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Linear filtering methods for fixed rate quantisation with noisy symmetric error channels

IET SIGNAL PROCESSING 2013年第9期7卷 888-896页

作者： Thiagarajan, Ganesan Murthy, Chandra Ramabhadra Indian Inst Sci Dept ECE Bangalore 560012 Karnataka India

This study considers linear filtering methods for minimising the end-to-end average distortion of a fixed-rate source quantisation system. For the source encoder, both scalar and vector quantisation are considered. The codebook index output by the encoder is sent over a noisy discrete memoryless channel whose statistics could be unknown at the transmitter. At the receiver, the code vector corresponding to the received index is passed through a linear receive filter, whose output is an estimate of the source instantiation. Under this setup, an approximate expression for the average weighted mean-square error (WMSE) between the source instantiation and the reconstructed vector at the receiver is derived using high-resolution quantisation theory. Also, a closed-form expression for the linear receive filter that minimises the approximate average WMSE is derived. The generality of framework developed is further demonstrated by theoretically analysing the performance of other adaptation techniques that can be employed when the channel statistics are available at the transmitter also, such as joint transmit-receive linear filtering and codebook scaling. Monte Carlo simulation results validate the theoretical expressions, and illustrate the improvement in the average distortion that can be obtained using linear filtering techniques.

关键词： source encoder average distortion linear filters Quantization encoder instantiation Vector quantization Receivers Memoryless channel

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Remote control over noisy communication channels: A first-order example

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IEEE TRANSACTIONS ON AUTOMATIC CONTROL 2007年第2期52卷 284-289页

作者： Sarma, Sridevi V. Dahleh, Munther A. MIT Dept Elect Engn Cambridge MA 02139 USA

In this note, we consider a set up in which the plant and controller-are local to each other, but are together driven by a remote reference signal that is transmitted through a noisy discrete channel. Our goal is to design codeword lengths of block source and channel encoders, and a controller to meet a model matching performance objective. Such design problems are difficult in general, as there is a strong interplay between control objectives and communication constraints, which forces the synthesis of controllers and encoder-decoder pairs to be done simultaneously. Current approaches typically fix one, while the other is designed to meet some objective. We first construct a model matching performance metric that captures the tradeoffs between coding the reference command to achieve more accuracy at the remote site and designing a controller to meet performance. We then simultaneously synthesize the controller and encoder codeword lengths that meet the specified objective for a first-order plant and model case. Finally, we illustrate performance sensitivity to the poles of the plant and model, and to the channel noise.

关键词： channel decoder channel encoder communication channel remote control source encoder

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Multi-layer transmission and hybrid relaying for relay channels with multiple out-of-band relays

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TRANSACTIONS ON EMERGING TELECOMMUNICATIONS TECHNOLOGIES 2014年第9期25卷 895-904页

作者： Park, Seok-Hwan Simeone, Osvaldo Sahin, Onur Shamai (Shitz), Shlomo New Jersey Inst Technol Ctr Wireless Commun & Signal Proc Res ECE Dept Newark NJ 07102 USA InterDigital Inc Melville NY 11747 USA Technion Israel Inst Technol Dept Elect Engn IL-32000 Haifa Israel

In this work, a relay channel is studied in which a source encoder communicates with a destination decoder through a number of out-of-band relays that are connected to the decoder through capacity-constrained digital backhaul links. This model is motivated by the uplink of cloud radio access networks. In this scenario, a novel transmission and relaying strategies are proposed in which multi-layer transmission is used, on the one hand, to adaptively leverage the different decoding capabilities of the relays and, on the other hand, to enable hybrid decode-and-forward and compress-and-forward relaying. The hybrid relaying strategy allows each relay to forward part of the decoded messages and a compressed version of the received signal to the decoder. The problem of optimising the power allocation across the layers and the compression test channels is formulated. Albeit non-convex, the derived problem is found to belong to the class of so-called complementary geometric programs. Using this observation, an iterative algorithm based on the homotopy method is proposed that achieves a stationary point of the original problem by solving a sequence of geometric programming, and thus convex, problems. Numerical results are provided that show the effectiveness of the proposed multi-layer hybrid scheme in achieving performance close to a theoretical (cutset) upper bound. Copyright (c) 2013 John Wiley & Sons, Ltd.

关键词： source encoder original problem relay relaying GEOMETRIC PROGRAMMING homotopy method equilibrium point decoders hybrid decoding relay channel layered transmission

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Real-Time Communication of Dependent Messages

Real-Time Communication of Dependent Messages

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27th Queen's Biennial Symposium on Communications (QBSC)

作者： Cheng, Zhong Mao, Yongyi Chan, Terence Univ Ottawa Sch EECS Ottawa ON Canada Univ S Australia Inst Telecommun Res Adelaide SA 5001 Australia

ISBN: (纸本)9781479939725

This paper presents a source model to capture the dependency structure of messages generated by a source encoder. Under such a model, the communication problem subject to certain delay constraint may be formulated as a utility maximization problem. Over discrete memoryless channels, we derive the expression of maximal achievable utility, which appears to be governed by the channel coding theorem. We perform numerical study of two examples of source-coded messages, corresponding to layered codes and multiple description codes respectively, and show the impact of delay and channel condition on their respective achievable utilities.

关键词： Messages source encoder WebRTC able to communicate realizable Memoryless channel Codes

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JOINT source-CHANNEL CODING OF 3D VIDEO USING MULTIVIEW CODING

JOINT SOURCE-CHANNEL CODING OF 3D VIDEO USING MULTIVIEW CODI...

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IEEE International Conference on Acoustics, Speech, and Signal Processing

作者： Arash Vosoughi Vanessa Testoni Pamela Cosman Laurence Milstein ECE University of California San Diego

ISBN: (纸本)9781479903573

We consider the joint source-channel coding problem of a 3D video transmitted over an AWGN channel. The goal is to minimize the total number of bits, which is the sum of the number of source bits and the number of forward error correction bits, under two constraints: the quality of the primary view and the quality of the secondary view must be greater than or equal to a predetermined threshold at the receiver. The quality is measured in terms of the expected PSNR of an entire decoded group of pictures. A MVC (multiview coding) encoder is used as the source encoder, and rate compatible punctured turbo codes are utilized for protection of the encoded 3D video over the noisy channel. Equal error protection and unequal error protection are compared for various 3D video sequences and noise levels.

关键词： Joint source-channel coding Multiview video coding Turbo codes Unequal error protection error protection Combined source-channel coding turbo codes source encoder Video coding Videotapes Drill bits Joints Forward error correction Greater than or equal to

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A Robust Communication System Based on Joint-source Channel Coding for a Uniform source

A Robust Communication System Based on Joint-Source Channel ...

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IEEE Vehicular Technology Conference

作者： Hieu T. Nguyen Tor A. Ramstad Ilangko Balasingham Department of Electronics and Telecommunications NTNU Interventional Center Rikshospitalet University Hospital nstitute of Clinical Medicine University of Oslo

ISBN: (纸本)9781467318808

A communication system based on the joint source-channel coding principle is proposed where a fixed-rate source encoder using neither a codebook nor an entropy encoder is exploited to avoid the error propagation effect and thus gain in system robustness. An explicit expression of the mean square error (MSE) distortion of the system for a uniform source is derived. Based on the MSE distortion, the optimal design of the communication system under the total transmission rate constraint is formulated as a mixed integer nonlinear optimization problem. We provide an algorithm to achieve the optimal solution via a convex optimization solver. The numerical result shows that the overall performance of the proposed system is close to the performance of the entropy coding scalar quantizer (ECSQ) system established by A. Gyorgy and T. Linder [1] for almost all rate regions.

关键词： Scalar quantizer Uniformly distributed source Joint source-channel coding Mean square error distortion Fixed-length source encoder Subchannel COMMUNICATION SYSTEMS Mean square error Error propagation Communication Research Channel coding codebook Convex function Uniform Uniforms optimal solution source encoder Combined source-channel coding abnormal shapes

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Exploiting Padding Bits for Improvement of Channel Decoder Performance

Exploiting Padding Bits for Improvement of Channel Decoder P...

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IEEE Global Communications Conference

作者： Yoshito Watanabe Hideki Ochiai Department of Electrical and Computer Engineering Yokohama National University

ISBN: (纸本)9781479959532

In most practical communication systems where the source encoder is followed by the channel encoder, there is some mismatch between the length of the bits from the source encoder and that fed into the channel encoder. Therefore, dummy bits are usually padded to the source coded bits so as to fill the gap, and these padded bits are usually discarded after channel decoding at the receiver. In this paper, considering the padding event at the transmitter side as a probabilistic event, a novel integrated decoder that detects the zero padding (ZP) sequence together with the trellis pruning technique is proposed assuming that the turbo code is used as a channel code. The performance depends on how these padded bits are allocated in the information sequences, and two representative approaches, referred to as consecutive zero padding (CZP) and sparse zero insertion (SZI), are introduced. Through the EXIT chart analysis, it is shown that the latter approach results in considerably better performance than the former due to the effect of trellis pruning. Furthermore, simulation results show that the proposed decoder can improve the throughput of the system in comparison with the conventional system where the padding bits simply reduce the effective throughput.

关键词： source encoder channel encoder Channel Decoder Drill bits COMMUNICATION SYSTEMS zero padding turbo codes Throughput decoders

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Efficient Compression of Noisy Sparse sources Based on Syndrome Encoding

Efficient Compression of Noisy Sparse Sources Based on Syndr...

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IEEE Global Communications Conference

作者： Ahmed Elzanaty Andrea Giorgetti Marco Chiani DEI Univ. of Bologna Bologna Italy

ISBN: (纸本)9781509013296

Signal compression is essential for energy and bandwidth efficient communication and storage systems. In this paper, we provide two practical approaches for source compression of noisy sparse and non-strictly sparse (compressible) sources. The proposed schemes are based on channel coding theory to construct a source encoder that decreases the number of transmitted bits while preserving the fidelity of the reconstructed signal at the receiver by exploiting its sparsity. In addition, a model order selection scheme is proposed to detect the non-zero elements of sparse vectors embedded in noise, or to find a nonlinear sparse approximation of compressible signals. As illustrated by numerical results, our approach provides a lower distortion-rate function compared to previously known methods. For example, the proposed schemes achieve a lower distortion, about 2 orders of magnitude, compared to compressed sensing, for the same rate.

关键词： Noise measurement Encoding Nonlinear distortion Quantization (signal) Sparse matrices Data models Receivers Nonlinear distortion Noise measurement Sparse matrix data models Receivers coding source encoder Noise source compression signal compression practical methods

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source-CHANNEL CODING APPROACH TO GENERATE TAMPER-PROOF IMAGES

SOURCE-CHANNEL CODING APPROACH TO GENERATE TAMPER-PROOF IMAG...

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IEEE International Conference on Acoustics, Speech and Signal Processing

作者： Saeed Sarreshtedari Mohammad Ali Akhaee School of Electrical and Computer Eng. College of Eng. University of Tehran Tehran Iran

ISBN: (纸本)9781479928941

Watemarking the original images to protect them against tampering has recently attracted an overgrowing interest. Recent works in this field offer algorithms that not only localize the tampering, but also recover the original content in the lost area. In this paper, we show that this self-restoration problem can be modeled as a source-channel coding problem. The original image is compressed using an efficient source encoder. The output is then channel coded to be capable of tolerating a certain rate of tampering. At the receiver, decoder reveals the encoder output bit stream if the tampering is below the certain limit. Decoder exploits the location of the erased blocks at the decoding, which are known thanks to the embedded check bits. The output of the source decoder is then used to replace the content of the tampered area. We show that approaching the self-restoration problem from this general viewpoint, the performance is significantly improved comparing to the state of the art schemes, in terms of the quality of watermarked image, quality of the restored content, and tolerable tampering rate.

关键词： state of the art original image decoders images Output source encoder DECODING Image quality bit stream

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