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IEEE Visual Communications and Image Processing (VCIP)

作者： Taieb, Mohamed Haj Chouinard, Jean-Yves Wang, Demin Univ Laval Quebec City PQ G1V 0A8 Canada Commun Res Ctr Canada Ottawa ON K2H 8S2 Canada

ISBN: (纸本)9781467344050;9781467344067

Distributed video coding paradigm aims at transferring the major part of the processing computation effort from the encoder to the decoder. Motion interpolation is done at the decoder to generate side information (SI) through motion compensated temporal interpolation (MCTI). SI is considered as a noisy version of the original data: channel control coding schemes, such as turbo coding, are used to eliminate the errors (SI inaccuracies). The video data is turbo encoded and the parity bits are sent to the decoder. The systematic bits, however, are discarded since the decoder already disposes of SI that can be used for the channel likelihood ratio calculations. However, when the MCTI generation of SI is highly corrupted, the channel likelihood ratios based on the SI are inefficient and even misleading. A number of parity bits number exceeding the original data length may then be required, thus leading to an undesirable expansion effect. In this paper, we propose a method to detect adaptively the situations where the SI is of lower quality. Then puncturing matrices, enabling systematic bits, are used to help computing reliable channel likelihood ratios. An improvement up to 0.5 dB is reported for PSNRs vs bit rate performances.

关键词： Distributed video coding turbo coding motion interpolation puncturing

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coding for Increase of Data Transmission Robustness Via Orthogonal Parallel Sub-Channels 13

Coding for Increase of Data Transmission Robustness Via Orth...

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13th International Conference on Modern Problems of Radio Engineering, Telecommunications and Computer Science (TCSET)

作者： Shestopal, Yevgenii State Univ Telecommun Solomyanska Str 7 Kiev Ukraine

In this paper the overview of turbo coding technique applying to orthogonal parallel data transmission via sub-channels is provided and soft-input soft-output maximum a posteriori algorithm is proposed for using in pa... 详细信息

ISBN: (纸本)9786176078067

关键词： OFDM turbo codes turbo coding convolutional codes parallel data transmission

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Distributed video coding in pixel domain using spatial correlation at the decoder

Distributed video coding in pixel domain using spatial corre...

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Data Compression Conference (DCC)

作者： Lahsini, Cyrine Zaibi, Sonia Pyndiah, Ramesh Bouallegue, Ammar Telecom Bretagne Signal & Commun Dept Brest France ENIT Syscom Lab Tunis Tunisia

ISBN: (纸本)9780769543529

Distributed coding is a new paradigm for video compression based on Slepian-Wolf (1973) and Wyner-Ziv (1976) theorems. In this paper, we propose a new pixel-domain Distributed Video coding (DVC) scheme, in which both the temporal and the spatial correlations are exploited only at the decoder. A joint source-channel decoding is implemented to exploit the source statistics. Iterations between the Map channel decoder and the BCJR source decoder are made to improve the global decoder performance. Simulations results show that a gain is obtained, in term of rate, with iterative joint source-channel decoding, compared to the basic decoding.

关键词： distributed video coding joint source-channel decoding turbo coding Video coding decoders Video compression Channel Decoder turbo codes DEcoding Combined source-channel coding

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BER Analysis of Mobile WiMAX System using LDPC coding and MIMO System under Rayleigh Channel

BER Analysis of Mobile WiMAX System using LDPC Coding and MI...

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2nd IEEE International Conference on Communications and Signal Processing (ICCSP)

作者： Sahoo, Biswajit Prasad, Ravi Ranjan Samundiswary, P. Pondicherry Univ Dept Elect Engn Pondicherry India

ISBN: (纸本)9781467348669;9781467348652

With the integration of internet and multimedia applications in next generation wireless communication, the demand for wide-band high data rate communication services is increasing. Since the available spectrum is limited and user demand continues to grow, this problem could be solved by WiMAX (Worldwide Interoperability for Microwave Access) technology. WiMAX supports high data rate and high capacity in mobile BWA (Broadband Wireless Access). The performance of WiMAX system can be enhanced by incorporating better channel coding technique in the system. It can be further improved by incorporating MIMO (Multiple-Inputs Multiple-Outputs) technique. The introduction of MIMO with STC (Space Time Code) provides a robust platform for space, time and frequency selective fading conditions and increases both data rate and system performance. In this paper, the performance of mobile WiMAX system using LDPC (Low Density Parity Check) coding and MIMO system considering STC techniques under Rayleigh channel is simulated and analyzed.

关键词： Low Density Parity Check Code Multiple Input Multiple Output STBC Space Time Trellis Code turbo coding WiMAX

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Analysis of Modulation and coding Scheme for 5th Generation Wireless Communication System

Analysis of Modulation and Coding Scheme for 5th Generation ...

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IEEE International Conference on Computing, Communication and Automation (ICCCA)

作者： Al Amin, Ahmed Basak, Devashish Khadem, Tania Hossen, Md. Delwar Islam, Md. Shoriful Uttara Univ Dept Elect & Elect Engn Dhaka Bangladesh Khulna Univ Engn & Technol Dept EEE Khulna Bangladesh Chittagong Univ Engn & Technol Dept Elect & Elect Engn Chittagong Bangladesh

ISBN: (纸本)9781509016662

Advancing in communication technology, 5th Generation Wireless Communication System is playing a significant role. The 5th Generation wireless communication system involves different types of coding and modulation schemes for the better performances and efficient outputs. This paper analyzes the different coding schemes and modulation techniques and compares between them. The performances have been compared between the turbo and Viterbi coding Schemes. And the modulation techniques have been compared between QPSK and QAM modulation techniques. The QAM modulation scheme will be used for the users closer to the BTS (Base Transceiver Station). And QPSK modulation technique will be used for the users closer to the border of the cells. For both of the modulation techniques, both the coding schemes have been used and performances have been compared. Finally for all the modulation schemes, Viterbi coding techniques (Convolutional Encoding and Viterbi Decoding) have proved its efficient performances in use.

关键词： QAM QPSK LTE turbo coding Viterbi coding Convolutional encoding

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From Source coding to MIMO - A Multi-Level Unequal Error Protection

From Source Coding to MIMO - A Multi-Level Unequal Error Pro...

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IEEE Region 10 Conference (TENCON)

作者： Barmada, Bashar Rehman, Saeed Unitec Inst Technol Dept Comp Sci Auckland New Zealand

ISBN: (纸本)9781509025978

In this paper, unequal error protection (UEP) on different levels of the transmission system is proposed. Starting from the source coding level, two priority layers are produced, high priority (HP) and low priority (LP). At channel coding, each priority layer is turbo encoded with a coding rate that reflects its importance. For modulation, a more immune modulation mode is used to modulate the HP bit stream. Finally at the transmission level, a 3 x 3 MIMO is used, where more transmit antennas and time slots are offered to HP data. This arrangement of inequality over several levels increases the flexibility of the UEP system and leads to a better performance. Results show that the proposed system outperforms other semi-unequal and equal error protection systems over a wide range of channel signal-to-noise ratio (SNR), especially at low SNR values.

关键词： Unequal error protection Multi-layer source coding turbo coding MIMO with spatial-time code

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Limits of error correction coding in video watermarking

Limits of error correction coding in video watermarking

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5th Conference on Security and Watermarking of Multimedia Contents

作者： Ambroze, M Tomlinson, M Serdean, C Wade, G Univ Plymouth Dept Commun & Elect Engn Plymouth PL4 8AA Devon England

ISBN: (纸本)0819448206

The paper discusses the limits of error correction coding for spread spectrum-based video watermarking. The error correction code has as input the watermark data bits and as output the values which will be scaled and used to modify the video pixels (transform coefficients). The data rate of the watermark can increase only at the expense of increasing code rate. Theoretically, the scheme is seen as a communication channel with Gaussian additive noise interference. Shannon's (ideal) spherical codes are used as the error correcting code to calculate the minimum signal to noise ratio (SNR) necessary for a coding scheme with a given block length to achieve a given error probability. This limit is different from Shannon's asymptotic limit, which is valid for infinite block lengths and zero error probability. In practice, in order to verify the Gaussian channel assumption, the error correction code is a concatenation of codes, of which the innermost is a repetition code. Several practical codes of different length and rates, such as turbo codes and BCH codes are investigated and their performance compared to that of the ideal code of the same size. The compromise block length/code rate is investigated for several marking schemes and attacks.

关键词： video watermarking turbo coding Shannon limit

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Spread Spectrum Techniques with Channel coding for Wideband Secured Communication Links

Spread Spectrum Techniques with Channel Coding for Wideband ...

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IEEE International Symposium on Antennas and Propagation (IEEE AP-S) / IEEE USNC-CNC-URSI Radio Science Meeting

作者： Rahman, Md Rakibur Bojja-Venkatakrishnan, Satheesh Alwan, Elias A. Volakis, John L. Florida Int Univ Dept Elect & Comp Engn Miami FL 33199 USA

ISBN: (纸本)9781728166704

Ultra-wideband (UWB) radios provide avenues for interference immunity using spread spectrum (SS) techniques. Doing so, provides a processing gain of 21 dB, allowing for successful retrieval of signals propagated below the noise floor. In addition, by applying advanced channel coding an additional coding gain of 9 dB can be achieved. In this paper, we are exploiting SS techniques with channel coding to maximize gain in wireless communication links. Bit error rate (BER) performance is presented for multiple channel coding approaches.

关键词： Ultra wideband spread spectrum interference mitigation secure wireless communication polar coding LDPC turbo coding

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Implementation and performance of a turbo/MAP decoder

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INTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS 1998年第1期16卷 23-46页

作者： Pietrobon, SS Small World Commun Payneham S SA 5070 Australia

The implementation and performance of a turbo/MAP decoder are described. A serial block MAP decoder operating in the logarithm domain is used to obtain a very-high-performance turbo decoder. Programmable gate arrays and EPROMs allow the decoder to be programmed for almost any code from four to 512 states, rate 1/3 to rate 1/7 (higher rates are achieved with puncturing) and interleaver block sizes to 65,536 bits. Seven decoding stages were implemented in parallel. For rate 1/3 and 1/7 16-state codes with an interleaver size of 65,536 bits and operating at up to 356 kbit/s the codec achieved an E-b/N-0 of 0.32 and -0.30 dB respectively for a BER of 10(-5). BERs down to 10(-7) were also achieved for a small increase in Eb/N0. An efficient implementation of a continuous MAP decoder is also presented, along with a synchronization technique for turbo decoders. (C) 1998 John Wiley & Sons, Ltd.

关键词： turbo coding MAP decoding synchronization

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An improved sliding window algorithm for Max-Log-MAP turbo decoder and its programmable LSI implementation

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IEICE TRANSACTIONS ON ELECTRONICS 2005年第3期E88C卷 403-412页

作者： Gambe, H Tanaka, Y Ohbuchi, K Ishihara, T Li, JF Fujitsu Labs Ltd Kawasaki Kanagawa 2118588 Japan

Thanks to the possibility of being able to implement them in decoders in relatively simple ways, turbo codes are being applied to various areas of engineering. Wireless communications is one of the most important applications, where various types of data communications are required and the speed of information and data capacity need to be changed with different rates of parity bit puncturing being adopted to obtain highly efficient transmission. In such applications, adaptation to various turbo-coding specifications on a real-time basis is needed as well as good bit-error-rate performance. We present a new concept for simplifying metric computation and programmable circuit configurations that focuses on the convolutional decoder, which occupies a significant portion of allocated hardware, and we fundamentally treat a simplified log-domain version of the maximum a posteriori (MAP) algorithm, usually know as the Max-Log-MAP (MLM), as a base algorithm. The sliding window method provides an attractive way of computing metric values for the Max-Log-MAP. However, this algorithm does cause degradation, especially when a high rate code is used, generated by bit puncturing. We propose a new means of avoiding this problem and demonstrate that the sliding window, and a modified version as well as other methods, should be flexibly selected to utilize hardware resources depending on turbo specifications. We demonstrated that our proposed methods provide almost the same BER performance as MLM even when a high rate puncturing rate of 5/6 is applied. Finally, we describe the new hardware architecture that we invented to cope with these programmability issues. We show that a turbo-decoding circuit can be implemented in the processor core and its associated unit to configure an LSI macro circuit. The proposed unit has about 60-K gates. We demonstrate that this architecture can be applied to about the 1.5-Mbps information bit throughput of turbo decoding with a 200-MHz clock cycle, wh

关键词： turbo coding MAP algorithm Max-Log-MAP sliding window

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