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IEEE Global Telecommunications Conference (GC Wkshps)

作者： Iscan, Onurcan Boehnke, Ronald Xu, Wen Huawei Technol Dusseldorf GmbH German Res Ctr Riesstr 25 D-80992 Munich Germany

ISBN: (纸本)9781538649206

A probabilistic shaping method for multi-level coding (MLC) is presented, where the transmitted symbols are forced to have a shaped non-uniform distribution. It is shown that shaping only a single bit-level suffices to compensate for most of the shaping loss on the fading channels. A polar code based implementation of the proposed scheme is presented, where shaping is performed by using a precoder at the transmitter without increasing the decoding complexity. Simulation results show that performance improvements can be obtained compared to BICM- and MLC-based polar coding without shaping on Rayleigh fading channels.

关键词： Polar codes fading channels multi-level coding probabilistic shaping

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A multi-level coding awareness model combined with network QoS on bitman-based graphic collaborative editing system

A multi-level coding awareness model combined with network Q...

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Conference on Convergent Technologies for the Asia-Pacific Region (TENCON 2003)

作者： Li, Y Bu, JJ Chen, C Xu, XH Zhejiang Univ Coll Comp Sci Hangzhou 310027 Zhejiang Peoples R China

ISBN: (纸本)0780381629

Workspace awareness is one of the key issues in real-time collaborative editing system, especially in bitmap-based graphic editing system. Because of the intrinsic characteristic of bitmap, the data stream need to be exchanged in the network will increase dramatically. On the other hand, different collaborators in one collaborative project may have different network environment. So it is irrational to deliver the same large data-stream to distinct receivers. In this paper, we propose a multi-level coding method, which encodes each bitmap operation into serveral different granularities. In addition, we also propose a self-adapted awareness model by combining the awareness model with network Qos. As a result, different collaborators receive different data-stream in different granularity.

关键词： groupware quality of service image coding bit-mapped graphics multi-level coding awareness model network QoS bitmap-based graphic collaborative editing system workspace awareness real-time collaborative editing systems bitmap-based graphic editing system data stream granularity groupware systems

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multi-level dirty paper coding

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IEEE COMMUNICATIONS LETTERS 2008年第6期12卷 456-458页

作者： Chung, Sae-Young Korea Adv Inst Sci & Technol Sch EECS Taejon 305701 South Korea

We propose multi-level coding and successive decoding for dirty paper coding (DPC) in the high signal-to-noise ratio (SNR) regime. We divide the channel code into two levels, the upper code interacting with the shaping code and the lower code that does not such that it is information lossless. Our code design is more intuitive for designing DPC in the high SNR regime. The design of the lower code becomes trivial since it does not interact with the shaping code anymore. The design of the upper code is also simplified since we can now assume binary signaling for the code. We evaluate the capacity of each level and design codes to approach the estimated capacity. We demonstrate a good performance can indeed be achieved by simulations using lowdensity parity-check (LDPC) codes at each level. Our best code is only 0.45 dB from the no-interference Gaussian capacity at the spectral efficiency of 3 b/s/Hz.

关键词： dirty paper coding multi-level coding lattices

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Zigzag-Coded Modulation for High-Speed Fiber Optical Channels

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JOURNAL OF OPTICAL COMMUNICATIONS AND NETWORKING 2012年第5期4卷 382-391页

作者： Kahveci, Salim Gong, Chen Wang, Xiaodong Karadeniz Tech Univ Dept Elect Elect Engn TR-61080 Trabzon Turkey Columbia Univ Dept Elect Engn New York NY 10027 USA

We propose new coded modulation schemes for ultra-high-speed optical transmission (e. g., 100 Gb/s and above) using component concatenated zigzag codes in combination with high-order digital modulation and coherent detection. In particular, we propose single-level coded modulation and multi-level coded modulation using concatenated zigzag codes. For single-level coded modulation, only one concatenated zigzag code is employed to encode the information bits, and Gray mapping is employed to map the coded bits to channel symbols. For multi-level coded modulation, the mapping bits are divided into several layers, and one component concatenated zigzag code is employed at each layer;the layers are decoded successively, and the decoded layers are used to assist the decoding of the subsequent layers. Furthermore, we propose a rate allocation scheme for the component concatenated zigzag codes and a parameter selection scheme for multi-level coded modulation. Simulation results demonstrate that single-level and multi-level coded systems with zigzag codes show up to 0.5 dB performance gain over structured low-density parity check codes.

关键词： multi-level coding multi-stage decoding Rate allocation Zigzag codes

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Low-Complexity Coded-Modulation for ISI-Constrained Channels

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IEEE TRANSACTIONS ON COMMUNICATIONS 2009年第6期57卷 1836-1846页

作者： Hormis, Raju Wang, Xiaodong Analog Devices Inc Somerset NJ 08873 USA Columbia Univ Dept Elect Engn New York NY 10027 USA

We propose a low-complexity PAM-based transmission scheme that is well suited for channels constrained by inter-symbol interference (ISI) and colored Gaussian noise. The scheme consists of coset-codes constructed on multi-dimensional lattices with a combination of low-density parity-check (LDPC) codes and classical Reed-Solomon (RS) codes. To approach the capacity of an ISI-constrained channel, the code is easy to employ in conjunction with spectral shaping, Tomlinson-Harashima precoding and decision-feedback equalization (DFE). The scheme performs within 2-2.5 dB of un-shaped channel capacity (the sphere-bound) at very low BER's, even with regular LDPC codes of modest block lengths. We investigate dense multidimensional lattices such as the Schlafli, Gosset, Barnes-Wall, and Leech lattices, besides simple one-dimensional lattices. Via the density evolution technique, we show that the lattices reduce the noise threshold of belief-propagation decoders. We investigate the practical application of the proposed schemes to 10G-Base-T, an emerging Ethernet standard over twisted-pairs at 10 Gbit/sec. A simple 1-dimensional scheme improves upon recent proposals by 0.5-1 dB at BER's approaching 10(-11), with half the LDPC coding complexity. multi-dimensional schemes are seen to reduce the complexity further.

关键词： Coset codes ISI LDPC multi-dimensional lattices precoding equalization multi-level coding 10G-Base-T DSL

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multi-level Distribution Matching

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IEEE COMMUNICATIONS LETTERS 2020年第9期24卷 2015-2019页

作者： Boehnke, Ronald Iscan, Onurcan Xu, Wen Huawei Technol Duesseldorf GmbH European Res Ctr D-80992 Munich Germany

A general distribution matching architecture based on a multi-level structure is presented. It allows to generate arbitrary symbol distributions using simple binary distribution matchers. This is particularly advantageous for large symbol alphabets, where non-binary distribution matching algorithms tend to have high complexity. Some examples for possible implementations are provided, and a specific realization based on polar codes, which enables joint shaping and channel coding for reliable data transmission with higher-order modulation, is discussed and evaluated in detail.

关键词： Decoding Labeling Complexity theory Reliability Entropy Channel coding Distribution matching probabilistic shaping multi-level coding polar codes

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Improved Hard Iterative Decoding (IHID) of multilevel Codes

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IEEE COMMUNICATIONS LETTERS 2013年第7期17卷 1443-1446页

作者： Naim, M. Ahsan Fonseka, John P. Dowling, Eric M. Univ Texas Dallas Dept Elect Engn Richardson TX 75080 USA Trellis Phase Commun Marshall TX USA

An improved hard iterative decoding (IHID) algorithm is presented to efficiently terminate hard iterations in the decoding of multi-level codes. The proposed terminating policy stops iterations as soon as a valid path on the super trellis is found thereby only running the minimum required number of iterations. The IHID decoding algorithm performs better than the conventional multi-stage decoding by reducing the effects of error multiplicity. Compared with known hard iterative decoding with fixed number of iterations, the IHID algorithm can significantly reduce decoding complexity and decoding delay.

关键词： multi-level coding iterative decoding interleaving path multiplicity multi-stage decoding

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Interference Alignment for the multiantenna Compound Wiretap Channel

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IEEE TRANSACTIONS ON INFORMATION THEORY 2011年第5期57卷 2976-2993页

作者： Khisti, Ashish Univ Toronto ECE Dept Toronto ON M1B 5P1 Canada

We study a wiretap channel model where the sender has transmit antennas and there are two groups consisting of J(1) and J(2) receivers respectively. Each receiver has a single antenna. We consider two scenarios. First we consider the compound wiretap model-group 1 constitutes the set of legitimate receivers, all interested in a common message, whereas group 2 is the set of eavesdroppers. We establish new lower and upper bounds on the secure degrees of freedom (d.o.f.). Our lower bound is based on the recently proposed real interference alignment scheme. The upper bound provides the first known example which illustrates that the pairwise upper bound used in earlier works is not tight. The second scenario we study is the compound private broadcast channel. Each group is interested in a message that must be protected from the other group. Upper and lower bounds on the d.o.f. are developed by extending the results on the compound wiretap channel.

关键词： Common message compound channels deterministic approximation information theoretic security interference alignment multi-level coding private broadcast channels wiretap channel

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Error-Correcting WOM Codes: Concatenation and Joint Design

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IEEE TRANSACTIONS ON INFORMATION THEORY 2019年第9期65卷 5529-5546页

作者： Solomon, Amit Cassuto, Yuval Technion Israel Inst Technol Viterbi Dept Elect Engn IL-3200003 Haifa Israel

We construct error-correcting write-once memory (WOM) codes that guarantee correction of any specified number of errors in q-level memories. The constructions use suitably designed short q-ary WOM codes and concatenate them with outer error-correcting codes over different alphabets using suitably designed mappings. With a new storage-efficiency measure, we call EC-rate and show that for common error types the codes save redundancy and implementation complexity over straightforward concatenation. In addition to constructions for guaranteed error correction, we extend the error-correcting WOM scheme to binary multi-level coding for random errors, and toward soft-decision decoding provide an efficient way to extract reliability information without using higher-precision readout.

关键词： WOM codes error-correcting WOM codes codes for memories concatenated codes multi-level coding coded modulation

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On the Impact of Highpass Filtering when using PAM-FDE for Visible Light Communication

On the Impact of Highpass Filtering when using PAM-FDE for V...

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IEEE Wireless Communications and Networking Conference (WCNC)

作者： Grobe, Liane Jungnickel, Volker Langer, Klaus-Dieter Haardt, Martin Wolf, Mike Heinrich Hertz Inst Nachrichtentech Berlin GmbH Fraunhofer Inst Telecommun Einsteinufer 37 D-10587 Berlin Germany Tech Univ Ilmenau Postfach 100565 D-98684 Ilmenau Germany

ISBN: (纸本)9781467398145

A next generation optical wireless communications standard is currently established, denoted as IEEE 802.15.7rl, targeting data rates between 1 Mbit/s and 10 Gbit/s. Selecting an appropriate transmission scheme is one of the critical tasks. Following this issue, this paper gives a review on PAM-FDE in VLC. Based on PAM-FDE laboratory measurements, we demonstrate the need to include highpass filtering into the propagation model. In this paper, numerical analyses investigate the impact of the resulting baseline wander on the performance. We include a multi-level 5S6S coding technique in order to prepare PAM-FDE for practice. Finally, research topics are summarized.

关键词： VLC PAM FDE highpass baseline wander DC-balance multi-level coding

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