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Genetic Algorithm Aided Design of Component Codes for Irregular Variable Length coding

IEEE TRANSACTIONS ON COMMUNICATIONS 2009年第5期57卷 1290-1297页

作者： Maunder, R. G. Hanzo, L. Univ Southampton ECS Southampton SO17 1BJ Hants England

In this paper we propose a novel Real-Valued Free Distance Metric (RV-FDM) for comparing the error correction capabilities of Variable Length Error Correction (VLEC) codebooks that have the same integer-valued free distance lower bounds. We demonstrate that VLEC codebooks having higher RV-FDMs tend to have EXtrinsic Information Transfer (EXIT) functions with more pronounced 'S'-shapes. Furthermore, we show that higher-accuracy EXIT chart matching can be achieved if the component EXIT functions of an irregular code exhibit more variety. This motivates the employment of our novel genetic algorithm for designing the component VLEC codes of irregular variable length coding, that have particular EXIT functions, in addition to exhibiting desirable bit entropies and decoding complexities.

关键词： Variable length codes joint source and channel coding trellis codes information rates

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Power-minimized bit allocation for video communication over wireless channels

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IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY 2002年第6期12卷 398-410页

作者： Zhang, Q Ji, Z Zhu, WW Zhang, YQ Microsoft Res Asia Wireless & Networking Grp Beijing 100080 Peoples R China

Video communication over wireless links using handheld devices is a challenging task due to the time-varying characteristics of the wireless channels and limited battery resources. Rate-distortion (R-D) analysis plays a key role in video coding and communication systems, and usually R-D relation does not assume any power constraint. In this paper, we investigate the relations of rate, distortion, and power consumption. Based on those relations, we propose a power-minimized bit-allocation scheme considering the processing power for source coding and channel coding, as well as the transmission power jointly. In this scheme, the total bits are allocated between source and channel coders, according to wireless channel conditions and video quality requirements, to minimize the total power consumption for a single user and a group of users in a cell, respectively. Simulation results show that our proposed joint power-control and bit-allocation scheme achieves high power savings compared to the conventional scheme.

关键词： bit allocation joint source and channel coding power consumption power control power-rate relation rate-distortion relation UEP wireless networks

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Probabilistic Shaping for Protograph LDPC-Coded Modulation by Residual source Redundancy

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IEEE TRANSACTIONS ON COMMUNICATIONS 2021年第7期69卷 4267-4281页

作者： Chen, Chen Chen, Qiwang Wang, Lin He, Yu-Cheng Chen, Yifan Huaqiao Univ Sch Informat Sci & Engn Xiamen Key Lab Mobile Multimedia Commun Xiamen 361021 Peoples R China Xiamen Univ Dept Commun Engn Xiamen 361005 Peoples R China Univ Waikato Sch Engn Hamilton 3216 New Zealand

Probabilistic amplitude shaping (PAS) has proved to be a promising way to achieve the shaping gain for an additive white Gaussian noise channel with a distribution matcher (DM). However, the DM schemes may suffer a rate loss and increase both complexity and latency, when they are not suited for the input bit stream with redundancy. In this paper, a novel PAS strategy is proposed for a joint source and channel coded modulation system, where the residual source redundancy after source coding can be exploited to obtain both shaping and coding gains. It is shown that the residual source redundancy can be controlled by choosing the row weight distribution for source code, thus making the probability distribution of the modulated symbols be optimized under an appropriate interleaver design. To guarantee the error-floor performance, the source code is constrained by predicting the probability distribution of source bits within target finite-length frames. By jointly designing source and channel codes, the residual source redundancy can also be exploited to achieve the coding gain. Compared with the state-ofthe-art code pairs, the proposed code pairs have better error-floor performance, and achieve higher coding and shaping gains without suffering from the rate-loss and the latency caused by DM.

关键词： Coded modulation joint source and channel coding probabilistic amplitude shaping protograph LDPC codes residual source redundancy

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Evolutionary Algorithm Aided Interleaver Design for Serially Concatenated Codes

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IEEE TRANSACTIONS ON COMMUNICATIONS 2011年第7期59卷 1753-1758页

作者： Maunder, R. G. Hanzo, L. Univ Southampton Sch Elect & Comp Sci Southampton SO17 1BJ Hants England

Previous interleavers designed for Serially Concatenated Codes (SCCs) have achieved a limited Minimum Hamming Distance (MHD) between the legitimate permutations of the encoded bit sequence. Hence, we propose a novel Evolutionary Algorithm (EA) capable of designing improved interleavers for SCCs, without artificially limiting the achievable MHD. As a result, increased MHDs and therefore reduced error floors are achieved, even if only a modest EA complexity can be afforded.

关键词： joint source and channel coding trellis codes information rates

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Clustering source output bits and equalizing bit error sensitivity to improve the quality and robustness of transmitted images over wireless channels

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SIGNAL PROCESSING-IMAGE COMMUNICATION 2003年第10期18卷 947-956页

作者： Fang, JT Shyu, WL Wu, CS Chen, KJ Natl Chung Cheng Univ Dept Elect Engn Chiayi 621 Taiwan

A joint design of source coding and channel coding is proposed to transmit images over error-prone wireless channels. First, the importance of each source output bit is quantified in bit error sensitivity (BES). Next, clustered set partitioning in hierarchical trees (C-SPIHT) is adopted to cluster SPIHT output bits so that the resultant bit-clusters have distinct BES. Then, we prove that equalizing the mean BES of bit-clusters provides the optimal assignment of channel coding rates for the unequal error protection. Besides, to achieve the best PSNR performance under a transmission rate, we use a heuristic method to allocate the source coding rate and channel coding rate. Simulation results show that, under different channel bit error rates, our design not only improves the mean PSNR performance, but also reduces the variations of PSNR performance, i.e. the robustness of PSNR to the channel noise interference is improved. (C) 2003 Published by Elsevier B.V.

关键词： wireless multimedia communications joint source and channel coding rate-distortion bit error sensitivity unequal error protection

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joint iterative decoding of trellis-based VQ and TCM

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IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2007年第4期6卷 1327-1336页

作者： Maunder, R. G. Kliewer, J. Ng, S. X. Wang, J. Yang, L.-L. Hanzo, L. Univ Southampton Sch ECS Southampton SO17 1BJ Hants England

A joint video and channel coded system employing an iteratively decoded serial concatenation of a Vector Quantization (VQ) based video codec and a Trellis-Coded Modulation (TCM) scheme is proposed. The video codec imposes VQ-induced code constraints, which may be completely described by a trellis structure, which is employed as the basis for optimal minimum mean-squared-error VQ-encoding and -decoding. In the latter case, the Bahl-Cocke-Jelinek-Raviv (BCJR) algorithm is employed to facilitate the iterative exchange of soft information between the VQ and TCM decoder. An error-free video reconstruction quality is supported using 16-level Quadrature Amplitude Modulation (16QAM) based TCM for transmission over Rayleigh-fading channels at a Signal-to-Noise Ratio (SNR) per bit of 5.25 dB. This value is within 1.29 dB of the Rayleigh channel's capacity at (our system's effective bandwidth-efficiency of 2 bits/s/Hz. Owing to its ability to exploit the VQ-induced code constraints during iterative decoding, the joint video and channel coding approach is found to consistently outperform the Shannonian source and channel separation philosophy. This is achieved at the cost of a 1.6 times higher computational complexity. Finally, the convergence of the iterative decoder is investigated with the aid of a novel so-called EXtrinsic Information Transfer (EXIT) chart.

关键词： video coding vector quantization joint source and channel coding trellis codes BCJR

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Information and signal processing for sensor networks

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IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES 2004年第10期E87A卷 2599-2606页

作者： Ogawa, A Yamazato, T Ohtsuki, T Meijo Univ Dept Informat Engn Nagoya Aichi 4688502 Japan Nagoya Univ Ctr Informat Media Studies Nagoya Aichi 4648603 Japan Tokyo Univ Sci Dept Elect Engn Noda Chiba 2788510 Japan

Sensor networks, in which a large number of sensor nodes are connected with each other through communication networks, are potential to provide extensive new applications with various research and technical challenges and attracting much attention all over the world. In this paper we describe information and signal processing for sensor networks with emphasis on the concepts of collaboration and fusion as one of the most important issues for the sensor networks. We also review some basic aspects of sensor networks in terms of their features and the network architecture.

关键词： sensor networks collaborative infonnation and signal processing joint source and channel coding deterministic and statistic collaboration cooperative diversity

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A unified architecture for real-time video-coding systems

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IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY 2003年第6期13卷 472-487页

作者： Li, ZG Zhu, C Ling, N Yang, XK Feng, GN Wu, S Pan, F Inst InfoComm Res Div Med Singapore 119613 Singapore Nanyang Technol Univ Sch Elect & Elect Engn Singapore 639798 Singapore Santa Clara Univ Dept Comp Engn Santa Clara CA 95053 USA

This paper presents a unified architecture for a live video over the Internet with emphasis on solving some challenging problems such as network bandwidth adaptation for rate and congestion, loss packet recovery, joint source and channel coding, and packetization. In our architecture, a time-varying bit rate for the source coding and time-varying ratios for the channel coding are simultaneously computed by a new congestion-control protocol. An adaptive rate-control scheme is then proposed to calculate quantization parameters and to determine the number of skipping frames corresponding to the bit rate. An adaptive unequal error-control scheme is also provided to protect the bitstream. Furthermore, a simple and MPEG-4 standard compatible algorithm is designed to packetize generated bitstream at the SyncLayer by using the existing resynchronization marker approach. With the proposed architecture, the coding efficiency and the robustness of the whole system are improved greatly.

关键词： adaptive rate control congestion control joint source and channel coding packetization unequal error control video over the Internet

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Error-resilient transmission of 3D models

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ACM TRANSACTIONS ON GRAPHICS 2005年第2期24卷 182-208页

作者： Alregib, G Altunbasak, Y Rossignac, J Georgia Inst Technol Sch Elect & Comp Engn Savannah GA 31407 USA Georgia Inst Technol Sch Elect & Comp Engn Atlanta GA 30332 USA Georgia Inst Technol Coll Comp Atlanta GA 30332 USA

In this article, we propose an error-resilient transmission method for progressively compressed 3D models. The proposed method is scalable with respect to both channel bandwidth and channel packet-loss rate. We jointly design source and channel coders using a statistical measure that (i) calculates the number of both source and channel coding bits, and (ii) distributes the channel coding bits among the transmitted refinement levels in order to maximize the expected decoded model quality In order to keep the total number of bits before and after applying error protection the same, we transmit fewer triangles in the latter case to accommodate the channel coding bits. When the proposed method is used to transmit a typical model over a channel with a 10% packet-loss rate, the distortion (measured using the Hausdorff distance between the original and the decoded models) is reduced by 50% compared to the case when no error protection is applied.

关键词： algorithms experimentation performance reliability 3D graphics compression error resilience joint source and channel coding media streaming priority encoding transmission progressive transmission unequal error protection virtual reality over IP

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Cross-layer architecture for scalable video transmission in wireless network

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SIGNAL PROCESSING-IMAGE COMMUNICATION 2007年第3期22卷 317-330页

作者： Huusko, J. Vehkapera, J. Amon, P. Lamy-Bergot, C. Panza, G. Peltola, J. Martini, M. G. VTT Tech Res Ctr Finland Oulu Finland Siemens Corp Technol Munich Germany Thales Commun Colombes France Politecn Milan CEFRIEL I-20133 Milan Italy Univ Bologna CNIT I-40126 Bologna Italy

Multimedia applications such as video conference, digital video broadcasting (DVB), and streaming video and audio have been gaining popularity during last years and the trend has been to allocate these services more and more also on mobile users. The demand of quality of service (QoS) for multimedia raises huge challenges on the network design, not only concerning the physical bandwidth but also the protocol design and services. One of the goals for system design is to provide efficient solutions for adaptive multimedia transmission over different access networks in all-IP environment. The joint source and channel coding (JSCC/D) approach has already given promising results in optimizing multimedia transmission. However, in practice, arranging the required control mechanism and delivering the required side information through network and protocol stack have caused problems and quite often the impact of network has been neglected in studies. In this paper we propose efficient cross-layer communication methods and protocol architecture in order to transmit the control information and to optimize the multimedia transmission over wireless and wired IP networks. We also apply this architecture to the more specific case of streaming of scalable video streams. Scalable video coding has been an active research topic recently and it offers simple and flexible solutions for video transmission over heterogeneous networks to heterogeneous terminals. In addition it provides easy adaptation to varying transmission conditions. In this paper we illustrate how scalable video transmission can be improved with efficient use of the proposed cross-layer design, adaptation mechanisms and control information. (c) 2007 Elsevier B.V. All rights reserved.

关键词： scalable video coding (SVC) cross-layer communication design joint source and channel coding multimedia delivery UDP-Lite RTP packetization WLAN link layer scheduling medium access control (MAC)

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