improvement is demonstrated. The main reason is that the conventional maximum-likelihood sequence detector based on Viterbi algorithm provides hard-decision outputs only, hence preventing the soft iterative decoding. The proposed scheme operates very well in the presence of strong intrachannel intersymbol interference, when other advanced forward error correction schemes fail, and it is also suitable for 40 Gb/s upgrade over existing 10 Gb/s infrastructure. (c) 2006 Optical Society of America.

关键词： .forward decoding correction constrained suppression nonlinearities OPTICAL COMMUNICATIONS decoder Intersymbol interference performance improvement trellis LDPC Intrachannel bcjr algorithm Nonlinear bcjr

来源：评论

学校读者我要写书评

暂无评论

20 Years of Turbo Coding and Energy-Aware Design Guidelines for Energy-Constrained Wireless Applications

引用

IEEE COMMUNICATIONS SURVEYS AND TUTORIALS 2016年第1期18卷 8-28页

作者： Brejza, Matthew F. Li, Liang Maunder, Robert G. Al-Hashimi, Bashir M. Berrou, Claude Hanzo, Lajos Univ Southampton Sch Elect & Comp Sci Southampton SO17 1BJ Hants England Cirrus Log Inc Newbury RG14 2PZ Berks England Technople Brest Iroise CS 83818 F-29238 Brest France

During the last two decades, wireless communication has been revolutionized by near-capacity error-correcting codes (ECCs), such as turbo codes (TCs), which offer a lower bit error ratio (BER) than their predecessors, without requiring an increased transmission energy consumption (EC). Hence, TCs have found widespread employment in spectrum-constrained wireless communication applications, such as cellular telephony, wireless local area network, and broadcast systems. Recently, however, TCs have also been considered for energy-constrained wireless communication applications, such as wireless sensor networks and the 'Internet of Things.' In these applications, TCs may also be employed for reducing the required transmission EC, instead of improving the BER. However, TCs have relatively high computational complexities, and hence, the associated signal-processing-related ECs are not insignificant. Therefore, when parameterizing TCs for employment in energy-constrained applications, both the processing EC and the transmission EC must be jointly considered. In this tutorial, we investigate holistic design methodologies conceived for this purpose. We commence by introducing turbo coding in detail, highlighting the various parameters of TCs and characterizing their impact on the encoded bit rate, on the radio frequency bandwidth requirement, on the transmission EC and on the BER. Following this, energy-efficient TC decoder application-specific integrated circuit (ASIC) architecture designs are exemplified, and the processing EC is characterized as a function of the TC parameters. Finally, the TC parameters are selected in order to minimize the sum of the processing EC and the transmission EC.

关键词： Turbo code bcjr algorithm energy efficiency holistic design optimization wireless sensor network

来源：评论

学校读者我要写书评

暂无评论

A minimax robust decoding algorithm

引用

IEEE TRANSACTIONS ON INFORMATION THEORY 2000年第3期46卷 1158-1167页

作者： Wei, L Li, Z James, MR Petersen, IR Australian Natl Univ Fac Engn & Informat Technol Dept Engn Canberra ACT 0200 Australia Australian Def Force Acad Dept Elect Engn Canberra ACT 2601 Australia

In this correspondence we study the decoding problem in an uncertain noise environment. If the receiver knows the noise probability density function (pdf) at each time slot or its a priori probability the standard Viterbi algorithm (VA) or the a posteriori probability (APP) algorithm can achieve optimal performance. However, if the actual noise distribution differs From the noise model used to design the receiver, there can be significant performance degradation due to the model mismatch. The minimax concept is used to minimize the worst possible error performance over a family of possible channel noise pdf's. We show that the optimal robust scheme is difficult to derive;therefore, alternative, practically feasible, robust decoding schemes are presented and implemented on VA decoder and two-way APP decoder. Performance analysis and numerical results show our robust decoders have a performance advantage over standard decoders in uncertain noise channels, with no or little computational overhead. Our robust decoding approach can also explain why for turbo decoding overestimating the noise variance gives better results than underestimating it.

关键词： bcjr algorithm impulsive noise minimax min-sum algorithm robust signal processing sum-product algorithm turbo decoding two-way APP algorithm uncertain channel Viterbi algorithm

来源：评论

学校读者我要写书评

暂无评论

Binary-Input Non-Line-of-Sight Solar-Blind UV Channels: Modeling, Capacity and Coding

引用

JOURNAL OF OPTICAL COMMUNICATIONS AND NETWORKING 2012年第12期4卷 1008-1017页

作者： El-Shimy, Mohamed A. Hranilovic, Steve McMaster Univ Dept Elect & Comp Engn Hamilton ON L8S 4K1 Canada

There has been recent interest in establishing non-line-of-sight links in the solar-blind ultraviolet region for outdoor optical wireless communications. This paper presents a novel channel model combining both photon propagation and detection statistics. The channel capacity with binary inputs is numerically computed for on-off keying and 4-pulse-position modulation (4-PPM) at different baud rates. To approach the capacity, error control coding is applied and a message passing decoding technique is outlined. Simulation results for a running example through the paper indicate that, at a given power, there is an optimum transmitted baud rate that maximizes the achievable data rate on such links. With the application of proper coding techniques, it is demonstrated that a near fifty-fold increase in rate over previous reported designs for this channel is feasible.

关键词： Atmospheric scattering bcjr algorithm Inter-symbol interference channel LDPC codes Photon statistics

来源：评论

学校读者我要写书评

暂无评论

Joint detection/decoding algorithms for non-binary low-density parity-check codes over inter-symbol interference channels

引用

IET COMMUNICATIONS 2013年第14期7卷 1522-1531页

作者： Zhao, Shancheng Lu, Zhifei Ma, Xiao Bai, Baoming Sun Yat Sen Univ Dept Elect & Commun Engn Guangzhou 510275 Guangdong Peoples R China ISN Xidian Univ State Key Lab Xian 710071 Peoples R China

This study is concerned with the application of non-binary low-density parity-check (NB-LDPC) codes to binary input inter-symbol interference channels. Two low-complexity joint detection/decoding algorithms are proposed. One is referred to as max-log-MAP/X-EMS algorithm, which is implemented by exchanging soft messages between the max-log-MAP detector and the extended min-sum (EMS) decoder. The max-log-MAP/X-EMS algorithm is applicable to general NB-LDPC codes. The other one, referred to as Viterbi/GMLGD algorithm, is designed in particular for majority-logic decodable NB-LDPC codes. The Viterbi/GMLGD algorithm works in an iterative manner by exchanging hard-decisions between the Viterbi detector and the generalised majority-logic decoder (GMLGD). As a by-product, a variant of the original EMS algorithm is proposed, which is referred to as mu-EMS algorithm. In the mu-EMS algorithm, the messages are truncated according to an adaptive threshold, resulting in a more efficient algorithm. Simulations results show that the max-log-MAP/X-EMS algorithm performs as well as the traditional iterative detection/decoding algorithm based on the bcjr algorithm and theQ-ary sum-product algorithm, but with lower complexity. The complexity can be further reduced for majority-logic decodable NB-LDPC codes by executing the Viterbi/GMLGD algorithm with a performance degradation within one dB. These algorithms provide good candidates for trade-offs between performance and complexity.

关键词： intersymbol interference iterative decoding parity check codes Viterbi decoding joint detection-decoding algorithm nonbinary low-density parity-check code intersymbol interference channel NB-LDPC code binary input intersymbol interference channel max-log-MAP X-EMS algorithm soft message max-log-MAP detector extended min-sum decoder EMS decoder Viterbi GMLGD algorithm majority-logic decoding Viterbi detector generalised majority-logic decoder i1 4-EMS algorithm adaptive threshold iterative detection algorithm iterative decoding algorithm bcjr algorithm Q-ary sumaEuro"product algorithm performance degradation

来源：评论

学校读者我要写书评

暂无评论

Exploring general memory structures in turbo decoders using sliding-window MAP algorithm

引用

IEICE TRANSACTIONS ON COMMUNICATIONS 2003年第11期E86B卷 3163-3173页

作者： Wu, CM Shieh, MD Wu, CH Natl Cheng Kung Univ Dept Elect Engn Tainan 70101 Taiwan

Turbo coding is a powerful coding technique that can provide highly reliable data transmission at extremely low signal-to-noise ratios. Owing to the computational complexity of the employed decoding algorithm, the realization of turbo decoders usually takes a large amount of memory space and potentially long decoding delay. Therefore, an efficient memory management strategy becomes one of the key factors toward successfully implementing turbo decoders. This paper focuses on the development of general structures for efficient memory management of turbo decoders employing the sliding-window (Log-)MAP algorithm. Three different structures and the associated mathematic representations are derived to evaluate the required memory size, average decoding rate, and latency based on the speed and the number of the adopted processors. Comparative results show the dependency of the resulting performance based on a set of parameters;thus provide useful and general information on practical implementations of turbo decoders.

关键词： turbo code bcjr algorithm MAP algorithm sliding window algorithm memory management

来源：评论

学校读者我要写书评

暂无评论

Channel Model and Decoder With Memory for DNA Data Storage With Nanopore Sequencing

引用

IEEE ACCESS 2023年 11卷 52075-52087页

作者： Hamoum, Belaid Dupraz, Elsa Univ Bretagne Sud Lab STICC CNRS UMR 6285 F-56321 Lorient France IMT Atlantique Lab STICC UMR CNRS 6285 F-29238 Brest France

This paper investigates channel coding for DNA data storage, a recent and emerging paradigm in which both substitution errors and synchronization errors (insertions, deletions) are introduced in the stored data. The paper first proposes a novel and accurate statistical channel model to represent errors introduced by the DNA data storage support. The channel model takes the form of a k-order Markov Model which allows to capture both memory in the sequence of channel errors, and statistical dependency between errors and input sequence. The model probabilities are inferred on two sets of data: one set of experimental data, and one set of genomic data. In both cases, we observe a superior accuracy, evaluated from the Kulback-Leibler divergence, of our channel model compared to existing ones. Second, the paper investigates the design of error-correction solutions dedicated to the proposed channel model. It considers a concatenated code construction built from a convolutional decoder which aims to correct synchronization errors, and from an outer LDPC code which corrects residual substitution errors. While this construction was already investigated for i.i.d. errors, this paper shows how to include all the knowledge of the proposed channel model into the convolutional decoder. Numerical results show that the proposed decoding algorithm significantly improves the decoding performance in terms of BER and FER, at the price of an increased decoding complexity.

关键词： DNA Channel models Decoding Memory Sequential analysis Symbols Data models DNA storage channel model coding for DNA data storage concatenated codes convolutional decoders bcjr algorithm

来源：评论

学校读者我要写书评

暂无评论

Joint Decoding of LDPC Codes and Finite-State Channels Via Linear-Programming

引用

IEEE JOURNAL OF SELECTED TOPICS IN SIGNAL PROCESSING 2011年第8期5卷 1563-1576页

作者： Kim, Byung-Hak Pfister, Henry D. Texas A&M Univ Dept Elect & Comp Engn College Stn TX 77843 USA

This paper considers the joint-decoding problem for finite-state channels (FSCs) and low-density parity-check (LDPC) codes. In the first part, the linear-programming (LP) decoder for binary linear codes is extended to perform joint-decoding of binary-input FSCs. In particular, we provide a rigorous definition of LP joint-decoding pseudo-codewords (JD-PCWs) that enables evaluation of the pairwise error probability between codewords and JD-PCWs in AWGN. This leads naturally to a provable upper bound on decoder failure probability. If the channel is a finite-state intersymbol interference channel, then the joint LP decoder also has the maximum-likelihood (ML) certificate property and all integer-valued solutions are codewords. In this case, the performance loss relative to ML decoding can be explained completely by fractional-valued JD-PCWs. After deriving these results, we discovered some elements were equivalent to earlier work by Flanagan on linear-programming receivers. In the second part, we develop an efficient iterative solver for the joint LP decoder discussed in the first part. In particular, we extend the approach of iterative approximate LP decoding, proposed by Vontobel and Koetter and analyzed by Burshtein, to this problem. By taking advantage of the dual-domain structure of the joint-decoding LP, we obtain a convergent iterative algorithm for joint LP decoding whose structure is similar to bcjr-based turbo equalization (TE). The result is a joint iterative decoder whose per-iteration complexity is similar to that of TE but whose performance is similar to that of joint LP decoding. The main advantage of this decoder is that it appears to provide the predictability and superior performance of joint LP decoding with the computational complexity of TE. One expected application is coding for magnetic storage where the required block-error rate is extremely low and system performance is difficult to verify by simulation.

关键词： bcjr algorithm finite-state channels joint-decoding low-density parity-check (LDPC) codes linear-programming (LP) decoding turbo equalization

来源：评论

学校读者我要写书评

暂无评论

Markov Chain Monte Carlo Based Detection for Two-Dimensional Intersymbol Interference Channels

引用

IEEE TRANSACTIONS ON MAGNETICS 2011年第2期47卷 471-478页

作者： Shaghaghi, Mahdi Cai, Kui Guan, Yong Liang Qin, Zhiliang Data Storage Inst DSI Singapore 117608 Singapore Univ Alberta Dept Elect & Comp Engn Edmonton AB T6G 2V4 Canada Nanyang Technol Univ Sch Elect & Elect Engn Singapore 639798 Singapore

Recent advances in ultra-high-density data storage technologies have led to two-dimensional (2-D) intersymbol interference (ISI) in the system. The optimum detection method for 2-D ISI channels has prohibitive computational complexity which makes it impractical. In this paper, we propose a Markov chain Monte Carlo (MCMC) based 2-D detection algorithm whose complexity grows polynomially with the ISI size. When turbo decoded in conjunction with a low-density parity check (LDPC) channel code, the performance of the proposed detection method is evaluated for ultra-high-density bit-patterned magnetic recording (BPMR) systems. Its computational complexity is also analyzed. Our study shows that the proposed detection method significantly reduces the computational burden, while achieving performance better than the bcjr based detection method.

关键词： bcjr algorithm low-density parity-check codes Markov chain Monte Carlo methods turbo decoding two-dimensional intersymbol interference

来源：评论

学校读者我要写书评

暂无评论

Turbo decoding of simple product codes in a two user binary adder channel employing the Bahl-Cocke-Jelinek-Raviv algorithm

引用

TELECOMMUNICATION SYSTEMS 2018年第3期68卷 513-521页

作者： de Souza, I. M. M. Alcoforado, M. L. M. G. da Rocha, V. C., Jr. Univ Pernambuco UPE Telecommun Lab LABTEL Commun Grp GCOM BR-50750470 Recife PE Brazil Univ Fed Pernambuco Dept Elect & Syst Commun Res Grp CODEC BR-50740550 Recife PE Brazil

The main goal in this paper is an investigation of the Bahl-Cocke-Jelinek-Raviv (bcjr) algorithm applied in a turbo decoding scheme. Binary product codes are employed in a turbo coding scheme and the channel model considered is the two user binary adder channel (2-BAC) with additive white Gaussian noise. A trellis for two users is constructed for a pair of product codes tailored for use in the 2-BAC in order to employ the bcjr decoding algorithm. Computer simulation is employed to show that product codes on the 2-BAC, employing low-complexity component codes, produces considerable gain with few iterations under iterative bcjr decoding.

关键词： bcjr algorithm Multiple access channel Iterative decoder Product 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：