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Successive refinement via broadcast: Optimizing expected distortion of a Gaussian source over a Gaussian fading channel

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IEEE TRANSACTIONS ON INFORMATION THEORY 2008年第7期54卷 2903-2918页

作者： Tian, Chao Steiner, Avi Shamai (Shitz), Shlomo Diggavi, Suhas N. Ecole Polytech Fed Lausanne Sch Comp & Commun Sci CH-1015 Lausanne Switzerland Technion Israel Inst Technol Dept Elect Engn IL-32000 Haifa Israel

We consider the problem of transmitting a Gaussian source on a slowly fading Gaussian channel, subject to the mean-squared error distortion measure. The channel state information is known only at the receiver but not at the transmitter. The source is assumed to be encoded in a successive refinement (SR) manner, and then transmitted over the channel using the broadcast strategy. In order to minimize the expected distortion at the receiver, optimal power allocation is essential. We propose an efficient algorithm to compute the optimal solution in linear time O (M), when the total number of possible discrete fading states is M. Moreover, we provide a derivation of the optimal power allocation when the fading state is a continuum, using the classical variational method. The proposed algorithm as well as the continuous solution is based on an alternative representation of the capacity region of the Gaussian broadcast channel.

关键词： broadcast strategy joint source-channel coding power allocation successive refinement (SR)

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On source Transmission Over MIMO channels With Limited Feedback

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IEEE TRANSACTIONS ON SIGNAL PROCESSING 2009年第1期57卷 324-341页

作者： Kim, Tung T. Skoglund, Mikael Caire, Giuseppe Royal Inst Technol Sch Elect Engn Stockholm Sweden Royal Inst Technol Sch Elect Engn S-10044 Stockholm Sweden Royal Inst Technol ACCESS Linnaeus Ctr S-10044 Stockholm Sweden Univ So Calif Dept Elect Engn Los Angeles CA 90089 USA

The problem of source-channel coding over a multiple-antenna (MIMO) channel with quantized channel state information at the transmitter (CSIT) is considered. Upper bounds on the distortion exponents achieved with partial CSIT under a long-term power constraint are developed. It is shown that the distortion exponent with perfect CSIT grows unbounded as the ratio between the channel and source bandwidth increases, while the exponent achieved with any feedback link of fixed, finite resolution is bounded above by a polynomial of the product between the number of transmit and number of receive antennas. The resolution of the feedback link should grow with the bandwidth ratio to make the distortion exponent scale as fast as that in the perfect-CSIT case. We show that in order to achieve the optimal scaling the CSIT feedback resolution must grow logarithmically with the bandwidth ratio for MIMO channels, and faster than linear for the single-input single-output channel. The achievable distortion exponent of some hybrid schemes with heavily quantized feedback is also derived. The results demonstrate that dramatic performance improvement over the case of no CSIT can be achieved by combining simple schemes with a very coarse CSIT feedback.

关键词： Diversity-multiplexing tradeoff joint source-channel coding large-deviation analysis MIMO systems

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State amplification

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IEEE TRANSACTIONS ON INFORMATION THEORY 2008年第5期54卷 1850-1859页

作者： Kim, Young-Han Sutivong, Arak Cover, Thomas M. Stanford Univ Dept Elect Engn Stanford CA 94305 USA Stanford Univ Dept Stat Stanford CA 94305 USA

We consider the problem of transmitting data at rate R over a state-dependent channel p (y vertical bar x, s) with state information available at the sender and at the same time conveying the information about the channel state itself to the receiver. The amount of state information that can be learned at the receiver is captured by the mutual information I(S-n;Y-n) between the state sequence S-n and the channel output Y-n. The optimal tradeoff is characterized between the information transmission rate R and the state uncertainty reduction rate Delta, when the state information is either causally or noncausally available at the sender. In particular, when state transmission is the only goal, the maximum uncertainty reduction rate is given by Delta* = max(p(x vertical bar s)) I(X S;Y). This result is closely related and in a sense dual to a recent study by Merhav and Shamai, which solves the problem of masking the state information from the receiver rather than conveying it.

关键词： capacity causal state information channels with state information joint source-channel coding noncausal state information state amplification state uncertainty reduction writing on dirty paper

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A Derivation of the source-channel Error Exponent Using Nonidentical Product Distributions

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IEEE TRANSACTIONS ON INFORMATION THEORY 2014年第6期60卷 3209-3217页

作者： Tauste Campo, Adria Vazquez-Vilar, Gonzalo Guillen i Fabregas, Albert Koch, Tobias Martinez, Alfonso Univ Pompeu Fabra Dept Informat & Commun Technol Barcelona 08018 Spain Univ Pompeu Fabra Dept Informat & Commun Technol Inst Catalana Recerca & Estudis Avancats Barcelona 08018 Spain Univ Cambridge Dept Engn Cambridge CB2 1PZ England Univ Carlos III Madrid Signal Theory & Commun Dept Leganes 28911 Spain

This paper studies the random-coding exponent of joint source-channel coding for a scheme where source messages are assigned to disjoint subsets (referred to as classes), and codewords are independently generated according to a distribution that depends on the class index of the source message. For discrete memoryless systems, two optimally chosen classes and product distributions are found to be sufficient to attain the sphere-packing exponent in those cases where it is tight.

关键词： joint source-channel coding reliability function random coding product distributions sphere-packing bound

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Optimal Design of joint Protomatrix for DP-LDPC Codes-Based JSCC System Over on-Body channel

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IEEE ACCESS 2021年 9卷 33091-33101页

作者： Song, Dan Wang, Lin Chen, Qiwang Chen, Guanrong Xiamen Univ Dept Informat & Commun Engn Xiamen 361005 Peoples R China Huaqiao Univ Xiamen Key Lab Mobile Multimedia Commun Xiamen 361021 Peoples R China City Univ Hong Kong Dept Elect Engn Hong Kong Peoples R China

A high-quality data transmission scheme in wireless body area networks is implemented by a joint source-channel coding (JSCC) system with M-ary differential chaos shift keying modulation over an on-body channel. Current DP-LDPC code pairs, which have shown good bit-error ratio performance over additive white Gaussian noise channel and Rayleigh fading channel, cannot perform well over onbody channel. In this paper, the DP-LDPC codes are redesigned for the JSCC system with new methods depending on the on-body channel characteristics. A protomatrix dimension-restrictive searching algorithm for DP-LDPC codes in the JSCC system is proposed according to the on-body channel bandwith and source statistic, which is effective to predesign the dimension of the code pair for a new JSCC system. In this way, the source-channel code rates are appropriately allocated to leave more source redundancy for improving the error floor. Moreover, the joint protomatrix is reconstructed into two kinds of compact structures by simplifying the edge linking relationships and modifying joint protograph extrinsic information transfer algorithm, which decreases the induction of searching entries to further accelerate the code searching speed. The searched code pairs show better bit-error ratio performances compared with existing DP-LDPC codes. The power consumption in the new joint coding system is lower than the separate coding system in WBAN on the physical layer.

关键词： joint source-channel coding DP-LDPC codes on-body channel M-ary DCSK modulation bit-error ratio

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Optimal Phase Transitions in Compressed Sensing

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IEEE TRANSACTIONS ON INFORMATION THEORY 2012年第10期58卷 6241-6263页

作者： Wu, Yihong Verdu, Sergio Univ Penn Wharton Sch Dept Stat Philadelphia PA 19104 USA Princeton Univ Dept Elect Engn Princeton NJ 08544 USA

Compressed sensing deals with efficient recovery of analog signals from linear encodings. This paper presents a statistical study of compressed sensing by modeling the input signal as an i.i.d. process with known distribution. Three classes of encoders are considered, namely optimal nonlinear, optimal linear, and random linear encoders. Focusing on optimal decoders, we investigate the fundamental tradeoff between measurement rate and reconstruction fidelity gauged by error probability and noise sensitivity in the absence and presence of measurement noise, respectively. The optimal phase-transition threshold is determined as a functional of the input distribution and compared to suboptimal thresholds achieved by popular reconstruction algorithms. In particular, we show that Gaussian sensing matrices incur no penalty on the phase-transition threshold with respect to optimal nonlinear encoding. Our results also provide a rigorous justification of previous results based on replica heuristics in the weak-noise regime.

关键词： Compressed sensing joint source-channel coding minimum mean-square error (MMSE) dimension phase transition random matrix Renyi information dimension Shannon theory

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Optimizing Low-Complexity Analog Mappings for Low-Power Sensors With Energy Scheduling Capabilities

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IEEE INTERNET OF THINGS JOURNAL 2022年第18期9卷 17387-17402页

作者： Mouris, Boules A. Stavrou, Photios A. Thobaben, Ragnar KTH Royal Inst Technol Sch Elect Engn & Comp Sci Div Informat Sci & Engn S-10044 Stockholm Sweden EURECOM F-06904 Sophia Antipolis France

Power consumption is a major challenge for a massive deployment of wireless sensors in Internet of Things (IoT) networks. This article studies the use of analog joint source-channel coding (AJSCC) mappings in low-power sensing schemes. In particular, we propose a novel triangular mapping geometry as a low-complexity dimension reduction mapping. The proposed triangular mapping is employed for analog compression of multiple sensor readings into one signal and, thus, limits the need for power-hungry analog-to-digital conversion and processing at the sensing nodes. A comprehensive performance analysis of the proposed triangular mapping in terms of the mean squared error (MSE) performance is provided analytically and verified numerically. The problem of mapping adaptation to different source distributions is also studied. Moreover, the proposed triangular mapping is adopted in an energy scheduling problem in which the sensing nodes schedule their use of the received powers at different time instants and adjust the mapping parameters accordingly with the goal of minimizing the sum distortion at the receiver. We present a fast low-complexity algorithm for optimal energy scheduling and verify its performance in comparison with commercial convex optimization solvers. It is shown that the proposed mapping provides a very good MSE performance compared to the AJSCC benchmarks despite having a much lower complexity circuit implementation.

关键词： Analog mappings energy harvesting joint source-channel coding low-power sensors

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Hybrid digital-analog (HDA) joint source-channel codes for broadcasting and robust communications

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IEEE TRANSACTIONS ON INFORMATION THEORY 2002年第5期48卷 1082-1102页

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

We consider the problem of transmitting a band-limited Gaussian source on an additive band-limited Gaussian noise channel. The well-known "threshold effect"dictates that the more powerful a code is, the more sensitive it is to the exact knowledge of the channel noise. A code is said to be robust if it is asymptotically optimal for a wide range of channel noise. Thus, robust codes have a "graceful degradation" characteristic and are free of the threshold effect. It is demonstrated that robust codes exist whenever the source and channel bandwidths are equal. In the unequal-bandwidth case, a collection of nearly robust joint source-channel codes Is constructed using a hybrid digital-analog (HEIA) coding technique. For designing nearly robust codes, a matched tandem code whose channel encoder's output is partially/fully matched to its input is proposed and the existence of an asymptotically optimal matched tandem code is shown. The nearly robust codes achieve the Shannon limit (theoretically optimum distortion) and have a less severe threshold effect. Finally, for the case of two different noise conditions, the distortion regions of these codes are determined.

关键词： Additive white Gaussian noise (AWGN) channel broadcasting joint source-channel coding memoryless Gaussian source robustness

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Wireless Deep Video Semantic Transmission

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IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS 2023年第1期41卷 214-229页

作者： Wang, Sixian Dai, Jincheng Liang, Zijian Niu, Kai Si, Zhongwei Dong, Chao Qin, Xiaoqi Zhang, Ping Beijing Univ Posts & Telecommun Key Lab Universal Wireless Commun Minist Educ Beijing 100876 Peoples R China Peng Cheng Lab Shenzhen 518066 Peoples R China Beijing Univ Posts & Telecommun State Key Lab Networking & Switching Technol Beijing 100876 Peoples R China

In this paper, we design a new class of high-efficiency deep joint source-channel coding methods to achieve end-to-end video transmission over wireless channels. The proposed methods exploit nonlinear transform and conditional coding architecture to adaptively extract semantic features across video frames, and transmit semantic feature domain representations over wireless channels via deep joint source-channel coding. Our framework is collected under the name deep video semantic transmission (DVST). In particular, benefiting from the strong temporal prior provided by the feature domain context, the learned nonlinear transform function becomes temporally adaptive, resulting in a richer and more accurate entropy model guiding the transmission of current frame. Accordingly, a novel rate adaptive transmission mechanism is developed to customize deep joint source-channel coding for video sources. It learns to allocate the limited channel bandwidth within and among video frames to maximize the overall transmission performance. The whole DVST design is formulated as an optimization problem whose goal is to minimize the end-to-end transmission rate-distortion performance under perceptual quality metrics or machine vision task performance metrics. Across standard video source test sequences and various communication scenarios, experiments show that our DVST can generally surpass traditional wireless video coded transmission schemes. The proposed DVST framework can well support future semantic communications due to its video content-aware and machine vision task integration abilities.

关键词： Semantic communications video transmission nonlinear transform joint source-channel coding rate-distortion

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Approximate Characterizations for the Gaussian source Broadcast Distortion Region

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IEEE TRANSACTIONS ON INFORMATION THEORY 2011年第1期57卷 124-136页

作者： Tian, Chao Diggavi, Suhas Shamai, Shlomo AT&T Labs Res Florham Pk NJ 07932 USA Univ Calif Los Angeles Dept Elect Engn Los Angeles CA 90095 USA Technion Israel Inst Technol Dept Elect Engn IL-32000 Haifa Israel

We consider the joint source-channel coding problem of sending a Gaussian source on a K-user Gaussian broadcast channel with bandwidth mismatch. A new outer bound to the achievable distortion region is derived using the technique of introducing more than one additional auxiliary random variable, which was previously used to derive sum-rate lower bound for the symmetric Gaussian multiple description problem. By combining this outer bound with the achievability result based on source-channel separation, we provide approximate characterizations of the achievable distortion region within constant multiplicative factors. Furthermore, we show that the results can be extended to general broadcast channels, and the performance of the source-channel separation based approach is also within the same constant multiplicative factors of the optimum.

关键词： Gaussian source joint source-channel coding squared error distortion

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