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8th Microoptic Conference (MOC 01)

作者： Haeiwa, H Nakashima, H Kokubun, Y Masaki, A Toyooka, T Yokohama Natl Univ Grad Sch Engn Dept Elect & Comp Engn Hodogaya Ku Yokohama Kanagawa 2408501 Japan Nippon Mitsubishi Oil Corp Infomat & Devices R&D Grp Naka Ku Yokohama Kanagawa 2310815 Japan

In the current optical data storage, binary coding is used, in which mark and null states correspond to high and low levels of reflected light. In the binary coding, the capacity of recording information can be increased by minimizing the pit size and maximizing the track density. However, the minimization of pit size will reach a limit even if near-field optics are used. To overcome this limitation, we have proposed and demonstrated multilevel optical data storage by changing the pit depths of a birefringent film. In this method, the volume of stored information can be increased without increasing the pit density. multilevel pits with the width of 1 mum and with various depths were formed on a liquid crystalline polymer film with the birefringence of 0.20, and the phase difference between orthogonal polarizations was confirmed to be proportional to the depth of the pits.

关键词： optical data storage multilevel coding birefringence phase difference polarization state liquid crystalline film

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On the Design of MLC-LDPC-OFDM in DRM MF and HF Channels 6

On the Design of MLC-LDPC-OFDM in DRM MF and HF Channels

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6th International Conference on Wireless Communications and Signal Processing (WCSP)

作者： Liang, Yuan Zhang, Shulin Gu, Pinbiao Wu, Lenan Southeast Univ Sch Informat Sci & Engn Nanjing 210096 Jiangsu Peoples R China

ISBN: (纸本)9781479973392

Orthogonal Frequency Division Multiplexing (OFDM), aided by proper channel coding schemes, can realize very dependable transmission in fading channels. For the purpose of improving the performance of the OFDM based DRM digital AM broadcasting in MF and HF channels, this paper designs MLC-LDPC-OFDM transmission scheme that is suitable for MF and HF channels. The equivalent channel capacities of MLC-LDPC-OFDM with two different decoding strategies, namely IMSD and PDL, are analyzed, basing on which this paper redesigns the code rates of MLC. In addition, the calculation of likelihood ratio in LDPC decoding is modified according to channel models. The simulation results show that the proposed schemes have better performance than the existing ones in MF and HF channels.

关键词： OFDM Digital Radio Mondiale low density parity check codes multilevel coding equivalent channel capacity

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Reseaux de points flexibles pour modulations et codages a hautes efficacites spectrales

Reseaux de points flexibles pour modulations et codages a ha...

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作者： Carole Al Bechlawi

学位级别：博士

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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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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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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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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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