2,149 research outputs found

    Generalized Balanced Tournament Packings and Optimal Equitable Symbol Weight Codes for Power Line Communications

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    Generalized balance tournament packings (GBTPs) extend the concept of generalized balanced tournament designs introduced by Lamken and Vanstone (1989). In this paper, we establish the connection between GBTPs and a class of codes called equitable symbol weight codes. The latter were recently demonstrated to optimize the performance against narrowband noise in a general coded modulation scheme for power line communications. By constructing classes of GBTPs, we establish infinite families of optimal equitable symbol weight codes with code lengths greater than alphabet size and whose narrowband noise error-correcting capability to code length ratios do not diminish to zero as the length grows

    Further combinatorial constructions for optimal frequency-hopping sequences

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    AbstractFrequency-hopping multiple-access (FHMA) spread-spectrum communication systems employing multiple frequency shift keying as data modulation technique were investigated by Fuji-Hara, Miao and Mishima [R. Fuji-Hara, Y. Miao, M. Mishima, Optimal frequency hopping sequences: A combinatorial approach, IEEE Trans. Inform. Theory 50 (2004) 2408โ€“2420] from a combinatorial approach, where a correspondence between frequency-hopping (FH) sequences and partition-type cyclic difference packings was established, and several combinatorial constructions were provided for FHMA systems with a single optimal FH sequence. In this paper, by means of this correspondence, we describe more combinatorial constructions for such optimal FH sequences. As a consequence, more new infinite series of optimal FH sequences are obtained

    New Protograph-Based Construction of GLDPC Codes for Binary Erasure Channel and LDPC Codes for Block Fading Channel

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    ํ•™์œ„๋…ผ๋ฌธ(๋ฐ•์‚ฌ) -- ์„œ์šธ๋Œ€ํ•™๊ต๋Œ€ํ•™์› : ๊ณต๊ณผ๋Œ€ํ•™ ์ „๊ธฐยท์ •๋ณด๊ณตํ•™๋ถ€, 2022.2. ๋…ธ์ข…์„  ๊ต์ˆ˜๋‹˜.์ด ํ•™์œ„ ๋…ผ๋ฌธ์—์„œ๋Š” ๋‹ค์Œ ๋‘ ๊ฐ€์ง€์˜ ์—ฐ๊ตฌ๊ฐ€ ์ด๋ฃจ์–ด์กŒ๋‹ค: i) ์ด์ง„ ์†Œ์‹ค ์ฑ„๋„์—์„œ ์ƒˆ๋กœ์šด ๊ตฌ์กฐ์˜ ํ”„๋กœํ† ๊ทธ๋ž˜ํ”„ ๊ธฐ๋ฐ˜ generalized low-density parity-check (GLDPC) ๋ถ€ํ˜ธ์˜ ์„ค๊ณ„ ๋ฐฉ๋ฒ• ii) ๋ธ”๋ก ํŽ˜์ด๋”ฉ ์ฑ„๋„์„ ์œ„ํ•œ ํ”„๋กœํ† ๊ทธ๋ž˜ํ”„ ๊ธฐ๋ฐ˜์˜ LDPC ๋ถ€ํ˜ธ ์„ค๊ณ„. ์ฒซ ๋ฒˆ์งธ๋กœ, ์ด์ง„ ์†Œ์‹ค ์ฑ„๋„์—์„œ ์ƒˆ๋กญ๊ฒŒ ์ œ์•ˆ๋œ ๋ถ€๋ถ„์  ๋„ํ•‘ ๊ธฐ๋ฒ•์„ ์ด์šฉํ•œ ํ”„๋กœํ† ๊ทธ๋ž˜ํ”„ ๊ธฐ๋ฐ˜์˜ GLDPC ๋ถ€ํ˜ธ๊ฐ€ ์ œ์•ˆ๋˜์—ˆ๋‹ค. ๊ธฐ์กด์˜ ํ”„๋กœํ† ๊ทธ๋ž˜ํ”„ ๊ธฐ๋ฐ˜์˜ GLDPC ๋ถ€ํ˜ธ์˜ ๊ฒฝ์šฐ ํ”„๋กœํ† ๊ทธ๋ž˜ํ”„ ์˜์—ญ์—์„œ single parity-check (SPC) ๋…ธ๋“œ๋ฅผ generalized constraint (GC) ๋…ธ๋“œ๋กœ ์น˜ํ™˜(๋„ํ•‘)ํ•˜๋Š” ํ˜•ํƒœ๋กœ ๋ถ€ํ˜ธ๊ฐ€ ์„ค๊ณ„๋˜์–ด ์—ฌ๋Ÿฌ ๋ณ€์ˆ˜ ๋…ธ๋“œ ๊ฑธ์ณ GC ๋…ธ๋“œ๊ฐ€ ์—ฐ๊ฒฐ๋˜๋Š” ํ˜•ํƒœ๋ฅผ ๊ฐ€์ง„๋‹ค. ๋ฐ˜๋ฉด, ์ œ์•ˆ๋œ ๋ถ€๋ถ„์  ๋„ํ•‘ ๊ธฐ๋ฒ•์€ ํ•œ ๊ฐœ์˜ ๋ณ€์ˆ˜ ๋…ธ๋“œ์— GC ๋…ธ๋“œ๋ฅผ ์—ฐ๊ฒฐํ•˜๋„๋ก ๋งŒ๋“ค ์ˆ˜ ์žˆ๋‹ค. ๋ฐ”๊ฟ” ๋งํ•˜๋ฉด, ์ œ์•ˆ๋œ ๋ถ€๋ถ„์  ๋„ํ•‘ ๊ธฐ๋ฒ•์€ ๋” ์„ธ๋ฐ€ํ•œ ๋„ํ•‘์ด ๊ฐ€๋Šฅํ•ด์„œ ๊ฒฐ๊ณผ์ ์œผ๋กœ ๋ถ€ํ˜ธ ์„ค๊ณ„์— ์žˆ์–ด ๋†’์€ ์ž์œ ๋„๋ฅผ ๊ฐ€์ง€๊ณ  ๋” ์„ธ๋ จ๋œ ๋ถ€ํ˜ธ ์ตœ์ ํ™”๊ฐ€ ๊ฐ€๋Šฅํ•˜๋‹ค. ๋ณธ ํ•™์œ„ ๋…ผ๋ฌธ์—์„œ๋Š” ๋ถ€๋ถ„์  ๋„ํ•‘๊ณผ PEXIT ๋ถ„์„์„ ์ด์šฉํ•˜์—ฌ partially doped GLDPC (PD-GLDPC) ๋ถ€ํ˜ธ๋ฅผ ์„ค๊ณ„ํ•˜๊ณ  ์ตœ์ ํ™” ํ•˜์˜€๋‹ค. ๋”๋ถˆ์–ด, PD-GLDPC ๋ถ€ํ˜ธ์˜ ์ผ๋ฐ˜์  ์ตœ์†Œ ๊ฑฐ๋ฆฌ๋ฅผ ๊ฐ€์ง€๋Š” ์กฐ๊ฑด์„ ์ œ์‹œํ•˜์˜€๊ณ  ์ด๋ฅผ ์ด ๋ก ์ ์œผ๋กœ ์ฆ๋ช…ํ•˜์˜€๋‹ค. ๊ฒฐ๊ณผ์ ์œผ๋กœ, ์ œ์•ˆ๋œ PD-GLDPC ๋ถ€ํ˜ธ๋Š” ํ˜„์กดํ•˜๋Š” GLDPC ๋ถ€ํ˜ธ์˜ ์„ฑ๋Šฅ๋ณด๋‹ค ์œ ์˜๋ฏธํ•˜๊ฒŒ ์›Œํ„ฐํ”Œ ์„ฑ๋Šฅ์ด ์ข‹์•˜๊ณ  ๋™์‹œ์— ์˜ค๋ฅ˜ ๋งˆ๋ฃจ๊ฐ€ ์—†์—ˆ๋‹ค. ๋งˆ์ง€๋ง‰์œผ๋กœ, ์ตœ์ ํ™”๋œ PD-GLDPC ๋ถ€ํ˜ธ๋Š” ํ˜„์กดํ•˜๋Š” ์ตœ์‹  ๋ธ”๋ก LDPC ๋ถ€ํ˜ธ๋“ค์— ๊ทผ์ ‘ํ•œ ์„ฑ๋Šฅ์„ ๊ฐ€์ง์„ ๋ณด์—ฌ์ฃผ์—ˆ๋‹ค. ๋‘ ๋ฒˆ์งธ๋กœ, ๋ธ”๋ก ํŽ˜์ด๋”ฉ (BF) ์ฑ„๋„์—์„œ resolvable block design (RBD)๋ฅผ ์ด์šฉํ•œ ํ”„๋กœํ† ๊ทธ๋ž˜ํ”„ LDPC ๋ถ€ํ˜ธ ์„ค๊ณ„๊ฐ€ ์ด๋ฃจ์–ด์กŒ๋‹ค. ์ œ์•ˆ๋œ ๋ถ€ํ˜ธ์˜ ์„ฑ๋Šฅ์„ ํ™•์ธํ•˜๊ธฐ ์œ„ํ•œ ๋น„ํŠธ ์˜ค๋ฅ˜์œจ์˜ ์ƒํ•œ์„ ๊ฐ๋งˆ ์ง„ํ™”๋ผ๋Š” ์ œ์•ˆ๋œ ๊ธฐ๋ฒ•์„ ์ด์šฉํ•ด ์œ ๋„ํ•˜์˜€๋‹ค. ๋˜ํ•œ, ์‹œ๋ฎฌ๋ ˆ์ด์…˜์„ ํ†ตํ•ด ์œ ๋„๋œ ์˜ค๋ฅ˜์œจ ์ƒํ•œ๊ณผ ๋ถ€ํ˜ธ์˜ ํ”„๋ ˆ์ž„ ์˜ค๋ฅ˜์œจ์ด ๋†’์€ SNR ์˜์—ญ์—์„œ ์ฑ„๋„ outage ํ™•๋ฅ ์— ๊ทผ์ ‘ํ•จ์„ ์•Œ ์ˆ˜ ์žˆ๋‹ค.In this dissertation, two main contributions are given as: i) new construction methods for protograph-based generalized low-density parity-check (GLDPC) codes for the binary erasure channel using partial doping technique and ii) new design of protograph-based low-density parity-check (LDPC) codes for the block fading channel using resolvable block design. First, a new code design technique, called partial doping, for protograph-based GLDPC codes is proposed. While the conventional construction method of protograph-based GLDPC codes is to replace some single parity-check (SPC) nodes with generalized constraint (GC) nodes applying to multiple connected variable nodes (VNs) in the protograph, the proposed technique of partial doping can select any number of partial VNs in the protograph to be protected by GC nodes. In other words, the partial doping technique enables finer tuning of doping, which gives higher degrees of freedom in the code design and enables a sophisticated code optimization. The proposed partially doped GLDPC (PD-GLDPC) codes are constructed using the partial doping technique and optimized by the protograph extrinsic information transfer (PEXIT) analysis. In addition, the condition guaranteeing the linear minimum distance growth of the PD-GLDPC codes is proposed and analytically proven so that the PD-GLDPC code ensembles satisfying this condition have the typical minimum distance. Consequently, the proposed PD-GLDPC codes outperform the conventional GLDPC codes with a notable improvement in the waterfall performance and without the error floor phenomenon. Finally, the PD-GLDPC codes are shown to achieve a competitive performance compared to the existing state-of-the-art block LDPC codes. Second, the protograph-based LDPC codes constructed from resolvable balanced incomplete block design (RBIBD) are designed and proposed for block fading (BF) channel. In order to analyze the performance of the proposed LDPC codes, the upper bounds on bit error rate (BER) using the novel method called gamma evolution are derived. In addition, the numerical analysis shows that the upper bound and the frame error rate (FER) of the proposed LDPC codes approach the channel outage probability in a finite signal-to-noise ratio (SNR) region.1 INTRODUCTION 1 1.1 Background 1 1.2 Overview of Dissertation 3 2 Overview of LDPC Codes 5 2.1 LDPC Codes 5 2.2 Decoding of LDPC Codes in the BEC 7 2.3 Analysis tool for LDPC Codes 8 2.3.1 Density Evolution 8 2.4 Protograph-Based LDPC Codes 9 3 Construction of Protograph-Based Partially Doped Generalized LDPC Codes 11 3.1 Code Structure of Protograph-Based GLDPC Ensembles 14 3.1.1 Construction of Protograph Doped GLDPC Codes 14 3.1.2 PEXIT Analysis and Decoding Process of Protograph Doped GLDPC Codes 15 3.2 The Proposed PD-GLDPC Codes 18 3.2.1 Construction Method of PD-GLDPC Codes 18 3.2.2 PEXIT Analysis of PD-GLDPC Codes 22 3.2.3 Condition for the Existence of the Typical Minimum Distance of the PD-GLDPC Code Ensemble 23 3.2.4 Comparison between Proposed PD-GLDPC Codes and Protograph Doped GLDPC Codes 25 3.3 Optimization of PD-GLDPC Codes 26 3.3.1 Construction of PD-GLDPC Codes from Regular Protographs 26 3.3.2 Differential Evolution-Based Code Construction from the Degree Distribution of Random LDPC Code Ensembles 28 3.3.3 Optimization of PD-GLDPC Codes Using Protograph Differential Evolution 32 3.4 Numerical Results and Analysis 36 3.4.1 Simulation Result for Optimized PD-GLDPC Code from Regular and Irregular Random LDPC Code Ensembles 36 3.4.2 Simulation Result for PD-GLDPC Code from Optimized Protograph 43 3.5 Proof of Theorem 1: The Constraint for the Existence of the Typical Minimum Distance of the Proposed Protograph-Based PD-GLDPC Codes 45 4 Design of Protograph-Based LDPC Code Using Resolvable Block Design for Block Fading Channel 52 4.1 Problem Formulation 53 4.1.1 BF Channel Model 53 4.1.2 Performance Metrics of BF Channel 54 4.1.3 Protograph-Based LDPC Codes and QC LDPC Codes 57 4.2 New Construction of Protograph-Based LDPC Codes from Resolvable Block Designs 57 4.2.1 Resolvable Block Designs 57 4.2.2 Construction of the Proposed Protograph-Based LDPC Codes 59 4.2.3 Theoretical Analysis of the Proposed Protograph-Based LDPC Code from RBD 61 4.2.4 Numerical Analysis of the Proposed Protograph-Based LDPC Code Codes for BF Channel 65 4.2.5 BER Comparison with Analytical Results from Gamma Evolution 65 4.2.6 FER Comparison with Channel Outage Probability 67 5 Conclusions 69 Abstract (In Korean) 78๋ฐ•

    Proceedings of Mathsport international 2017 conference

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    Proceedings of MathSport International 2017 Conference, held in the Botanical Garden of the University of Padua, June 26-28, 2017. MathSport International organizes biennial conferences dedicated to all topics where mathematics and sport meet. Topics include: performance measures, optimization of sports performance, statistics and probability models, mathematical and physical models in sports, competitive strategies, statistics and probability match outcome models, optimal tournament design and scheduling, decision support systems, analysis of rules and adjudication, econometrics in sport, analysis of sporting technologies, financial valuation in sport, e-sports (gaming), betting and sports
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