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16th International Conference on Combinatorics

作者： Laksman, Efraim Lennerstad, Hakan Nilsson, Magnus Sch Engn Blekinge Inst Technol S-37179 Karlskrona Sweden Sch Comp Blekinge Inst Technol S-37179 Karlskrona Sweden

The minimum Euclidean distance is a fundamental quantity for block coded phase shift keying (PSK). In this paper we improve the bounds for this quantity that are explicit functions of the alphabet size q, block length n and code size |C|. For q = 8, we improve previous results by introducing a general inner distance measure allowing different shapes of a neighborhood for a codeword. By optimizing the parameters of this inner distance measure, we find sharper bounds for the outer distance measure, which is Euclidean. The proof is built upon the Elias critical sphere argument, which localizes the optimization problem to one neighborhood. We remark that any code with q = 8 that fulfills the bound with equality is best possible in terms of the minimum Euclidean distance, for given parameters n and |C|. This is true for many multilevel codes. (C) 2010 Elsevier B.V. All rights reserved.

关键词： block code Phase shift keying Metric Elias' bound Minimal Euclidean distance

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Low-Comprexity Sliding Window block decoding Using Bit-Flipping for OVFDM Systems

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IEEE ACCESS 2017年 5卷 25171-25180页

作者： Zhang, Hongtao Chen, Ying Li, Daoben Wang, Yafeng Beijing Univ Posts & Telecommun Sch Informat & Commun Engn Beijing 100876 Peoples R China

Overlapped frequency division multiplexing (OVFDM) systems can obtain high spectral effciency (SE), which is proportional to the constraint length. However, high decoding complexity imposes the main challenge on OVFDM systems. This paper proposes a low-complexity sliding window ( SW) block decoding algorithm for OVFDM systems, where data symbols are estimated based on the reception of a SW instead of a date frame. Specifically, block code of each SW is decoded by bit-flipping algorithm where the bits to be flipped are selected according to the largest absolute value criterion. Using this criterion, the complexity to obtain the near optimal bit-flipping vector grows only linearly with the SW length. In addition, the study of the decoding algorithm is based on the design of OVFDM encoding structure, where symbols can occupy orthogonal in-phase and quadrature channels simultaneously to further improve SE by a factor of two. Simulation results show that OVFDM SW decoding with bit-flipping algorithm can be used when constraint length is relatively high (constraint length >= 20) because the complexity goes roughly linearly with the increase of constraint length.

关键词： OVFDM sliding window decoding bit-flipping algorithm block code spectral efficiency

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An efficient new object-based variational approach for MPEG video decoding

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ANNALS OF TELECOMMUNICATIONS 2000年第3-4期55卷 101-107页

作者： Jung, J Antonini, M Barlaud, M Univ Nice Sophia Antipolis Lab I3S CNRS UPRESA 6070 F-06903 Sophia Antipolis France

This paper presents a new decoding method for the improvement of visual quality in block-coned video sequences. A global decoding approach is performed to tackle artifacts die to compression, such as blocking effects and quantization noise, and simultaneously losses due to transmission, acquisition, or storage. It is based on the optimization of a criterion allowing independent and adapted restoration for the background of the scene and for each moving object. Experimental results on a MPEG sequence with simulated dropouts, and on an uncompressed hut very corrupted old movie are presented They demonstrate the efficiency of the proposed decoding method.

关键词： decoding image coding MPEG object oriented method variational calculus block code picture quality image restauration

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Achieving Near-Capacity Performance on Multiple-Antenna Channels with a Simple Concatenation Scheme

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IEEE TRANSACTIONS ON COMMUNICATIONS 2010年第4期58卷 1048-1059页

作者： Tran, Nghi H. Le-Ngoc, Tho Matsumoto, Tad Nguyen, Ha H. McGill Univ Dept Elect & Comp Engn Montreal PQ H3A 2T5 Canada Japan Adv Inst Sci & Technol Tokyo Japan Univ Oulu Ctr Wireless Commun Oulu Finland Univ Saskatchewan Dept Elect & Comp Engn Saskatoon SK S7N 0W0 Canada

This paper proposes a capacity-approaching, yet simple scheme for multi-input multiple-output (MIMO) channels. The proposed scheme is based on a concatenation of a mixture of short memory-length convolutional codes or repetition codes and a short, and simple rate-1 linear block code, followed by either 1-dimensional (1-D) anti-Gray or Gray mapping of quadrature phase-shift keying (QPSK) modulation. By interpreting the rate-1 code and the 1-D mapping as a multi-D mapping performed over multiple transmit antennas, the error performance is analyzed in two regions. In the error-floor region, a tight union bound and the corresponding design criterion on the asymptotic performance are derived. The bound provides a useful tool to predict the error performance at relatively low bit error rate (BER) values. Based on the obtained design criterion, an optimal rate-1 code for each 1-D mapping is then constructed to achieve the best asymptotic performance. In the turbo pinch-off region, by using extrinsic information transfer (EXIT) charts, the most suitable mixed codes are selected for both symmetric and asymmetric antenna configurations. It is demonstrated that the simple concatenation scheme can achieve a near-capacity performance over the MIMO channels. Furthermore, its error performance is shown to be comparable to that obtained by using well-designed irregular LDPC and RA codes, and therefore, the proposed scheme significantly outperforms a scheme employing a parallel concatenated turbo code. Simulation results in various cases are provided to verify the analysis.

关键词： Multiple-antenna channels capacity-approaching performance EXIT chart convolutional code repetition code block code anti-Gray mapping Gray mapping multi-dimensional mapping error bound

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Links between complexity theory and constrained block coding

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IEEE TRANSACTIONS ON INFORMATION THEORY 2002年第1期48卷 59-88页

作者： Stockmeyer, L Modha, DS IBM Corp Almaden Res Ctr Div Res San Jose CA 95120 USA

The goal of this paper is to establish links between computational complexity theory and the theory and practice of constrained block coding. In particular, the complexities of several fundamental problems in constrained block coding are precisely classified in terms of the existing complexity-theoretic structure. One type of problem studied is that of designing encoder and decoder circuits using minimum or approximately minimum hardware;for our purposes, an "input" to this problem is i) a deterministic, irreducible finite-state transition diagram (abbreviated DIF) defining a set of constrained binary sequences, and ii) a desired rate p : q. Several of these minimum-encoder and minimum-decoder problems are shown to be NP-hard, and more interestingly some are shown to be complete in the second and third levels of the polynomial hierarchy. Another fundamental problem is that of computing the maximum rate of a block code;that is, given a DIF and a codeword length q, find the maximum p such that a rate p : q block code exists for the constraint defined by the DIE This problem is shown to be NP#P-complete. Although it is not known whether NP#P contains problems of super-polynomial complexity, it lies "higher" in the complexity-class structure than N-P in the sense that it is possible, given current knowledge, that NP#P contains problems of super-polynomial complexity even if P = NP. Another question studied is whether maximum rate block codes can always be implemented by encoders and decoders of polynomial size. The answer to this question is shown to be closely related to whether the class #P lies "lower" in the complexity-class structure than currently believed-a proof of either answer would have major implications in complexity theory.

关键词： block code circuit size complexity constrained coding decoder encoder #P polynomial-time hierarchy rate

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Transparent Generic Framing Procedure (GFP): A protocol for efficient transport of block-coded data through SONET/SDH networks

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IEEE COMMUNICATIONS MAGAZINE 2002年第5期40卷 88-95页

作者： Gorshe, SS Wilson, T PMC-Sierra Nortel Networks

Generic Framing Procedure (GFP) is a new standard that has been developed to overcome data transport inefficiencies or deficiencies with the existing ATM and Packet over SONET/SDII protocols. Transparent GFP (GFP-T) is an extension to GFP developed to provide efficient low-latency support for high-speed WAN applications including storage area networks. Rather than handling data on a frame-by-frame (packet-by-packet) basis. GFP-T handles block-coded (e.g.. 813, 1013) character streams. This article describes the GFP protocol along, with technical considerations and applications for transparent GFP.

关键词： 813/1013 line code ATM block code block codes block-coded character streams block-coded data transport data communication efficient low-latency support generic framing procedure GFP protocol GFP-T high-speed WAN applications optical fibre networks packet switching packet transmission SONET SONET/SDH networks SONET/SDH protocols standard storage area networks synchronous digital hierarchy telecommunication standards transparent generic framing procedure transparent GFP transport protocols wide area networks

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Binary Grassmannian Weightbooks for MIMO Beamforming Systems

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IEEE TRANSACTIONS ON COMMUNICATIONS 2011年第2期59卷 388-394页

作者： Kim, Young Gil Beaulieu, Norman C. Univ Seoul Dept Elect & Comp Engn Seoul 130743 South Korea Univ Alberta Dept Elect & Comp Engn Edmonton AB T6G 2V4 Canada

Binary weightbooks for multiple-input multiple-output (MIMO) beamforming systems using quantized feedback are designed based on the Grassmannian beamforming criterion. It is shown that the Grassmannian criterion for binary weightbook design is to maximize the minimum Hamming distance of the corresponding block code. Thus, block codes that have large minimum Hamming distance can be used for binary weightbook design for MIMO beamforming systems using quantized feedback. The optimum binary weightbooks when the number of transmit antennas has value from two to six are tabulated.

关键词： block code fading channels MIMO systems quantized feedback transmitter diversity

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Groups of algebraic integers used for coding QAM signals

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IEEE TRANSACTIONS ON INFORMATION THEORY 1998年第5期44卷 1848-1860页

作者： Dong, XD Soh, CB Gunawan, E Tang, LZ Nanyang Technol Univ Sch Elect & Elect Engn Singapore 639798 Singapore Natl Univ Singapore Ctr Comp Singapore 119260 Singapore

Recently, linear block codes over Gaussian integers and Eisenstein integers were used for coding over two-dimensional signal space. Group of Gaussian integers with 2(2n) elements was constructed to code quadrature amplitude modulation (QAM) signals such that a differentially coherent method can be applied to demodulate the QAM signals. This paper shows that one subgroup of the multiplicative group of units in the algebraic integer ring of any quadratic number field with unique factorization, module the ideal (p(n)), can be used to obtain a QAM signal space of 2p(2n-2) points, where p is any given odd prime number. Furthermore, one subgroup of the multiplicative group of units in the quotient ring Z[omega]/(p(n)) can be used to obtain a QAM signal space of 6p(2n-2) points;one subgroup of the multiplicative group of units in the quotient ring Z[i]/(p(n)) can be used to obtain a QAM signal space of 4p(2n-2) points which is symmetrical over the quadrants of the complex plane and useful for differentially coherent detection of QAM signals;the multiplicative group of units in the quotient ring Z[omega]/(2(n)) can be used to obtain a QAM signal space of 3 . 2(2n-2) points, where i = root-1, omega = (-1 + root-3)/2 = (-1 + i root 3)/2, p is any given odd prime number, Z[i] and Z[omega] are, respectively, the Gaussian integer ring and the Eisenstein integer ring. These multiplicative groups can also be used to construct block codes over Gaussian integers or Eisenstein integers which are able to correct some error patterns.

关键词： block code differentially coherent detection multiplicative group of units QAM signal space

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Maximum Likelihood decoding rules for STBC: Generalized framework for detection and derivation of accurate upperbounds

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ANNALES DES TELECOMMUNICATIONS-ANNALS OF TELECOMMUNICATIONS 2004年第9-10期59卷 1228-1249页

作者： Mohammad-Khani, GR Ferre, G Cances, JP Meghdadi, V Univ Limoges ENSIL Grp Etud Syst Telecommun UMOP GESTECNRS FRE 2701 F-87068 Limoges France

In this paper we propose first a generalized framework for the Maximum Likelihood decoding of STBC. Using algebraic tools we then derive a new matrix model particularly well suited to the description of MIMO systems. After giving our particular detection rules we determine a new accurate upperbound for the BER performances of STBC transmitting schemes. Performance results are given which show the accuracy of the derived upperbound.

关键词： mobile radiocommunication decoding maximum likelihood block code space diversity space and time signal Rayleigh fading matrix method upper bound

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Chase-type and GMD coset decodings

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IEEE TRANSACTIONS ON COMMUNICATIONS 2000年第3期48卷 345-350页

作者： Fossorier, MPC Lin, S Univ Hawaii Dept Elect Engn Honolulu HI 96822 USA

In this letter, Chase decoding algorithms are generalized into a family of bounded distance decoding algorithms, so that the conventional Chase algorithm-2 and Chase algorithm-3 become the two extremes of this family. Consequently, more flexibility in the tradeoffs between error performance and decoding complexity is provided by this generalization, especially for codes with large minimum distance. Finally, this approach is extended to decoding with erasures.

关键词： block code Chase decoding reliability-based decoding GMD decoding soft-decision decoding

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