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Soft-input reconstruction of binary transmitted quantized overcomplete expansions

IEEE SIGNAL PROCESSING LETTERS 2004年第11期11卷 899-903页

作者： Kliewer, J Mertins, A Univ Southampton Sch Elect & Comp Engn Commun Res Grp Southampton SO17 1BJ Hants England Carl von Ossietzky Univ Oldenburg Inst Phys Signal Proc Grp D-26111 Oldenburg Germany

In this letter, we propose a soft-decoding method for quantized overcomplete frame expansions that are binary transmitted through noisy channels. The frame expansions can be viewed as real-valued block codes that are directly applied to waveform signals prior to quantization. The explicit redundancy introduced in the continuous amplitude domain is exploited by the decoder in two stages. First, the index-based redundancy is used by a soft-input soft-output source decoding approach that outputs decoded symbols together with their reliability information. In a second stage, the soft information on the symbols and the structure of the introduced redundancy are used to correct errors. The performance of the proposed approach is evaluated for different code constructions based on the discrete Fourier transform (DFT), the discrete cosine transform (DCT), and the discrete Hadamard transform (DHT), and is compared to standard approaches without soft decoding.

关键词： joint source-channel coding overcomplete frame expansions real-valued block codes residual source redundancy

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SparseCast: Hybrid Digital-Analog Wireless Image Transmission Exploiting Frequency-Domain Sparsity

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IEEE COMMUNICATIONS LETTERS 2018年第12期22卷 2451-2454页

作者： Tung, Tze-Yang Gunduz, Deniz Univ Southern Calif Viterbi Sch Engn Los Angeles CA 90089 USA Imperial Coll London Dept Elect & Elect Engn London SW7 2AZ England

A hybrid digital-analog wireless image transmission scheme, called SparseCast, is introduced, which provides graceful degradation with channel quality. SparseCast achieves improved end-to-end reconstruction quality while reducing the bandwidth requirement by exploiting frequency-domain sparsity through compressed sensing. The proposed algorithm produces a linear relationship between the channel signal-to-noise ratio and peak signal-to-noise ratio (PSNR) without requiring the channel state knowledge at the transmitter. This is particularly attractive when transmitting to multiple receivers or over unknown time-varying channels, as the receiver PSNR depends on the experienced channel quality and is not bottlenecked by the worst channel. SparseCast is benchmarked against two alternative algorithms: SoftCast and block CS-smooth projected Landweber (BCS-SPL). Our findings show that the proposed algorithm outperforms SoftCast by approximately 3.5 dB and BCS-SPL by 15.2 dB.

关键词： joint source-channel coding analog transmission compressed sensing

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Adaptive joint source-channel rate allocation policies for delay sensitive applications over fading channels

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IEEE TRANSACTIONS ON INFORMATION THEORY 2006年第12期52卷 5587-5598页

作者： Thejaswi P S, Chandrashekhar Sharma, Vinod Honeywell Technol Solut Lab Res & Technol Div Bangalore Karnataka India Indian Inst Sci Dept Elect Commun Engn Bangalore 560012 Karnataka India

In this correspondence, we consider a problem of optimal source, channel coding rate pair allocation over a wireless link based on the channel fading state and the queue length of the transmitter. The source is delay sensitive. Therefore, our objective is to minimize the mean delay under given mean power and distortion constraints. We show that by jointly optimizing the source and channel rates, one can gain substantially in performance as compared to only source or channel rate optimization, as is usually considered in the literature. This is shown for single user, single-input-single-output (SISO), multiple-input-multiple-output (MIMO), and multiuser systems. The methods used are from Markov decision theory.

关键词： joint source-channel coding Markov decision theory mean distortion constraint multiple-input-multiple-output (MIMO) systems multiple-access channel wireless link

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On the performance of space-time block-coded MIMO video communications

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IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY 2007年第3期56卷 1223-1229页

作者： Lin, Shunan Stefanov, Andrej Wang, Yao Harmonic Inc Video Algorithm Grp White Plains NY 10601 USA Polytech Univ Dept Elect & Comp Engn Brooklyn NY 11201 USA

The problem of efficient video communications over multiple-input-multiple-output (MIMO) wireless systems is of great significance due to the high capacity of the multiple antenna system. The high data rates provided by the MIMO system can be traded off with diversity gain by using different channel-coding schemes. Also, by using different video source-coding methods, high compression gain can be traded off with the error resilience gain. One should jointly consider source coding and channel coding when designing a MIMO wireless video system. However, little is known so far about what combinations of channel-coding and source-coding methods have the best overall performance in a MIMO system. In this paper, by comparing the performances of several different typical combinations through both theoretical and simulation studies, we show that no single combination is the best for the entire range of channel conditions, but rather, different combinations may be best for a subrange.

关键词： diversity error resilience joint source-channel coding layered coding (LC) multiple description coding (MDC) multiple input-multiple output (MIMO) space-time coding video coding

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Efficient rate allocation for progressive image transmission via unequal error protection over finite-state Markov channels

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IEEE TRANSACTIONS ON SIGNAL PROCESSING 2005年第11期53卷 4330-4338页

作者： Liu, ZM Zhao, MY Xiong, ZX Texas A&M Univ Dept Elect Engn College Stn TX 77843 USA New Jersey Inst Technol Dept Elect & Comp Engn Newark NJ 07102 USA

This paper proposes a unified framework for addressing progressive image transmission over noisy channels based on the finite-state Markov channel (FSMC) model. FSMC models are simple yet general enough to model binary symmetric, Gilbert-Elliott, and fading channels. They Allow error sequence analysis that facilitates quantifying the statistical characteristics of the embedded bitstreams transmitted over FSMC in closed form. Using a concatenation of rate-compatible puncturing convolutional code and cyclic redundancy check code for error protection, we use a concatenation of rate-compatible punctured convolutional code and cyclic redundancy check code for error protection, which results in an unequal error protection (UEP) system, and find (sub-)optimal rate allocation solutions for our setup. By mapping fading channels to FSMCs, the JSCC problem is thus solved without the burden of simulations using an image-dependent lookup table. Fast algorithms are proposed to search for the optimal UEP. Experiments on embedded image bitstreams over FSMCs confirm our analytical results.

关键词： finite-state Markov model joint source-channel coding progressive image transmission unequal error protection

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joint source-channel decoding of variable-length codes for convolutional codes and turbo codes

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IEEE TRANSACTIONS ON COMMUNICATIONS 2005年第1期53卷 10-15页

作者： Jeanne, M Carlach, JC Siohan, P France Telecom R&D Div RESA BWA F-35512 Cesson Sevigne France

Several recent publications have shown that joint source-channel decoding could be a powerful technique to take advantage of residual source redundancy for fixed- and variable-length source codes. This letter gives an in-depth analysis of a low-complexity method recently proposed by Guivarch et al, where the redundancy left by a Huffman encoder is used at a bit level in the channel decoder to improve its performance. Several simulation results are presented, showing for two first-order Markov sources of different sizes that using a priori knowledge of the source statistics yields a significant improvement, either with a Viterbi channel decoder or with a turbo decoder.

关键词： convolutional codes (CCs) joint source-channel coding turbo codes (TCs) variable-length codes (VLCs)

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An unequal error protection scheme for reliable peer-to-peer scalable video streaming

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JOURNAL OF VISUAL COMMUNICATION AND IMAGE REPRESENTATION 2016年 38卷 790-801页

作者： Lo, Chi-Wen Zhou, Chao Lin, Chia-Wen Chen, Yung-Chang Ind Technol Res Inst Informat & Commun Res Labs Hsinchu Taiwan Peking Univ Inst Comp Sci & Technol Beijing 100871 Peoples R China Natl Tsing Hua Univ Dept Elect Engn Hsinchu 30013 Taiwan

This paper proposes an unequal error protection (UEP) scheme for transporting scalable video packets over packet-lossy peer-to-peer networks. In our scheme, given an estimated system uplink capacity, a receiver-driven joint source-channel coding (JSCC) mechanism is proposed by which each child-peer minimizes the received visual distortion by subscribing to appropriate numbers of source and channel coding packets. Because the bandwidth for inter-peer transmissions may fluctuate largely due to peer dynamics, in our method, a peer estimates the available system uplink capacity based on consensus propagation to avoid the fluctuating allocations of JSCC. To efficiently utilize the uplink bandwidth of peers, parent-peers utilize sender-driven contribution-guided peer selection to reject the low-contribution subscriptions requested from candidate child-peers. Simulation results demonstrate that our method significantly improves the visual quality, compared to other state-of-the-art schemes. (C) 2016 Elsevier Inc. All rights reserved.

关键词： Video streaming Peer-to-peer streaming Scalable video coding joint source-channel coding Unequal error protection

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Comparison of Practical Feedback Algorithms for Multiuser MIMO

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IEEE TRANSACTIONS ON COMMUNICATIONS 2010年第8期58卷 2436-2446页

作者： Shanechi, Maryam Modir Porat, Ron Erez, Uri MIT Dept Elect Engn & Comp Sci Cambridge MA 02139 USA Tel Aviv Univ Dept Elect Engn Ramat Aviv Israel

We consider the problem of obtaining channel state information (CSI) via a fast feedback link for transmission on the downlink of a multiuser MIMO system. We examine the relative merits of channel feedback schemes based on Shannon's source-channel separation principle (digital schemes) and non-separation based schemes and show that the latter are preferable in this application when small to moderate bandwidth expansion ratios are used as in many current cellular systems. For comparison, we first compute upper-bounds on the performance of the system as a function of SNR. For the non-separation based schemes, we first consider a simple analog transmission and then develop a hybrid digital-analog transmission scheme which quantizes the CSI using a few bits and sends these bits and also the quantization error using analog transmission. We show that the hybrid scheme achieves a higher throughput compared to both analog and digital transmissions and has a much lower computational complexity compared to a digital scheme.

关键词： MIMO systems channel state information (CSI) feedback joint source-channel coding multiuser MIMO analog feedback

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Rate-Distortion-Perception Optimized Neural Speech Transmission System for High-Fidelity Semantic Communications

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SENSORS 2024年第10期24卷 3169页

作者： Yao, Shengshi Xiao, Zixuan Niu, Kai Beijing Univ Posts & Telecommun Key Lab Universal Wireless Commun Beijing 100876 Peoples R China Peng Cheng Lab Dept Broadband Commun Shenzhen 518066 Peoples R China

We consider the problem of learned speech transmission. Existing methods have exploited joint source-channel coding (JSCC) to encode speech directly to transmitted symbols to improve the robustness over noisy channels. However, the fundamental limit of these methods is the failure of identification of content diversity across speech frames, leading to inefficient transmission. In this paper, we propose a novel neural speech transmission framework named NST. It can be optimized for superior rate-distortion-perception (RDP) performance toward the goal of high-fidelity semantic communication. Particularly, a learned entropy model assesses latent speech features to quantify the semantic content complexity, which facilitates the adaptive transmission rate allocation. NST enables a seamless integration of the source content with channel state information through variable-length joint source-channel coding, which maximizes the coding gain. Furthermore, we present a streaming variant of NST, which adopts causal coding based on sliding windows. Experimental results verify that NST outperforms existing speech transmission methods including separation-based and JSCC solutions in terms of RDP performance. Streaming NST achieves low-latency transmission with a slight quality degradation, which is tailored for real-time speech communication.

关键词： speech transmission joint source-channel coding semantic communications

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New Hybrid Digital/Analog Schemes for Transmission of a Gaussian source Over a Gaussian channel

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IEEE TRANSACTIONS ON INFORMATION THEORY 2010年第12期56卷 6014-6019页

作者： Gao, Yang Tuncel, Ertem Univ Calif Riverside Dept Elect Engn Riverside CA 92521 USA

Two new schemes are proposed for transmitting a Gaussian source over a Gaussian channel. These schemes directly generalize previous results of Bross et al. and Puri et al. A scaled version of either the source itself or the quantization error is superimposed on the digital information, and thus serves as effective channel state information (CSI) unknown to the receiver. It is shown that for any power allocation between the coded and uncoded components of transmission, optimal distortion can be achieved by a continuum of auxiliary random variables (rather than only Costa's) if the decoded auxiliary codeword is properly used. This observation provides a new degree of freedom in point-to-point transmission. This freedom, in turn, can be utilized in multiterminal scenarios, as is demonstrated with an example.

关键词： AWGN channels hybrid digital/analog coding joint source-channel coding uncoded transmission writing on dirty paper

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