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International Conference on Wireless Communications and Signal Processing

作者： Chengjun Tang Ming Jiang Chunming Zhao Nat. Mobile Commun. Res. Lab. Southeast Univ. Nanjing China

ISBN: (纸本)9781467376884

In this paper, we study a hybrid free-space optical/radio-frequency (FSO/RF) communication system deploying protograph-based low-density parity-check (P-LDPC) codes. We use the protograph-based extrinsic information transfer (PEXIT) algorithm to accurately evaluate the system performance and employ the hybrid FSO/RF symbol mapping technique and the generalized variable degree matched mapping (G-VDMM) interleaver to enhance the performance. To make the optimization feasible and simpler for high-level modulation, we propose a much simpler but efficient design method: select a conventional Gray-labeled mapping scheme and then optimize the G-VDMM interleaver. Both numerical analyses and simulations verify that the performance of a hybrid FSO/RF system can be greatly improved by optimizing the symbol mapping and bit interleaving.

关键词： Gray codes interleaved codes modulation coding optical communication optical modulation optimisation parity check codes radiocommunication Gray-labeled mapping scheme P-LDPC coded hybrid FSO-RF communication system analysis P-LDPC coded hybrid FSO-RF communication system optimization design bit interleaving free-space optical communication system generalized variable degree matched mapping interleaver high-level modulation hybrid FSO-RF symbol mapping technique protograph-based extrinsic information transfer algorithm protograph-based low-density parity-check codes radio-frequency communication system symbol mapping Algorithm design and analysis Labeling modulation Numerical analysis Optimization Parity check codes Radio frequency parity check codes Map symbols bit interleaving Algorithm design and analysis interleaved codes Radiocommunication Gray codes modulation coding Numerical Analysis Optical modulation high-level modulation Optical communication radiofrequency Optimal design free-space optical communication

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An Adaptive Algorithm for Joint Data Detection and Channel Estimation for Meteor Burst Communications Based on Per-Survivor Processing

An Adaptive Algorithm for Joint Data Detection and Channel E...

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IEEE Global Communications Conference

作者： Zan Li Xiaojun Chen Yuquan Li Norman C. Beaulieu Mohammad S. Obaidat State Key Laboratory of Integrated Service Networks Xidian University China Electronics Systems Engineering Corporation Beijing School of Information and Communication Engineering Beijing University of Posts and Telecommunications Department of Computer and Information Science at Fordham University

ISBN: (纸本)9781479959532

For meteor burst communications (MBC), although per-survivor processing (PSP) based on joint data and channel estimation provides superior performance and robustness for meteor burst communications (MBC), great computational complexity constrains its application in practice. On this occasion, a dimension-down PSP (D-PSP) algorithm and a adaptive state reduction of PSP (ASRP) algorithm are proposed to curve this problem in this paper. On the basis of this, the adaptive state reduction using a dimension-down PSP (ADPSP) is proposed to combine the advantages of D-PSP and ASRP, which reduces the computational time and memory size for exponentially decaying meteor burst channels and makes maximum likelihood sequence detection (MLSD) possible for adaptive data transmission. Simulation results are presented to validate the theoretical analysis. It is shown that deploying the proposed ADPSP algorithm can achieve a good tradeoff between performance and computational complexity dynamically, and provide reliable data transmission for MBC systems with adaptive coding and modulation.

关键词： Adaptive modulation and coding MBC MLSD Per-survivor processing maximum likelihood sequence detection data detection channel estimation mecarzole MBC State reduction modulation coding REG1A gene Postsynaptic Potentials BPIFA2 gene RIDA gene data transmission dimensions Self tuning Adaptive algorithms

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Multilevel coding for the Full-Duplex Relay Channel

Multilevel Coding for the Full-Duplex Relay Channel

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IEEE Global Communications Conference

作者： Ahmed Attia Abotabl Aria Nosratinia Department of Electrical Engineering University of Texas at Dallas

ISBN: (纸本)9781479959532

The overwhelming majority of the large literature on coding for the relay channel has been dedicated to the low-SNR regime (binary signaling) and the half-duplex scenario. For non-binary full-duplex signaling, important challenges remain in the simultaneous design of coded modulation at the source and relay. Part of the difficulty is to design the codes with the requisite correlation prescribed by theory. This paper proposes a systematic code design methodology for the relay channel via multilevel coding (MLC). The main difficulty was that a straight-forward extension of the chain rule MLC decomposition, as was previously used in the point-to-point MLC, would result in many dependencies between the coded layers of the source and relay. A key contribution of this paper is showing that MLC joint source/relay code design can be implemented via standard binary code design procedures. Specifically, we outline a design process where the correlation between the source and relay codes are implemented purely via pairwise correlations between the binary codes of source and relay at each layer, without any other inter-layer correlations. Moreover, a specific design example is provided via a simple XOR operation on two conventionally designed codes. Numerical results show excellent performance for the proposed scheme.

关键词： relay channel Multilevel coding relay microprocessor logic circuit MLC1 gene design process binary code FULL DUPLEX exclusive-OR function Codes Pairwise error probability modulation coding

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A novel approach to dictionary construction for automatic modulation classification

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JOURNAL OF THE FRANKLIN INSTITUTE-ENGINEERING AND APPLIED MATHEMATICS 2014年第5期351卷 2991-3012页

作者： Dulek, B. Ozdemir, O. Varshney, P. K. Su, W. Hacettepe Univ Dept Elect & Elect Engn TR-06800 Ankara Turkey ANDRO Computat Solut Rome NY 13440 USA Syracuse Univ Dept Elect Engn & Comp Engn Syracuse NY 13244 USA Army CERDEC Aberdeen Proving Ground MD USA

In almost all the work owned out in the area of automatic modulation classification (AMC), the dictionary of all possible modulations that can occur is assumed to be fixed and given. In this paper, we consider the problem of discovering the unknown digital amplitude-phase modulations when the dictionary is not given. A deconvolution based framework is proposed to estimate the distribution of the transmitted symbols, which completely characterizes the underlying signal constellation. The method involves computation of the empirical characteristic function (ECF) from the received signal samples, and employing constrained least squares (CLS) filtering in the frequency domain to reveal the unknown symbol set. The decoding of the received signals can then be carried out based on the estimate of the signal constellation. The proposed method can be implemented efficiently using fast Fourier transform (FFT) algorithms. In addition, we show that the distribution estimate of the transmitted symbols can be refined if the signal constellation is known to satisfy certain symmetry and independence properties. (C) 2014 The Franklin Institute. Published by Elsevier Ltd. All rights reserved.

关键词： AUTOMATIC control modulation coding EMPIRICAL research CHARACTERISTIC functions FAST Fourier transforms SYMMETRY (Mathematics)

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Backscatter Communication and RFID: coding, Energy, and MIMO Analysis

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IEEE TRANSACTIONS ON COMMUNICATIONS 2014年第3期62卷 770-785页

作者： Boyer, Colby Roy, Sumit Univ Washington Dept Elect Engn Seattle WA 98195 USA

Radio Frequency IDentification (RFID) is intended to supplant legacy (optical) bar code scanning technology found in many logistic and retail applications. RFID is distinguished by inexpensive, low power and compact form factor tags, whose longevity and efficacy are predicated on using passive communication techniques and on-tag power harvesting. Such tags employ backscatter modulation, which does not require any active RF components. As a result, backscatter has become an attractive design choice for short-range communications in power constrained wireless sensor networking scenarios. The purpose of this work is two-fold. First, it aims to expose backscatter communication as an emerging topic to a communication systems-theoretic audience. Since backscatter modulation and on-tag power harvesting efficiency are coupled, it is necessary to re-examine notions of power and spectral efficiency from an energy-constraint perspective;this leads to novel coded modulation schemes for future RFID systems. Further, we investigate RFID MIMO systems where the channel fading encountered has different statistics than the classical Rayleigh fading model. In turn, the trade off between diversity order and spatial multiplexing gains are distinct from wide-area MIMO.

关键词： Radio communication scattering RFID tags MIMO modulation modulation coding fading wireless sensor networks

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Coded modulation for Fiber-Optic Networks [Toward better tradeoff between signal processing complexity and optical transparent reach]

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IEEE SIGNAL PROCESSING MAGAZINE 2014年第2期31卷 93-103页

作者： Beygi, Lotfollah Agrell, Erik Kahn, Joseph M. Karlsson, Magnus Chalmers Univ Technol Gothenburg Sweden Stanford Univ Stanford CA 94305 USA Crawford Hill Lab AT&T Bell Labs Holmdel NJ USA Univ Calif Berkeley Fac Elect Engn Berkeley CA USA

In this tutorial, we study the joint design of forward error correction (FEC) and modulation for fiber-optic communications. To this end, we use an information-theoretic design framework to investigate coded modulation (CM) techniques for standard additive white Gaussian noise (AWGN) channels and fiber-optic channels. This design guideline helps us provide a comprehensive overview of the CM schemes in the literature. Then, by invoking recent advances in optical channel modeling for nondispersion-managed links, we discuss two-dimensional (2-D) and four-dimensional (4-D) CM schemes. Moreover, we discuss the electronic computational complexity and hardware constraints of CM schemes for optical communications. Finally, we address CM schemes with signal shaping and rate-adaptation capabilities to accommodate the data transmission scheme to optical links with different signal qualities.

关键词： Optical Fibers AWGN Fiber optic networks Optical links Scheme Meltdown data transmission modulation coding signal shaping Optical fibre communication channel modeling

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Low-complexity iterative interference cancellation multiuser detection based on channel selection and adaptive transmission

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IET COMMUNICATIONS 2014年第11期8卷 1988-1995页

作者： Chen, Min Burr, Alister G. Univ York Dept Elect York YO10 5DD N Yorkshire England

In this study, a new iterative interference cancellation (IIC) multiuser detection method is proposed for overloaded multiple-input multiple-output (MIMO) coded orthogonal frequency division multiplexing systems. A channel analyser is used to detect those channels for which the IIC detector will not converge. For these we propose two adaptive methods to enable detection. The first is to use a lower code rate for these channels. The second is to divide the transmitters into several groups which transmit in separate slots. Low-complexity matched filter is applied, and both successive interference cancellation and parallel interference cancellation are considered for interference reconstruction. The simulation results show that the proposed technique can achieve near-optimum bit error rate performance and optimum frame error rate performance, with lower complexity than optimum maximum-likelihood methods.

关键词： interference suppression iterative methods multiuser detection channel estimation MIMO communication OFDM modulation modulation coding channel coding radio transmitters matched filters error statistics signal reconstruction OFDM frame error rate bit error rate interference reconstruction parallel interference cancellation successive interference cancellation low-complexity matched filter transmitters lower code rate channel detection channel analyser coded orthogonal frequency division multiplexing system multiple input multiple output overloaded MIMO IIC multiuser detection method adaptive transmission method channel selection iterative interference cancellation

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Online log-likelihood ratio scaling for robust turbo decoding

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IET COMMUNICATIONS 2014年第2期8卷 217-226页

作者： El-Khamy, Mostafa Wu, Jinhong Lee, Jungwon Kang, Inyup Samsung Res Amer Mobile Solut Lab San Diego CA 92121 USA

Optimal iterative log-MAP decoding of turbo codes requires accurate knowledge of the operating signal-to-noise ratio (SNR). However, the SNR information, available at practical decoders for bit-interleaved coded modulation systems, such as the third generation partnership project high-speed packet access and long-term evolution wireless cellular systems, may be inaccurate. In this study, two decoder architectures for improved turbo decoding in the presence of SNR mismatch are proposed. The SNR-mismatch aware turbo decoder selects the decoder which is estimated to have the best performance at the current mismatch, according to the test criterion. The SNR-mismatch compensated turbo decoder provides a more accurate estimation of the noise variance and concurrently scales the channel and the decoder log-likelihood ratios (LLRs) to continue decoding. Two different methods are proposed to find the optimal scaling factors online, one on the symbol level and the other on the bit level. This study shows that online LLR scaling, without prior knowledge about the noise mismatch statistics, can result in near-optimal turbo decoding regardless of the initial SNR mismatch.

关键词： iterative decoding maximum likelihood decoding modulation coding radiocommunication turbo codes online log likelihood ratio scaling robust turbo decoding optimal iterative log-MAP decoding turbo codes decoder log-likelihood ratio signal-to-noise ratio mismatch decoder architecture bit-interleaved coded modulation systems

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Unequal error protection by partial superposition transmission using low-density parity-check codes

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IET COMMUNICATIONS 2014年第13期8卷 2348-2355页

作者： Huang, Kechao Liang, Chulong Ma, Xiao Bai, Baoming Sun Yat Sen Univ Dept Elect & Commun Engn Guangzhou 510275 Guangdong Peoples R China Xidian Univ ISN State Key Lab Xian 710071 Peoples R China

In this study, the authors consider designing low-density parity-check (LDPC) coded modulation systems to achieve unequal error protection (UEP). They propose a new UEP approach by partial superposition transmission (PST) called UEP-by-PST. In the UEP-by-PST system, the information sequence is distinguished as two parts, the more important data (MID) and the less important data (LID), both of which are coded with LDPC codes. The codeword that corresponds to the MID is superimposed on the codeword that corresponds to the LID. The system performance can be analysed by using discretised density evolution. Also proposed in this study is a criterion from a practical point of view to compare the efficiencies of different UEP approaches. Numerical results show that, over both additive white Gaussian noise channels and uncorrelated Rayleigh fading channels, (i) UEP-by-PST provides higher coding gain for the MID compared with the traditional equal error protection approach, but with negligible performance loss for the LID;and (ii) UEP-by-PST is more efficient with the proposed practical criterion than the UEP approach in the digital video broadcasting system.

关键词： parity check codes error correction codes modulation coding AWGN channels channel coding Rayleigh channels digital video broadcasting error statistics low density parity check LDPC coded modulation systems unequal error protection UEP approach partial superposition transmission UEP-by-PST system information sequence more important data MID less important data LID codeword discretised density evolution additive white Gaussian noise channels uncorrelated Rayleigh fading channels digital video broadcasting system

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Joint detection-decoding of majority-logic decodable non-binary low-density parity-check coded modulation systems: an iterative noise reduction algorithm

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IET COMMUNICATIONS 2014年第10期8卷 1810-1819页

作者： Zhao, Shancheng Wang, Xuepeng Wang, Teng Bai, Baoming Ma, Xiao Sun Yat Sen Univ Dept Elect & Commun Engn Guangzhou 510275 Guangdong Peoples R China Xidian Univ State Key Lab ISN Xian 710071 Peoples R China

In this study, the authors present a low-complexity iterative joint detection-decoding algorithm for majority-logic decodable non-binary low-density parity-check (LDPC) coded modulation systems. In the proposed algorithm, a hard-in-hard-out decoder is combined with a hard-decision signal detector in an iterative manner. Each iteration consists of five phases. Firstly, the detector makes hard decisions based on the iteratively updated 'received' signals;secondly, these hard decisions are distributed via variable nodes to check nodes;thirdly, check nodes compute hard extrinsic messages;fourthly, each variable node counts hard extrinsic messages from its adjacent check nodes and feeds back to the detection node the symbol with the most votes as well as the difference between the most votes and the second most votes;finally, these feedbacks are used to shift each 'received' signal point along an estimated direction to possibly reduce noise. The proposed algorithm requires only integer operations and finite field operations and consequently can be implemented with simple combinational logic circuits in practical systems. Simulation results show that the proposed algorithm performs well and hence serves as an attractive candidate for trading off performance against complexity for majority-logic decodable non-binary LDPC codes.

关键词： noise reduction algorithm Vote received signal Ganglia Parity check Iterative modulation coding low density parity check codes

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