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Two-Level Unequal Error Protection Scheme in Image Transmission System Using multilevel Codes in Rayleigh Fading Channel

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The Journal of China Universities of Posts and Telecommunications 2004年第Z1期11卷 55-61页

作者： LI Zuo-wei~1, YANG Yi-xian~1, YUAN Dong-feng~2, HU Zheng-ming~1 1.Information Security Center,Beijing University of Posts and Telecommunications, Beijing 100876, P.R. China 2.School of Information Science and Engineering, Shandong University, Jinan 250100, P.R. China Information Security Center Beijing University of Posts and Telecommunications Beijing 100876 P.R. China School of Information Science and Engineering Shandong University Jinan 250100 P.R. China

In this paper, we propose a novel Unequal Error Protection (UEP) scheme with two levels for image transmission using multilevel Codes (MLC). By providing the best protection for the most important data, the final recovered image quality is remarkably improved both in visual effect and in Peak Signal to Noise power Ratio (PSNR) performance.

关键词： rayleigh fading channel image transmission inequal error protection multilevel coding

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Bit-interleaved coded modulation with shaping

Bit-interleaved coded modulation with shaping

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2010 IEEE Information Theory Workshop, ITW 2010

作者： I Fabregas, Albert Guillen Martinez, Alfonso Department of Engineering University of Cambridge United Kingdom Centrum Wiskunde and Informatica Amsterdam Netherlands

ISBN: (纸本)9781424482641

The performance of bit-interleaved coded modulation (BICM) with shaping (i.e., non-equiprobable bit probabilities) is studied. For the AWGN channel, the rates achievable with BICM and shaping are practically identical to those of coded modulation or multilevel coding, virtually closing the gap that made BICM suboptimal in terms of information rates. © 2010 IEEE.

关键词： AWGN channel AWGN channels bit-interleaved coded modulation interleaved codes modulation multilevel coding shaping

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multilevel Coded Cooperation for Wireless Vehicular Networks

Multilevel Coded Cooperation for Wireless Vehicular Networks

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68th IEEE Vehicular Technology Conference

作者： Yilmaz, Mumtaz Yilmaz, Reyat Dokuz Eylul Univ Dept Elect & Elect Engn Izmir Turkey

ISBN: (纸本)9781424417223;9781424417216

At the physical layer of wireless vehicular networks, coded cooperation is a possible way of realizing uplink transmit diversity at the mobile vehicles equipped with single antenna. In this work, in order to increase the power and bandwidth efficiency, a multilevel coded cooperative system using orthogonal signalling is proposed. Orthogonal signalling not only enables transmission of both users data in single channel symbol but also provides independent detection at the receiver. We investigate the performance of the system by derivation of pairwise and bit error probabilities together with Monte-Carlo simulations.

关键词： Coded cooperation vehicular networks multilevel coding orthogonal signalling

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Block-Coded 16TAPSK and 16QAM for Generalized Differential Encoding

Block-Coded 16TAPSK and 16QAM for Generalized Differential E...

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12th International Conference on ITS Telecommunications (ITST)

作者： Lin, Tzu-Shiang Natl Cent Univ Dept Commun Engn Jhongli Taiwan

ISBN: (纸本)9781467330701;9781467348171

In this paper, we consider noncoherent block-coded QAM (quadrature-amplitude modulation) and TAPSK (twisted amplitude and phase shift keying) for generalized differential encoding. For noncoherent block-coded MPSK over continuous channels, rotating signal points of an entire codeword, such that the first symbol is the same as the last symbol of previously transmitted codeword and thus can be omitted, increase bandwidth efficiency. This method is called generalized differential encoding. Since noncoherent block-coded QAM/TAPSK proposed before cannot be applied to generalized differential encoding, in this paper, we modify the definition of noncoherent block-coded QAM/TAPSK and the bit labeling of signal points. Simulations of various examples of noncoherent block-coded QAM/TAPSK with generalized differential encoding are made and discussed as well. We find that if the block length is very small than 8, NBC-16TAPSK performs better than NBC-16QAM due to its large minimum noncoherent distance. However, if the block is longer than 8, NBC-16QAM has better error performance because the codewords with small noncoherent distances are rare.

关键词： Noncoherent detection block-coded modulation multilevel coding

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multilevel Polar-Coded PAM-8 with MSB Shaping over Turbulent FSO Communication Link

Multilevel Polar-Coded PAM-8 with MSB Shaping over Turbulent...

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2023 Asia Communications and Photonics Conference/2023 International Photonics and Optoelectronics Meetings, ACP/POEM 2023

作者： Yang, Weiying Liu, Xiaoyu Liu, Zhiyang Xiao, Shilin Shanghai Jiao Tong University The State Key Laboratory of Advanced Optical Communication System and Networks Shanghai200240 China

ISBN: (纸本)9798350312614

Thanks to the flexibility and adaptability of polar codes, a Free-space Optical (FSO) communication scheme combining it with probabilistic shaping (PS) and pulse amplitude modulation (PAM) is proposed to achieve capacity improvement in atmospheric turbulence (AT) channels. The proposed scheme generates a non-uniform probability distribution PAM-8 transmission symbol by a multilevel polar-coded modulation (MLPC) method equipped with the most significant bit (MSB) level shaping precoder. Under the selected turbulence conditions, it provides up to 1.09dB theoretical shaping gain of capacity at the specified information rate (AIR) of 1.859 bit/channel use and 0.82dB performance gain in block error rate. © 2023 IEEE.

关键词： FSO multilevel coding PAM8 Probabilistic Shaping Turbulence Channel

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Signalling enhancement on multilevel turbo codes

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INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS 2008年第7期21卷 791-798页

作者： Bayat, Oguz Shafai, Bahram Salehi, Masoud Ucan, Osman N. Osman, Onur Beykent Univ Elect & Commun Engn Dept TR-34500 Istanbul Turkey Northeastern Univ Dept Elect & Comp Engn Boston MA 02115 USA Istanbul Univ Elect & Elect Dept TR-34850 Istanbul Turkey Istanbul Commerce Univ TR-34378 Istanbul Turkey

The design of multilevel turbo codes using M-PSK is optimized to achieve a low bit error rate (BER). Unequal error protection is employed via group set partitioning in multi-stage decoding to minimize the error propagation and BER. Simulation results are performed under Gaussian and Rayleigh fading channels to depict the superiority of the new scheme. Copyright (C) 2008 John Wiley & Sons, Ltd.

关键词： multilevel coding turbo codes signal set partitioning transmission systems

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Blind equalization of multilevel turbo coded-continuous phase frequency shift keying over MIMO channels

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INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS 2007年第1期20卷 103-119页

作者： Osman, Onur Istanbul Commerce Univ TR-34378 Istanbul Turkey

In this paper, multilevel turbo coded-continuous phase frequency shift keying (MLTC-CPFSK) is introduced and its bit error performance in multiple input multiple output (MIMO) facling channels are investigated considering a blind maximum likelihood channel estimation. multilevel turbo coded signals with continuous phase modulation (CPM) provides low spectral occupancy and is Suitable for power and bandwidth-limited channels. Besides, antenna diversity is one of the best method to combat with multipath fading effects. The performance of 2LTC for 4-ary CPFSK over AWGN, Rician (for Rician channel parameter K = 10 dB) and Rayleigh channels are given for 1Tx-1 Rx, 2Tx-1 Rx and 2Tx-2Rx antenna configurations. Channel capacities of 2LTC- 4CPFSK signals are obtained as -5.26, -7.65 and -7.14dB for ITx-1 Rx, 2Tx-1 Rx and 2Tx-2Rx antenna configurations, respectively. Baum-Welch (BW) algorithm is used to estimate the channel parameters. Bit error probabilities of 2 level turbo coded 4 CPFSK (2LTC-4CPFSK) are drawn in the cases of no channel state information (CSI), BW estimation, and perfect CSI. Approximately 0.1 and 0.75 dB gains in E.,INO are obtained using BW channel estimator for Rician and Rayleigh channels, respectively. Therefore, MLTC-CPFSK with BW channel estimator has excellent performance in MIMO fading channels. Copyright (c) 2006 John Wiley & Sons, Ltd.

关键词： multilevel coding turbo codingiblind channel estimation continuous phase inodulation MIMO channels channel capacity

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Noncoherent coded modulation for fading channels

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AEU-INTERNATIONAL JOURNAL OF ELECTRONICS AND COMMUNICATIONS 2000年第6期54卷 399-411页

作者： Lampe, LHJ Fischer, RFH Univ Erlangen Nurnberg Lehrstuhl Nachrichtentech 2 D-91058 Erlangen Germany

Coded modulation for noncoherent transmission over slowly time-variant flat fading channels without channel state information is considered. We focus on differentially encoded M-ary PSK with multiple-symbol differential detection (MSDD). Interleaving of blocks of symbols is used as a compromise between the conflicting requirements of exploiting the channel coherence time and providing diversity for decoding. We study multilevel coding (MLC) which is perfectly matched to the overall vector channel. As already well-known for coherent transmission, properly designed MLC is proved to be asymptotically optimum in the noncoherent case, too. A favorable strategy for labeling of signal points is given. As a promising alternative to MLC, bit-interleaved coded modulation (BICM) is addressed. But since no Gray labeling is possible, BICM can only marginally benefit from MSDD. Conversely, in case of strict decoding delay constraints, MLC suffers from component codes with very short code length. To overcome this drawback, we propose hybrid coded modulation schemes, which are able to combine the advantages of MLC and BICM, respectively. For performance assessment, we evaluate both the achievable channel capacity and the random coding exponent associated with noncoherent coded modulation. Moreover, we show that in multilevel coding and multistage decoding (MSD) the complexity of MSDD can be reduced significantly. Remarkably, the performance gain of MSDD can be exploited almost completely with practically no increase in computational complexity compared to conventional differential detection.

关键词： multilevel coding bit-interleaved coded modulation flat fadig channel differential encoding multiple-symbol differential detectio random coding exponent

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Performance analysis of multilevel coded modulation system with finite interleaving for fading channel

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ELECTRONICS AND COMMUNICATIONS IN JAPAN PART III-FUNDAMENTAL ELECTRONIC SCIENCE 2001年第2期84卷 65-75页

作者： Kaneda, K Ogiwara, H Sasebo Natl Coll Technol Dept Control Engn Sasebo 8571193 Japan Nagaoka Univ Technol Dept Elect Engn Nagaoka Niigata 9402188 Japan

In order to analytically evaluate the characteristics of the multilevel coding method using finite interleaving for a fading communication channel, an evaluation method for coding performance is proposed. In this method, the error rate of PSK after passing through a fading communication channel in which the gain variations at different times are statistically not independent is approximated by a Markov model. The state transition probability and the transfer gain of the Markov model are optimized by the use of a genetic algorithm. Next, the characteristic evaluation equation of the multilevel coding method for this Markov approximation model is derived. In this derivation, the characteristic evaluation equation is derived in the following way. The generation probability of the error in each level is derived as a function of the number of generations of the states in the section of the coding length and the error rate is averaged by the state generation probability. With this evaluation equation, the error rate after decoding with finite interleaving is derived and the optimum coding method is clarified. (C) 2000 Scripta Technica, Electron Comm Jpn Pt 3, 84(2):65-75, 2001.

关键词： multilevel coding fading communication channel Markov model interleave

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multilevel Reed-Solomon Codes for PMR Channels

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IEEE TRANSACTIONS ON MAGNETICS 2016年第2期52卷

作者： Demirkan, Ismail Silvus, Gregory Istanbul Sehir Univ TR-34662 Istanbul Turkey Broadcom Corp Longmont CO 80503 USA

Reed-Solomon (RS) codes are commonly utilized in magnetic recording systems to correct error bursts. A soft-output Viterbi algorithm (SOVA) is a commonly used detector to provide soft information to error-correcting decoders. We propose a novel architecture of a multilevel interleaved RS coding scheme that not only provides better performance but also has less complexity than an equivalent RS code. This architecture implements an error event detector using the soft information generated by the SOVA detector. The performance and complexity of the decoding technique are compared with the well-known soft-decoding techniques, such as generalized minimum distance decoding and Chase decoding techniques.

关键词： Chase decoding error-correction coding generalized minimum distance (GMD) decoding interleaved coding multilevel coding perpendicular magnetic recording (PMR) Reed-Solomon (RS) codes soft-output Viterbi algorithm (SOVA)

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