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Compression of binary memoryless sources using punctured turbo codes

IEEE COMMUNICATIONS LETTERS 2002年第9期6卷 394-396页

作者： Garcia-Frias, J Zhao, Y Univ Delaware Dept Elect & Comp Engn Newark DE 19716 USA

In this letter, we propose the use of punctured turbo codes to perform near-lossless compression and joint source-channel coding of binary memoryless sources. Compression is achieved by puncturing the turbo code to the desired rate. No information about the source distribution is required in the encoding process. Moreover, the source parameters do not need to be known in the decoder, since they can be estimated jointly with the iterative decoding process.

关键词： data compression joint source-channel coding punctured turbo codes source coding

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Near-Shannon/Slepian-wolf performance for unknown correlated sources over AWGN channels

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IEEE TRANSACTIONS ON COMMUNICATIONS 2005年第4期53卷 555-559页

作者： Garcia-Frias, J Zhao, Y Univ Delaware Dept Elect & Comp Engn Newark DE 19716 USA

We consider the problem of joint source-channel coding of two correlated binary information sequences. Instead of compressing the information using source coding, both sequences are independently channel encoded and transmitted over two independent additive white Gaussian noise channels. No information about the correlation between the sources is required in the encoding process. The correlation between both sequences is exploited at the receiver, allowing reliable communications at signal-to-noise ratios very close to the theoretical limits established by the combination of Shannon and Slepian-Wolf theorems. This occurs even when the correlation between sources is not known at the decoder, since it can be estimated jointly with the iterative decoding process.

关键词： additive white Gaussian noise (AWGN) channels correlated sources iterative decoding joint source-channel coding turbo codes

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An Improved Encoder for joint source-channel Decoder Using Conditional Entropy Constraint

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IEICE TRANSACTIONS ON COMMUNICATIONS 2009年第6期E92B卷 2222-2225页

作者： Park, Moonseo Kim, Seong-Lyun Yonsei Univ Ind Acad Cooperat Fdn Seoul 120749 South Korea Yonsei Univ Sch Elect & Elect Engn Radio Res Management & Optimizat Lab Seoul 120749 South Korea Ajou Univ Div Elect & Comp Engn Commun Syst Lab Suwon 443749 South Korea

When the joint source-channel (JSC) decoder is used for source coding over noisy channels, the JSC decoder may invent errors even though the received data is not corrupted by the channel noise, if the JSC decoder assumes the channel was noisy. A novel encoder algorithm has been recently proposed to improve the performance of the communications system under this situation. In this letter, we propose another algorithm based on conditional entropy-constrained vector quantizer to further improve the encoder. The algorithm proposed in this letter significantly improves the performance of the communications system when the hypothesized channel bit error rate is high.

关键词： conditional entropy-constrained vector quantizer hidden Markov model joint source-channel coding

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Variable-length error-correcting codes

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IEE PROCEEDINGS-COMMUNICATIONS 2000年第4期147卷 211-215页

作者： Buttigieg, V Farrell, PG Univ Malta Dept Commun & Comp Engn Msida Malta Univ Lancaster Fac Sci Appl Commun Res Ctr Lancaster LA1 4YR England

Variable-length error-correcting codes, suitable to perform joint source-channel coding, are presented. A maximum likelihood decoding algorithm for these codes is given. Some performance bounds are derived and it is shown that these codes are similar to convolutional codes. The free distance of these codes is defined and it is shown that it is the most important parameter that determines their performance at high E-b/N-o. It is shown that the performance of these codes can be better than a standard cascade of a Huffman code followed by a BCH code with the same code parameters.

关键词： Viterbi decoding variable length codes maximum likelihood decoding joint source-channel coding performance bounds free distance Codes variable-length error-correcting codes error correction codes combined source-channel coding maximum likelihood decoding algorithm modified Viterbi decoding

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Turbo codes for nonuniform memoryless sources over noisy channels

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IEEE COMMUNICATIONS LETTERS 2002年第2期6卷 64-66页

作者： Zhu, GC Alajaji, F Queens Univ Dept Math & Stat Kingston ON K7L 3N6 Canada Queens Univ Dept Elect & Comp Engn Kingston ON K7L 3N6 Canada

This work addresses the problem of designing Turbo codes for nonuniform binary memoryless or independent and identically distributed (i.i.d.) sources over noisy channels. The extrinsic information in the decoder is modified to exploit the source redundancy in the form of nonuniformity;furthermore, the constituent encoder structure is optimized for the considered nonuniform i.i.d. source to further enhance the system performance. Some constituent encoders are found to substantially outperform Berrou's (37, 21) encoder. Indeed, it is shown that the bit error rate (BER) performance of the newly designed Turbo codes is greatly improved as significant coding gains are obtained.

关键词： AWGN and Rayleigh channels joint source-channel coding nonuniform i.i.d. sources turbo codes

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A UEP Method for Imaging Low-Orbit Satellites Based on CCSDS Recommendations

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IEEE GEOSCIENCE AND REMOTE SENSING LETTERS 2018年第11期15卷 1770-1774页

作者： Schwartz, Christofer Torezzan, Cristiano Duarte, Leonardo Tomazeli Univ Estadual Campinas Sch Appl Sci BR-13083970 Limeira SP Brazil

Remote sensing satellites allow continuous information acquisition from large areas of the earth and have been intensively applied in a number of applications, from agriculture to defense. A major challenge in remote sensing is that satellite communication systems present bandwidth restrictions and several issues typical of time-variant channels, which justifies the need for signal coding techniques. In that sense, this letter proposes an unequal error protection method for aerospace applications using the recommendations for source and channel coding created by the Consultative Committee for Space Data System (CCSDS) as frameworks. The proposed method makes use of the CCSDS-recommended convolutional code to ensure a channel coding step as low complex as possible, which allows implementation in a wide range of embedded platforms. This letter exploits the natural data division delivered by the compressor to unequally protect the information. The proposed method, which relies on a multiobjective optimization problem, allows one to find rate arrangements that minimize the distortion of the received image for a given value of an average coding rate within a granular range. The system performance is evaluated over an additive white Gaussian noise channel model. The obtained results show that the proposed method presents several advantages over an equal error protection strategy, and paves the way for scenarios with stringent energy and bandwidth constraints.

关键词： Image coding joint source-channel coding satellite communication unequal error protection (UEP)

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On the distortion SNR exponent of some layered transmission schemes

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IEEE TRANSACTIONS ON INFORMATION THEORY 2008年第7期54卷 2943-2958页

作者： Bhattad, Kapil Narayanan, Krishna R. Caire, Giuseppe Qualcomm Inc San Diego CA 92121 USA Texas A&M Univ Dept Elect & Comp Engn College Stn TX 77843 USA Univ So Calif Dept Elect Engn Viterbi Sch Engn Los Angeles CA 90089 USA

We consider the problem of joint source-channel coding for transmitting K samples of a complex Gaussian source over T = bK uses of a block-fading multiple-input multiple-output (MIMO) channel with M transmit and N receive antennas. We consider the case when we are allowed to code over L blocks. The channel gain is assumed to be constant over a block and channel gains for different blocks are assumed to be independent. The performance measure of interest is the rate of decay of the expected mean-squared error with the signal-to-noise ratio (SNR), called the distortion SNR exponent. We first show that using a broadcast strategy similar to that of Gunduz and Erkip, but with a different power and rate allocation policy, the optimal distortion SNR exponent can be achieved for 0 <= b < (vertical bar N - M vertical bar + 1) / min (M, N) and for b > MNL2. This is the first time the optimal exponent is characterized for 1/ min(M, N) < b < (vertical bar N - M vertical bar + 1)/ min(M, N). Then, we propose a digital layered transmission scheme that uses both time layering and superposition. The new scheme is at least as good as currently known schemes for the entire range of bandwidth expansion factors b, whereas at least for some M, N, and b, it is strictly better than the currently known schemes.

关键词： broadcast distortion signal-to-noise ratio (SNR) exponent diversity-multiplexing tradeoff joint source-channel coding layered source-channel coding multiple-input multiple-output (MIMO) successive refinement superposition

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source-adaptive power allocation for digital modulation

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IEEE COMMUNICATIONS LETTERS 2003年第12期7卷 569-571页

作者： Görtz, N Bresch, E Tech Univ Munich Inst Commun Engn D-80290 Munich Germany

A novel joint source channel-coding technique called source-adaptive power allocation is introduced for the transmission of continuous-amplitude waveform source samples over a noisy channel. Starting from a binary or quaternary digital Modulation scheme we apply a power control, which depends on the uniquantized source samples, to the modulation signal points before they are transmitted over the channel. The resulting system shows strongly superior performance compared with conventional schemes.

关键词： joint source-channel coding power allocation source-adaptive modulation

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Near-Optimal Nonbinary Index Assignment for Equiprobable Lattice Quantizers

IEEE OPEN JOURNAL OF THE COMMUNICATIONS SOCIETY

引用

IEEE OPEN JOURNAL OF THE COMMUNICATIONS SOCIETY 2023年 4卷 1350-1370页

作者： Yao, Yunxiang Mow, Wai Ho Hong Kong Univ Sci & Technol Dept Elect & Comp Engn Hong Kong Peoples R China

Index assignment (IA) is a low-complexity joint source-channel coding technique that has the potential for use in low-latency and low-power applications, such as wireless sensor networks (WSNs). Though binary IA has been extensively studied for assigning binary indices to quantized codewords (or symbols) under the assumption of binary symmetric channels (BSCs), real-world scenarios often use M-ary modulations. Directly applying binary IAs designed for BSCs to M-ary modulations results in suboptimal performance. In this paper, we investigate the M-ary IA, which assigns M-ary labels to quantized codewords (or symbols), assuming the use of a equiprobable lattice quantizer. For such a system, we derive a tight performance bound and propose a near-optimal IA scheme based on a two-step design. In addition, we propose explicit IA constructions for practical modulation schemes, including PAM, QAM, and PSK. Our proposed IA design is rigorously proven to be optimal for 3-PSK and QPSK, whereas for larger modulation orders, the proposed IA constructions approach the bounds within small gaps. Our simulations show that the constructed IA scheme can achieve significant energy savings compared to the conventional binary IA scheme. Specifically, in some WSN scenarios, the proposed IA for 16-QAM is shown to achieve significant reductions in energy consumption relative to the conventional binary counterpart.

关键词： Discrete memoryless channel index assignment joint source-channel coding quantization

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A joint source-channel speech coder using hybrid digital-analog (HDA) modulation

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IEEE TRANSACTIONS ON SPEECH AND AUDIO PROCESSING 2002年第4期10卷 222-231页

作者： Phamdo, N Mittal, U SUNY Stony Brook Dept Elect & Comp Engn Stony Brook NY 11794 USA

A joint source-channel coding system for transmitting speech on a bandlimited additive white Gaussian noise (AWGN) channel is presented. The proposed method uses a hybrid of digital and analog modulation techniques. The digital part of the system consists of a Federal Standard 1016 Code-Excited Linear Predictive (FS 1016 CELP) speech coder followed by a rate-3/5 parallel concatenated (turbo) error correcting code. The analog part, which transmits the quantization error due to the FS 1016 CELP coder, consists of a linear encoder and decoder. The advantage of the proposed system is that it achieves excellent rate-distortion/capacity performance that is common in digital systems while maintaining a "graceful degradation" characteristic that is common in analog systems. Comparisons are made with three purely digital systems and an analog system-with all systems operating at the same overall rate. A formal listening test shows that, at high channel SNR, the improved performance of the proposed hybrid system (versus the purely digital systems) is noticeable to the average listener. Finally, an informal listening test indicates that at low channel SNR (where the error correcting code breaks down) the decoded speech of the hybrid system is still intelligible.

关键词： joint source-channel coding robustness speech coding

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