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diversity coding in Two-Connected Networks

IEEE-ACM TRANSACTIONS ON NETWORKING 2017年第4期25卷 2308-2319页

作者： Babarczi, Peter Tapolcai, Janos Pasic, Alija Ronyai, Lajos Berczi-Kovacs, Erika R. Medard, Muriel Budapest Univ Technol & Econ MTA BME Future Internet Res Grp H-1117 Budapest Hungary Hungarian Acad Sci Inst Comp Sci & Control H-1111 Budapest Hungary Budapest Univ Technol & Econ H-1117 Budapest Hungary Eotvos Lorand Univ Dept Operat Res H-1117 Budapest Hungary MIT Elect Res Lab Cambridge MA 02139 USA

In this paper, we propose a new proactive recovery scheme against single edge failures for unicast connections in transport networks. The new scheme is a generalization of diversity coding where the source data AB are split into two parts A and B and three data flows A, B, and their exclusive OR (XOR) A circle plus B are sent along the network between the source and the destination node of the connection. By ensuring that two data flows out of the three always operate even if a single edge fails, the source data can be instantaneously recovered at the destination node. In contrast with diversity coding, we do not require the three data flows to be routed along three disjoint paths;however, in our scheme, a data flow is allowed to split into two parallel segments and later merge back. Thus, our generalized diversity coding (GDC) scheme can be used in sparse but still two-connected network topologies. Our proof improves an earlier result of network coding, by using purely graph theoretical tool set instead of algebraic argument. In particular, we show that when the source data are divided into two parts, robust intra-session network coding against single edge failures is always possible without any in-network algebraic operation. We present linear-time robust code construction algorithms for this practical special case in minimal coding graphs. We further characterize this question, and show that by increasing the number of edge failures and source data parts, we lose these desired properties.

关键词： Robust network coding diversity coding single edge failures instantaneous recovery

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diversity coding-based survivable routing with QpS and differential delay bounds

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OPTICAL SWITCHING AND NETWORKING 2017年第Part2期23卷 118-128页

作者： Pasic, Alija Babarczi, Peter Korosi, Attila Budapest Univ Technol & Econ MTA BME Future Internet Res Grp Budapest Hungary Budapest Univ Technol & Econ MTA BME Informat Syst Res Grp Budapest Hungary

Survivable routing with instantaneous recovery gained much attention in the last decade, as in optical backbone networks even the shortest disruption of a connection may cause tremendous loss of data. Recently, strict delay requirements emerge with the growing volume of multimedia and video streaming applications, which have to be ensured both before and after a failure. diversity coding provides a nice trade-off between the simplicity of dedicated protection and bandwidth-efficiency of network coding to ensure instantaneous recovery for the connections. Hence, in this paper we thoroughly investigate the optimal structure of diversity coding-based survivable routing, which has a well-defined acyclic structure of subsequent paths and disjoint path-pairs between the communication end-points. We define the delay of these directed acyclic graphs, and investigate the effect of Quality-of-Service and differential delay bounds on the solution cost. Complexity analysis and integer linear programs are provided to solve these delay aware survivable routing problems. We discuss their approximability and provide some heuristic algorithms, too. Thorough experiments are conducted to demonstrate the benefits of diversity coding on randomly generated and real-world optical topologies. (C) 2016 Elsevier B.V. All rights reserved.

关键词： Survivable routing Delay-aware routing QoS routing diversity coding Instantaneous recovery

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diversity coding for subcarrier multiplexing on multimode fibers

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IEEE TRANSACTIONS ON COMMUNICATIONS 2003年第9期51卷 1546-1553页

作者： Kanprachar, S Jacobs, I Naresuan Univ Dept Elect & Comp Engn Phitsanulok 65000 Thailand Virginia Polytech Inst & State Univ Bradley Dept Elect & Comp Engn Blacksburg VA 24061 USA

The bandwidth-distance product limitations of multimode fiber caused by intermodal dispersion may be exceeded by using subcarrier multiplexing. Since there are deep nulls in the frequency response within the frequency band of interest, it is necessary to either adaptively avoid these frequencies or to use an appropriate coding technique. We consider both the case of using a training sequence to identify the subcarriers to be discarded, and diversity coding in which the information may be recovered in the presence of the loss of a fixed number of subcarriers. Simulation results indicate that diversity coding, which is less complex than the use of training sequences, provides very good performance over a wide range of channel conditions.

关键词： diversity coding multimode fibers subcarrier multiplexing

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diversity coding for Instantaneous Link Recovery in Millimeter Wave Communications

Diversity Coding for Instantaneous Link Recovery in Millimet...

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IEEE International Symposium on Signal Processing and Information Technology (ISSPIT)

作者： Jasim, Mohammed Aldalbahi, Adel Valparaiso Univ Dept Elect & Comp Engn Valparaiso IN 46383 USA King Faisal Univ Dept Elect & Comp Engn Al Hasa Saudi Arabia

ISBN: (纸本)9781538675687

Millimeter Wave systems face significant challenges for robust signal transmission in the presence of aggregated path loss and penetration losses. Namely, once the link between the mobile and base stations is successfully established, i.e., based upon initial access schemes that determine the optimum beamforming and combing vectors at which the optimum signal level is detected. However, the signal associated with the optimum link can rapidly degrade due to increased obstacles in the link of various densities and sizes. This yields in reduced signal levels and link failure, consequently resulting in communication loss during control-or user-planes. This paper presents efficient link recovery scheme based upon diversity coding for multi-beam transmissions to overcome blockage effects. The proposed scheme features near-instantaneous link recovery times without the need for repeated beam search over all spatial directions, as compared to traditional recovery schemes that perform exhaustive and iterative beam to determine the new optimum direction.

关键词： Millimeter wave diversity coding link maintenance link recovery circular arrays hybrid beamforming recovery times

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Distributed Multilevel diversity coding

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IEEE TRANSACTIONS ON INFORMATION THEORY 2015年第11期61卷 6368-6384页

作者： Xiao, Zhiqing Chen, Jun Li, Yunzhou Wang, Jing Tsinghua Univ Dept Elect Engn Beijing 100084 Peoples R China McMaster Univ Dept Elect & Comp Engn Hamilton ON L8S 4K1 Canada Tsinghua Univ Res Inst Informat Technol Beijing 100084 Peoples R China

In distributed multilevel diversity coding, K correlated sources (each with K components) are encoded in a distributed manner such that, given the outputs from any alpha encoders, the decoder can reconstruct the first alpha components of each of the corresponding alpha sources. For this problem, the optimality of a multilayer Slepian-Wolf coding scheme based on binning and superposition is established when K <= 3. The same conclusion is shown to hold for general K under a certain symmetry condition, which generalizes a celebrated result by Yeung and Zhang.

关键词： Data compression diversity coding entropy inequality Lagrange multiplier linear programming rate region Slepian-Wolf superposition

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On symmetrical multilevel diversity coding

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IEEE TRANSACTIONS ON INFORMATION THEORY 1999年第2期45卷 609-621页

作者： Yeung, RW Zhang, Z Chinese Univ Hong Kong Dept Informat Engn Hong Kong NT Peoples R China Univ So Calif Dept Elect Engn Syst Inst Commun Sci Los Angeles CA 90089 USA

Symmetrical multilevel diversity coding with independent data streams has recently been studied by Roche et al., and the admissible coding rate region was determined for the case of three levels. In particular, it was shown that coding by superposition is optimal, which means that optimality can be achieved by very simple coding. However, it is very difficult to generalize their proof to an arbitrary number of levels, In this paper, we use a new approach to study this problem, and we show that coding by superposition is optimal for symmetrical multilevel diversity coding in general, We also discuss how our result can be applied when the source consists of correlated data streams. The techniques we use are new in multiuser information theory, and our work sheds some light on the standing problem of characterizing those multilevel diversity coding systems for which coding by superposition is optimal.

关键词： diversity coding multilevel systems multiterminal source coding multiuser information theory

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MULTILEVEL diversity coding WITH DISTORTION

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IEEE TRANSACTIONS ON INFORMATION THEORY 1995年第2期41卷 412-422页

作者： YEUNG, RW Chinese Univ of Hong Kong Shatin Hong Kong

In a diversity coding System, an information source is encoded by a number of encoders. There are a number of decoders, each of which can access a certain subset of the encoders. In this paper, we study a diversity coding problem in which there are two levels of decoders. The reconstructions of the source by decoders within the same level are identical, and are subject to the same distortion criterion. Our results imply a principle of superposition when the source consists of two independent data streams. Practical codes achieving zero error can easily be constructed for this special case. A class of open problems on this topic is also suggested.

关键词： MULTITERMINAL SOURCE coding diversity coding FAULT TOLERANCE PRINCIPLE OF SUPERPOSITION

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Performance evaluation of DS/CDMA scheme with diversity coding and MUI cancellation over fading multipath channel

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IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES 1996年第12期E79A卷 1994-2001页

作者： Saifuddin, A Kohno, R Faculty of Engineering Yokohama National University Yokohama-shi 240 Japan

This paper evaluates the performance of DS/CDMA with diversity coding and multiuser interference (MUI) cancellation in fading multipath channel. The diversity technique considered in this paper, is different from the conventional scheme and transmits different information over different channels. It is shown that, this diversity scheme performs better than conventional diversity scheme, and when combined with MUI cancellation provides significant performance improvement. Effects of partial band jamming on the system are also considered.

关键词： diversity coding multiuser interference cancellation fading

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Minimum Cost Survivable Routing Algorithms for Generalized diversity coding

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IEEE-ACM TRANSACTIONS ON NETWORKING 2020年第1期28卷 289-300页

作者： Pasic, Alija Babarczi, Peter Tapolcai, Janos Berczi-Kovacs, Erika R. Kiraly, Zoltan Ronyai, Lajos Budapest Univ Technol & Econ MTA BME Future Internet Res Grp H-1111 Budapest Hungary Budapest Univ Technol & Econ BME Dept Telecommun & Media Informat MTA BME Informat Syst Res Grp H-1111 Budapest Hungary Eotvos Lorand Univ Dept Operat Res H-1053 Budapest Hungary Eotvos Lorand Univ MTA ELTE Egervary Res Grp Combinatorial Optimizat H-1053 Budapest Hungary Eotvos Lorand Univ Dept Comp Sci H-1053 Budapest Hungary Inst Comp Sci & Control H-1111 Budapest Hungary Budapest Univ Technol & Econ BME Dept Algebra H-1111 Budapest Hungary

Generalized diversity coding is a promising proactive recovery scheme against single edge failures for unicast connections in transport networks. At the source node, the user data is split into two parts, and their bitwise XOR is computed as a third redundancy sub-flow. In order to guarantee instantaneous failure recovery without costly node upgrades, the network must ensure that any two of the three sub-flows reach the destination node in case of a single edge failure only by allowing flow duplication or merging identical flows, and avoiding any coding operation in the core network. In this paper, we investigate the corresponding routing problem to calculate capacity-efficient routes for these sub-flows. We propose a polynomial-time algorithm for topologies without capacity constraints on the links and without capability limitations of the nodes. We show that with node limitations the presented algorithm (as well as a minimum cost disjoint path-pair) provides a 4/3-approximation for the routing problem. Furthermore, we formulate an integer linear program to provide a minimum cost solution with arbitrary constraints in general graphs and we propose a polynomial-time algorithm in directed acyclic graphs. Our simulation results suggest that with upgrading only a small set of core network nodes with flow duplication and merging capabilities most of the benefits of generalized diversity coding can be achieved.

关键词： Survivable routing incremental deployment diversity coding instantaneous recovery transport networks

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Symmetrical multilevel diversity coding

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IEEE TRANSACTIONS ON INFORMATION THEORY 1997年第3期43卷 1059-1064页

作者： Roche, JR Yeung, RW Hau, KP CHINESE UNIV HONG KONG DEPT INFORMAT ENGN SHATIN NT HONG KONG

Multilevel diversity coding was introduced in recent work by Roche and Yeung. In a multilevel diversity coding system, an information source is encoded by a number of encoders. There is a set of decoders, partitioned into multiple levels, with each decoder having access to a certain subset of the encoders. The reconstructions of the source by decoders within the same level are identical and are subject to the same distortion criterion. Inspired by applications in computer communication and fault-tolerant data retrieval, we study a multilevel diversity coding problem with three levels for which the connectivity between the encoders and decoders is symmetrical. We obtain a single-letter characterization of the coding rate region and show that coding by superposition is optimal for this problem. Generalizing to a symmetrical problem with an arbitrary number of levels, we derive a tight lower bound on the coding rate sum.

关键词： coding by superposition diversity coding fault-tolerance multiterminal source coding

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