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5th International Conference on Signal and Image Processing (ICSIP)

作者： Khanai, Rajashri Kulkarni, G. H. Torse, Dattaprasad A. Gogte Inst Technol Dept Elect & Elect Engn Belgaum Karnataka India Jain Coll Engn Dept Elect & Elect Engn Belgaum Karnataka India Visvesvaraya Technol Univ Belgaum Karnataka India

ISBN: (纸本)9780769551005

In this paper, we have introduced an improved combined cryptography-error correction method, which is called "Crypto-coding". Although in previous experiments, combined error correction and encryption functionality has been studied into one single step, the modification needed in the introduction of encryption block improves the performance of the system. The combined System's performances are evaluated on Land Mobile Satellite (LMS) Channel. The results are compared with the system using ideal encryption and decryption.

关键词： Crypto-coding convolutional coding Simplified Data Encryption Standard Land Mobile Satellite (LMS) Channel

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Performance Improvement of WiMAX (IEEE 802.16d) Using Combined RS-CC Forward Error Channel coding Technique 1

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1st International Conference on Advanced Computational and Communication Paradigms (ICACCP)

作者： Agarwal, Arun Mehta, Saurabh N. AMET Univ Dept Informat Technol Madras 603112 Tamil Nadu India Siksha OAnusandhan Deemed Univ ITER Dept EIE Khandagiri Sq Bhubaneswar 751030 Odisha India Vidyalankar Inst Technol Dept Elect & Telecommun Engn Bombay 400037 Maharashtra India

ISBN: (数字)9789811082405

ISBN: (纸本)9789811082405;9789811082399

Higher data rates at lower power levels, Internet, and wireless multimedia applications are the demands of future wireless digital communication links than most of today’s systems. Today’s available wireless network technologies due to certain limitations fail to fulfill customer requirements. This motivation directed researchers to develop more advanced and efficient technology. Orthogonal Frequency Division Multiplexing (OFDM)-based WiMAX (Worldwide Interoperability for Microwave Access) system is one of them. WiMAX is the latest last mile wireless technologies to deliver broadband access services to residential and enterprise customers in an economical way. This system is incorporated with powerful channel coding along with interleaving to achieve time diversity. This work presents design and analysis of the Bit Error Rate (BER) performance of the WiMAX baseband physical layer as per the parameters set by IEEE 802.16 standards under concatenated channel coding techniques, whereby a Reed–Solomon (RS) code is added with convolutional coding (CC). BER analysis confirmed that RS–CC channel coding gives better noise performance of the system with minimal SNR.

关键词： BER Concatenated coding convolutional coding High-speed Internet OFDM Reed–Solomon code WiMAX

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Design of a ZigBee Based WSN with Channel coding for Energy and Temperature Monitoring

Design of a ZigBee Based WSN with Channel Coding for Energy ...

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Al-Sadiq International Conference on Multidisciplinary in IT and Communication Techniques Science and Applications (AIC-MITCSA)

作者： Abdullah, Hikmat N. Salman, Tariq M. Alobaidy, Haider A. H. Univ Al Nahrain Coll Informat Engn Baghdad Iraq Al Mustansiriya Univ Coll Engn Dept Elect Engn Baghdad Iraq

ISBN: (纸本)9781509032471

This paper has two objectives. First, to design and implement a prototype of WSN for monitoring power as well as temperature in buildings. Second, to evaluate the amount of improvement introduced to the ZigBee transceiver when channel-coding method is used. The results indicated that the use of ZigBee based WSN in electric power monitoring provides flexibility and helps in reducing power consumption. Furthermore, the simulation results show that using convolutional coding (CC) in ZigBee transceiver gives better performance compared to traditional ZigBee transceivers specially at CC of code rate 1/8.

关键词： Wireless Sensor Network (WSN) ZigBee IEEE 802.15.4 convolutional coding Automation Monitoring

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Performance of multi-relay coded cooperative diversity in asynchronous code-division multiple-access over fading channels

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IET COMMUNICATIONS 2011年第5期5卷 683-692页

作者： Eid, A. Hamouda, W. Dayoub, I. Concordia Univ Dept Elect & Comp Engn Montreal PQ H3G 1M8 Canada Univ Valenciennes IEMN DOAE F-59313 Le Mt Houy Valenciennes France

In this study, multi-relay decode-and forward (DAF) cooperative networks employing convolutional coding are studied for asynchronous direct-sequence code-division multiple-access (DS-CDMA) systems over frequency-selective slow fading channels. The authors show that the full benefits of coded cooperative diversity cannot be achieved if no multi-user interference suppression is employed at the cooperative end. The authors consider two scenarios;perfect and imperfect inter-user channels. In that, the bit-error-rate performance of the cooperative system is investigated for an uplink transmission where a decorrelator detector is used at both the relay and base station receivers. Both simulation and analytical results are presented to demonstrate the diversity gains of the convolutionally coded cooperative network.

关键词： Direct-sequence code-division multiple access relay Code division multiple access convolutional coding Asynchronous Fading channels

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HAMMING DISTANCE PRESERVING MAPPINGS AND TRELLIS CODES WITH CONSTRAINED BINARY SYMBOLS

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IEEE TRANSACTIONS ON INFORMATION THEORY 1989年第5期35卷 1098-1103页

作者： FERREIRA, HC WRIGHT, DA NEL, AL SAN DIEGO STATE UNIV DEPT ORNAMENTAL HORT SAN DIEGO CA 92182 USA

The transformation of a linear convolutional code into a run-length-constrained or balanced trellis code with the same or larger free distance is investigated. The transformation involves a Hamming-distance-preserving mapping of the set of unconstrained binary symbols of the convolutional code onto a set of suitably constrained symbols. Simple tests to determine if these mappings can exist and a tree search algorithm for finding such mappings are presented.

关键词： Signs and symbols Binary Trellis codes convolutional coding SEARCHING ALGORITHM Hamming distance

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PHY and MAC performance evaluation of IEEE 802.11a WLAN over fading channels

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IETE JOURNAL OF RESEARCH 2005年第1期51卷 83-94页

作者： Yomo, H Nguyen, CH Kyritsi, P Nguyen, TD Prasad, R Aalborg Univ Ctr TelenFrastruct DK-9920 Aalborg Denmark Acad Finland FIN-02015 Helsinki Finland Aalto Univ FIN-02015 Helsinki Finland

This paper presents an overview of physical (PHY) and medium access control (MAC) layers for IEEE 802.11a, which is a standard of a broadband high-speed wireless local area network (WLAN). IEEE 802.11a uses 5 GHz frequency band and its PHY is based on orthogonal frequency division multiplexing (OFDM). In this paper, we evaluate the OFDM-based PHY and MAC performance of IEEE 802.11a under various practical wideband channel models, which are abstracted from actual propagation measurements. The effects of different transmission modes defined in PHY on the IEEE 802.11 system performance are investigated. We also discuss the impact of link adaptation, which attempts to choose the best-suited transmission mode according to channel conditions, on the overall system performance.

关键词： OFDM IEEE 802.11a HYPERLAN/2 IFFT convolutional coding time dispersive frequency selective wideband rayleigh fading MAC link adaptation

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Switchable-rate quasi-cyclic low-density parity-check codes for internet protocol over high-frequency systems

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IET COMMUNICATIONS 2011年第4期5卷 505-511页

作者： Heravi, B. M. Kariyawasam, S. R. Vongas, G. Honary, B. Univ Lancaster Dept Commun Syst Lancaster LA1 4WA England Def Sci & Technol Lab Fareham PO17 6AD Hants England

A switchable-rate quasi-cyclic low-density parity-check (QC-LDPC) coding scheme has been proposed for integration within the legacy and next-generation high-frequency internet protocol (HF-IP) systems. The novelty in this work is based upon using a class of switchable-rate short-block-length (<1500 bits) QC-LDPC codes for the HF fading channel modelled by the ITU-R F. 1487 for all latitudes and conditions. The QC-LDPC codes are constructed using a switchable-rate approach based on finite fields which provides the ability to switch among three rates to combat varying channel conditions using a single encoder/decoder structure. The proposed structure enables low-complexity implementation of the low-density parity-check encoder/decoder for use within the existing data link (DL) layer of the standardisation agreement (STANAG) 5066 profile. The performance of the proposed scheme has been evaluated comprehensively for all the HF channel conditions and latitudes. A comparison between the proposed and the current coding scheme in HF-IP systems (based on convolutional coding) shows an improvement in error-rate performance.

关键词： encoder structure ITU-R F.1487 parity check codes Protocols switchable-rate quasi-cyclic low-density parity-check codes convolutional codes Codes fading channels encoding cyclic codes IP networks Computer communications decoding high-frequency Internet protocol system finite field high-frequency fading channel Other computer networks decoder structure Internet protocols standardisation agreement 5066 profile Radio links and equipment convolutional coding

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Performance-complexity tradeoff of convolutional codes for broadband fixed wireless access systems

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IET COMMUNICATIONS 2010年第4期4卷 419-427页

作者： Chatzigeorgiou, I. Demosthenous, A. Rodrigues, M. R. D. Wassell, I. J. Univ Cambridge Comp Lab Digital Technol Grp Cambridge CB3 0FD England UCL Dept Elect & Elect Engn London WC1E 7JE England Univ Porto Dept Comp Sci P-4169007 Oporto Portugal Univ Porto Inst Telecomunicacoes P-4169007 Oporto Portugal

In this study, the authors investigate the performance-complexity tradeoff of convolutional codes for broadband fixed wireless access systems by considering the effects of quantisation and path metric memory in practical Viterbi decoding implementations. They show that in systems with limited antenna diversity, low-memory codes achieve a better error-rate performance compared to that of high-memory codes. Only in systems with considerable antenna diversity, can the performance of a convolutional code be improved by increasing its memory size. Nevertheless, the authors demonstrate that the coding advantage offered by the high-memory codes is not large enough to justify the significant increase in implementation complexity. In particular, memory-2 convolutional codes achieve a coding gain of up to 1.2 dB over their memory-8 counterparts in single-input single-output fixed wireless access systems. The situation is reversed when multiple antennas are used, but the decoder of memory-8 codes occupies at least 130 times more silicon area than that of memory-2 codes.

关键词： tradeoffs Quantization broadband spatial diversity multiple antenna convolutional coding Codes coding gain wireless diversity reception

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THE PERFORMANCE OF RATE-COMPATIBLE PUNCTURED convolutional-CODES FOR DIGITAL MOBILE RADIO

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IEEE TRANSACTIONS ON COMMUNICATIONS 1990年第7期38卷 966-980页

作者： HAGENAUER, J SESHADRI, N SUNDBERG, CEW AT&T BELL LABS MURRAY HILLNJ 07974

The unequal error protection capabilities of convolutional codes belonging to the family of rate-compatible punctured convolutional codes (RCPC codes) are studied. The performance of these codes is analyzed and simulated for the first fading Rice and Rayleigh channels with differentially coherent four-phase modulation (4-DPSK). To mitigate the effect of fading, interleavers are designed for these unequal error protection codes, with the interleaving performed over one or two blocks of 256 channel bits. These codes are decoded by means of the Viterbi algorithm using both soft symbol decisions and channel state information. For reference, the performance of these codes on a Gaussian channel with coherent binary phase-shift keying (2-CPSK) is presented. A number of examples are provided to show that it is possible to accommodate widely different error protection levels within short information blocks. Unequal error protection codes for a subband speech coder are studied in detail. A detailed study of the effect of the code and channel parameters such as the encoder memory, the code rate, interleaver depth, fading bandwidth, and the contrasting performance of hard and soft decisions on the received symbols is provided.

关键词： fading color error protection inequalities Codes Viterbi algorithm protection level Gaussian channels Channel state information convolutional coding soft decision

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Metric-based node synchronization of the Viterbi decoder in satellite applications

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INTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS 2000年第1期18卷 1-15页

作者： Fair, IJ Brown, JM Univ Alberta Dept Elect & Comp Engn Edmonton AB T6G 2G7 Canada Nokia IP Telephony Kanata ON K2K 2X3 Canada

convolutional codes are used in digital communication systems to correct errors that occur during transmission. Their use is now commonplace, particularly in power-limited satellite and deep space communication systems. Before the decoder can correctly decode the received continuous bit sequence, however, it must establish where codewords begin and end in this sequence, The process of determining codeword boundaries is called node synchronization. In this paper we develop a node synchronization algorithm based on metric difference values with the objectives of simple implementation and reliable performance. Focusing on satellite applications, we consider the constraint length 7, rate 1/2 convolutional code standardized by the National Aeronautics and Space Administration (NASA) and the European Space Agency (ESA);the approach we develop can be extended to other convolutional coding systems. Through simulation, we investigate the statistics of the received sequence, and highlight correlation in the sequence of the decoder metric values. In the light of these observations, we propose a synchronization algorithm, and develop a first-order analysis of this simple up/down counter framing technique. We recommend framing parameters based on both the analytical results and the expected response of the framing algorithm to correlated metric values. Development of a simple node synchronization algorithm that accommodates correlated metric values has not been reported previously in the literature. Simulation results confirm that reliable node synchronization is possible with this very simple approach. Copyright (C) 2000 John Wiley & Sons, Ltd.

关键词： convolutional coding Viterbi decoding node synchronization self-framing

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