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Concatenated bit-interleaved coded modulation and orthogonal space-time block codes over fading channels

IET COMMUNICATIONS 2009年第8期3卷 1354-1362页

作者： Teimouri, M. Hedayat, A. Shiva, M. Univ Tehran Sch Elect & Comp Engn Ctr Excellence Appl Electromagnet Syst Tehran 14399 Iran Navini Networks Richardson TX 75082 USA

The authors analyse concatenated bit-interleaved coded modulation and orthogonal space-time block codes (OSTBC) over fading channels in the absence and presence of channel state information (CSI) in receiver. The authors derive analytical expressions for bit and frame error probabilities based on which corresponding designing rules are proposed. The analytical results are for arbitrary rate of constituent STBC and arbitrary convolutional code, and for CSI-aware receiver is for any number of transmit and receive antennas. Simulation results are presented to confirm the validity of the proposed designing rules. Moreover, the simulation results show that the proposed system outperforms concatenated trellis coded modulation and OSTBC.

关键词： TRANSMITTING Orthogonal Simulation results trellis coded modulation Fading channels Block codes modulation coding Bit interleaved coded modulation

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Power reduction on QPSK modulation codings for geopositioning application using LEO satellites

Power reduction on QPSK modulation codings for geopositionin...

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SBMO/IEEE MTT-S International Conference on Microwave and Optoelectronics (IMOC)

作者： Carlos Nazareth Motta Marins Pierre Kaufmann Antônio Alves Ferreira Marcelo Carneiro de Paiva Jacobus W. Swart Adonias Costa da Silveira National Institute of Telecommunications – Inatel Campinas State University – Unicamp Santa Rita do Sapucaí MG Brazil National Institute of Telecommunications Inatel State University of Campinas-UNICAMP Sao Paulo Brazil National Institute of Telecommunications – Inatel Santa Rita do Sapucaí MG Brazil CTI – Center for Information Technology “Renato Archer” Campinas SP Brazil National Institute of Telecommunications-INATEL-Brazil Santa Rita do Sapucai Minas Gerais Brazil National Institute of Telecommunications – Inatel Campinas State University – Unicamp São Paulo SP Brazil CTI - Center for Information Technology SP Brazil

Minimum transmission power using transponders in low earth orbit satellite is a major requirement for the new geo-positioning system, known as Geolocal. It utilises a repeater in space and ground-based precise geodetic reference bases. We discuss and compare two digital codings on the QPSK (quadrature phase shift keying) modulation: concatenated Reed-Solomon/Convolutional coding and concatenated BCH (Bose-Chaudhuri-Hocquenghem) with LDPC (Low Density Parity Code). We show that the latter brings 8 dB power gain on the whole two-way ground to satellite link allowing a reduction in the power requirements on the small platforms carrying the transponders.

关键词： Quadrature phase shift keying modulation coding Low earth orbit satellites Transponders Concatenated codes Repeaters Phase modulation Digital modulation Reed-Solomon codes Convolutional codes

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Enhanced Simultaneous Distributed Strain and Temperature Fiber Sensor Employing Spontaneous Brillouin Scattering and Optical Pulse coding

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IEEE PHOTONICS TECHNOLOGY LETTERS 2009年第7期21卷 450-452页

作者： Soto, Marcelo A. Bolognini, Gabriele Di Pasquale, Fabrizio Scuola Super Sant Anna I-56124 Pisa Italy

In this work, we propose the use of optical pulse coding techniques for simultaneous strain and temperature sensing based on spontaneous Brillouin scattering. Optical pulse coding provides a significant receiver signal-to-noise ratio enhancement, allowing for accurate Brillouin intensity and frequency shift measurements at low peak power levels. Due to the cross-sensitivity of these two parameters on both temperature and strain, optical pulse coding improves the temperature and strain resolution and sensing range with respect to Brillouin sensors operating with conventional single-pulses at the same peak power level. The proposed technique provides a high-performance cost-effective solution avoiding the use of high peak power levels.

关键词： Brillouin scattering modulation coding optical fiber measurement optical time-domain reflectometry (OTDR)

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Adaptive modulation for limited diversity fading channels

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IET COMMUNICATIONS 2009年第10期3卷 1675-1682页

作者： Nagaraj, S. San Diego State Univ Dept Elect & Comp Engn San Diego CA 92182 USA

In this study, the authors propose a novel technique for adaptive modulation over limited diversity fading channels with channel state information at the transmitter. Limited diversity channels such as those encountered in indoor orthogonal frequency division multiplexing systems are characterised by the fact that achievable diversity orders are limited by the channel and not by code-free distances. The authors. first propose a novel analysis technique for the performance of coded modulation on limited diversity block fading channels with different modulation sets on each block. The authors then propose adaptive modulation techniques for maximising the throughput at a. fixed bit error probability and also for minimising the bit error probability at a. fixed rate. Lastly, the authors show simulation results that support the arguments presented in the paper.

关键词： transmitters modulation coding fading channels indoor orthogonal frequency division multiplexing systems modulation and coding methods coded modulation fixed bit error probability Radio links and equipment channel state information diversity reception limited diversity fading channels error statistics adaptive modulation transmitter Other topics in statistics

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Low-complexity LDPC coded BICM-ID with orthogonal modulations

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ELECTRONICS LETTERS 2009年第16期45卷 845-U57页

作者： Che, S. Tong, S. Xidian Univ State Key Lab ISN Xian Peoples R China City Univ Hong Kong Dept Elect Engn Hong Kong Hong Kong Peoples R China

A low-complexity low density parity check (LDPC) coded bit-interleaved coded modulation with iterative decoding (BICM-ID) scheme with orthogonal modulations is proposed. With a novel mapping strategy of coded bits to symbols, the proposed scheme is equivalent to a generalised LDPC code with Hadamard constraints and thus orthogonal demodulation can be merged into the iterative LDPC decoding process, resulting in a simpler implementation and a lower computational complexity.

关键词： Orthogonal complexity classes Equivalent modulation coding low density parity check codes Bit interleaved coded modulation

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Turbo-Like Structures for Chaos Encoding and Decoding

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IEEE TRANSACTIONS ON COMMUNICATIONS 2009年第3期57卷 597-601页

作者： Escribano, Francisco J. Kozic, Slobodan Lopez, Luis Sanjuan, Miguel A. F. Hasler, Martin Univ Alcala de Henares Dept Signal Theory & Commun Alcala De Henares 28805 Spain Ecole Polytech Fed Lausanne Sch Comp & Commun Sci I&C CH-1015 Lausanne Switzerland Univ Rey Juan Carlos Dept Sistemas Telemat & Computac Mostoles 28933 Spain Univ Rey Juan Carlos Dept Fis Mostoles 28933 Spain

In this paper, we explain how to build a turbo-like structure with binary inputs and chaotic outputs for efficient coding and decoding in additive white Gaussian noise (AWGN). We analyze the convergence of the decoding algorithm, the performance in the error floor region and explain minimum distance properties of the resulting codes.

关键词： Channel coding chaos concatenated coding modulation coding error analysis

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VEP-Based Brain-Computer Interfaces: Time, Frequency, and Code modulations

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IEEE COMPUTATIONAL INTELLIGENCE MAGAZINE 2009年第4期4卷 22-26页

作者： Bin, Guangyu Gao, Xiaorong Wang, Yijun Hong, Bo Gao, Shangkai Tsinghua Univ Beijing 100084 Peoples R China

A brain computer interface (BCI) translates human intentions into control signals to establish a direct communication channel between the human brain and external devices. Because a BCI does not depend on the brain's normal output pathways of peripheral nerves and muscles, it can provide a new communication channel to people with severe motor disabilities.

关键词： Brain computer interfaces Frequency modulation modulation coding Humans Communication channels Electroencephalography Communication system control Muscles Scalp System performance

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The Power Spectrum Computation and Spectrum Performance Evaluation of a New Optical modulation Code

The Power Spectrum Computation and Spectrum Performance Eval...

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8th International Symposium on Optical Storage and 2008 International Workshop on Information Data Storage

作者： Ye Zhen Hu Diqing HuaZhong Univ Sci & Technol Coll CS Wuhan Natl Lab Optoelect Wuhan 430074 Peoples R China

ISBN: (纸本)9780819473592

The traditional method of power spectrum computation of modulation code is that firstly computing the autocorrelation function of the code, and then taking Fourier transform of the autocorrelation function to get the power spectrum. Unfortunately, it is difficult to get autocorrelation function according to the coding methods, therefore, the traditional method is not fit to compute power spectrum of practical RLL code. In this article, we use a method that is based on one-step state-transition matrix is much simpler, which all the parameters can be computed according to RLL coding methods. We use the method to compute the power spectrum of a new modulation code called RLL (2, 12;8, 15), and evaluate the spectrum performance of the new modulation code according to the power spectrum. Meanwhile, we improve the new modulation code in order to get a better spectrum performance.

关键词： Optical storage modulation coding run-length limited code power spectrum

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Resource Allocation for Adjustable QoS in OFDMA Wireless Networks

Resource Allocation for Adjustable QoS in OFDMA Wireless Net...

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International Conference on Information Networking

作者： Ruangchaijatupon, Nararat Ji, Yusheng Grad Univ Adv Studies Chiyoda Ku Tokyo Japan

ISBN: (纸本)9781424445264

We propose a centralized resource allocation scheme called Proportional Fairness with Adjustable QoS (PF-AQ) for an OFDMA wireless system, which transmitting data on a frame basis. We have network resources in frequency and time domains. We develop a simple and efficient user selection, subchannel assignment, and time slot allocation based on PF utility function with a consideration of realistic queue length. Our scheme schedules a batch of packets which can extend across multiple time slots at a time, and employs multi-user diversity to maximize system throughput while keeping throughput fairness. Our scheme enhances fairness by the limitation of the maximum number of time slots assigned to each user per frame. QoS in terms of throughput and queue size can also be adjusted by adjusting this limitation.

关键词： Resource management Wireless networks Throughput modulation coding Interference Informatics Frequency conversion WiMAX Narrowband Bandwidth

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Development of Digital Experiment System for Multi-module-cascaded Multilevel High-power Inverter

Development of Digital Experiment System for Multi-module-ca...

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6th IEEE International Power Electronics and Motion Control Conference

作者： Zhou Jinghua Chen Yaai Yao Lanya Li Zhengxi N China Univ Technol Power Elect & Motor Driver Engn Ctr Beijing 100144 Peoples R China

ISBN: (纸本)9781424435562

Based on a multi-module-cascaded multilevel inverter structure for the optimization of harmonics, this paper introduces a horizontal phase-shifting sinusoidal pulse width modulation (SPWM) strategy applied to multi-module-cascaded inverter, and at the same time, based on Digital Signal Processor (DSP) and Complex Programmable Logic Device (CPLD), this paper also presents a digital algorithm for horizontal phase-shifting SPWM modulation, which has solved the problem of the exactly lock of each triangular carrier phase in the multi-module-cascaded system. The simulation and experimental results have proven the method proposed correct.

关键词： Pulse width modulation inverters Digital signal processing Voltage Pulse inverters Phase modulation Digital modulation modulation coding Digital control Frequency Power electronics

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