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Strong Coordination Over Noisy channels

IEEE TRANSACTIONS ON INFORMATION THEORY 2021年第5期67卷 2716-2738页

作者： Obead, Sarah A. Vellambi, Badri N. Kliewer, Joerg New Jersey Inst Technol Dept Elect & Comp Engn Newark NJ 07102 USA Univ Cincinnati Dept Elect Engn & Comp Sci Cincinnati OH 45221 USA

We study the problem of strong coordination of the actions of two nodes X and Y that communicate over a discrete memoryless channel (DMC) such that the actions follow a prescribed joint probability distribution. We propose two novel random coding schemes and a polar coding scheme for this noisy strong coordination problem, and derive inner and outer bounds for the respective strong coordination capacity region. The first scheme is a joint coordination-channel encoding scheme that utilizes the randomness provided by the communication channel to reduce the amount of local randomness required to generate the sequence of actions at Node Y. Based on this random coding scheme, we provide a characterization of the capacity region for a special case of the noisy strong coordination setup, namely, when the DMC is a deterministic channel. The second scheme exploits separate coordination and channel encoding where local randomness is extracted from the channel after decoding. Moreover, by leveraging the random coding results for this problem, we present an example in which the proposed joint encoding scheme is able to strictly outperform the separate encoding scheme in terms of achievable communication rate for the same amount of injected randomness into both systems. Thus, we establish the sub-optimality of the separation of strong coordination and channel encoding with respect to the communication rate over the DMC in this problem. Finally, the third scheme is a joint coordination-channel polar coding scheme for strong coordination. We show that polar codes are able to achieve the established inner bound to the strong noisy coordination capacity region and thus provide a constructive alternative to a random coding proof. Our polar coding scheme also offers a constructive solution to a channel simulation problem where a DMC and shared randomness are employed together to simulate another DMC.

关键词： Strong coordination joint source-channel coding channel resolvability superposition coding polar codes

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Wideband User Grouping for Uplink Multiuser mmWave MIMO Systems With Hybrid Combining

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IEEE ACCESS 2021年 9卷 41360-41372页

作者： Perez-Adan, Darian Fresnedo, Oscar Gonzalez-Coma, Jose P. Castedo, Luis Univ A Coruna Dept Comp Engn La Coruna 15071 Spain Univ A Coruna Ctr Res Informat & Commun Technol CITIC La Coruna 15071 Spain Spanish Naval Acad Def Univ Ctr Marin 36920 Spain

Analog-digital hybrid precoding and combining schemes constitute an interesting approach to millimeter-wave (mmWave) multiple-input multiple-output (MIMO) systems due to the low hardware complexity and/or low power required for its deployment. However, the design of the hybrid precoders and combiners of a wideband multiuser (MU) mmWave MIMO system is challenging because the signal processing in the analog domain is constrained to be frequency flat. Furthermore, the number of radio frequency (RF) chains limits the number of individual streams that a common base station (BS) can simultaneously serve. This work jointly addresses the user scheduling, the user precoder design, and the BS hybrid combining design for the uplink of wideband MU mmWave MIMO systems. On the one hand, user precoding and BS hybrid combining are jointly designed to minimize the impact of having frequency-flat RF components. On the other hand, a number of users larger than the number of RF chains are served at the BS by employing a distributed quantizer linear coding (DQLC)-based non-orthogonal multiple access (NOMA) scheme. The use of this encoding strategy also allows exploiting the spatial correlation between the source information. Simulation results show remarkable performance gains of the proposed approaches for wideband mmWave MIMO hardware-constrained systems.

关键词： User scheduling wideband mmWave multiuser communications non-orthogonal multiple access joint source-channel coding

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joint source-channel Distortion Modeling for MPEG-4 Video

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IEEE TRANSACTIONS ON IMAGE PROCESSING 2009年第1期18卷 90-105页

作者： Sabir, Muhammad Farooq Heath, Robert W., Jr. Bovik, Alan Conrad K WILL Corp San Jose CA 95134 USA Univ Texas Austin Dept Elect & Comp Engn Wireless Networking & Commun Grp Austin TX 78712 USA

Multimedia communication has become one of the main applications in commercial wireless systems. Multimedia sources, mainly consisting of digital images and videos, have high bandwidth requirements. Since bandwidth is a valuable resource, it is important that its use should be optimized for image and video communication. Therefore, interest in developing new joint source-channel coding (JSCC) methods for image and video communication is increasing. Design of any JSCC scheme requires an estimate of the distortion at different source coding rates and under different channel conditions. The common approach to obtain this estimate is via simulations or operational rate-distortion curves. These approaches, however, are computationally intensive and, hence, not feasible for real-time coding and transmission applications. A more feasible approach to estimate distortion is to develop models that predict distortion at different source coding rates and under different channel conditions. Based on this idea, we present a distortion model for estimating the distortion due to quantization and channel errors in MPEG-4 compressed video streams at different source coding rates and channel bit error rates. This model takes into account important aspects of video compression such as transform coding, motion compensation, and variable length coding. Results show that our model estimates distortion within 1.5 dB of actual simulation values in terms of peak-signal-to-noise ratio.

关键词： Distortion modeling joint source-channel coding MPEG-4 quality assessment video communication

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Digital-Analog Transmission Framework for Task-Oriented Semantic Communications

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IEEE NETWORK 2024年第6期38卷 81-88页

作者： Fu, Yuzhou Cheng, Wenchi Zhang, Wei Wang, Jingqing Xidian Univ Sch Telecommun Engn Xian 710071 Peoples R China Univ New South Wales Sch Elect Engn & Telecommun Sydney NSW 2052 Australia

Task-Oriented Semantic Communication (TOSC) has been considered as a new communication paradigm to serve various smart devices that depend on Artificial Intelligence (AI) tasks in future wireless networks. The existing TOSC frameworks rely on the Neural Network (NN) model to extract the semantic feature from the source data. The semantic feature, constituted by analog vectors of a lower dimensionality relative to the original source data, reserves the meaning of the source data. By conveying the semantic feature, TOSCs can significantly reduce the amount of data transmission while ensuring the correct execution of the AI-driven downstream task. However, standardized wireless networks depend on digital signal processing for data transmission, yet they necessitate the conveyance of semantic features that are inherently analog. Although existing TOSC frameworks developed the Deep Learning (DL) based analog approach or conventional digital approach to transmit the semantic feature, but there are still many challenging problems to urgently be solved in actual deployment. In this article, we first propose several challenging issues associated with the development of the TOSC framework in the standardized wireless network. Then, we develop a Digital-Analog transmission framework based TOSC (DA-TOSC) to resolve these challenging issues. Future research directions are discussed to further improve the DA-TOSC.

关键词： Semantics Task analysis Feature extraction Wireless networks Artificial neural networks Digital-analog conversion Decoding Task-oriented semantic communication digital-analog transmission joint source-channel coding resource allocation

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Robust vector quantizer design using self-organizing neural networks

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SIGNAL PROCESSING 2000年第7期80卷 1289-1298页

作者： Azami, SBZ Feng, G Ecole Natl Super Telecommun F-75634 Paris 13 France

In this paper we propose a new method to design vector quantizers for noisy channels. Self-organizing neural networks are known for their efficiency in voice and image data compression;we use self-organizing algorithm to create a topological similarity between the input space and the index space. This similarity reduces the effect of channel noise because any single bit error in a transmitted index will be translated to a close codevector in the input space which yields relatively small distortion. For an 8-bit vector quantizer, the proposed system resulted in 4.59 dB spectral distortion in a highly noisy channel while a simple LEG, LEG with splitting and 2-D self-organizing map (SOM) resulted in 5.96, 5.46 and 5.02 dB of distortion, respectively. (C) 2000 Published by Elsevier Science B.V. All rights reserved.

关键词： robust vector quantization self-organizing neural networks competitive learning index assignment hamming distance vocoder joint source-channel coding

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Distortion bounds for broadcasting with bandwidth expansion

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IEEE TRANSACTIONS ON INFORMATION THEORY 2006年第8期52卷 3778-3788页

作者： Reznic, Zvi Feder, Meir Zamir, Ram Tel Aviv Univ Dept Elect Engn Syst IL-69978 Ramat Aviv Israel

We consider the problem of broadcasting a single Gaussian source to two listeners over a Gaussian, broadcast channel, with rho channel uses per source sample, where rho > 1. A distortion pair (D-1, D-2) is said to be achievable if one can simultaneously achieve a mean-squared error (MSE) D-1 at receiver 1 and D-2 at receiver 2. The main result of this correspondence is an outer bound for the set of all achievable distortion pairs. That is, we find necessary conditions under which (D, 1 D2) is achievable. We then apply this result to the problem of point-to-point transmission over a Gaussian channel with unknown signal-to-noise ratio (SNR) and rho > 1. We show that if a system must be optimal at a certain SNRmin, then, asymptotically, the system distortion cannot decay faster than O(1/SNR). As for achievability, we show that a previously reported scheme, due to Mittal and Phamdo (2002), is optimal at high SNR. We introduce two new schemes for broadcasting with bandwidth expansion, combining digital and analog transmissions. We finally show how a system with a partial feedback, returning from the bad receiver to the transmitter and to the good receiver, achieves a distortion pair that lies on the outer bound derived here.

关键词： distortion region joint source-channel coding lossy broadcasting

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Memory efficient adaptation of vector quantizers to time-varying channels

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SIGNAL PROCESSING 2003年第7期83卷 1519-1528页

作者： Görtz, N Kliewer, J Tech Univ Munich Inst Commun Engn LNT D-80290 Munich Germany Univ Kiel Inst Circuits & Syst Theory D-24143 Kiel Germany

channel-optimized vector quantization (COVQ) is approximated by the novel channel-adaptive scaled vector quantization (CASVQ). This new method uses a reference codebook that is optimal for one specific channel condition. However, for a bit-error rate being different from the design assumption for the reference codebook, all codevectors are scaled by a common factor, which depends on the channel condition. It is shown by simulations that a performance close to that of COVQ can be achieved in many practically important situations. Without a significant increase in complexity, the new CASVQ-scheme can be adapted to time-varying channels by adjusting the scaling factor to the current bit-error probability. Another advantage is that only one codebook needs to be stored for all error probabilities, while for COVQ either the performance degrades significantly due to channel mismatch, or a large set of codebooks, must be available at the encoder and the decoder. (C) 2003 Elsevier Science B.V. All rights reserved.

关键词： joint source-channel coding channel-optimized vector quantization time-varying channels complexity and memory requirements

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Reliability Function for Streaming Over a DMC With Feedback

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IEEE TRANSACTIONS ON INFORMATION THEORY 2023年第4期69卷 2165-2192页

作者： Guo, Nian Kostina, Victoria CALTECH Dept Elect Engn Pasadena CA 91125 USA

Conventionally, posterior matching is investigated in channel coding and block encoding contexts - the source symbols are equiprobably distributed and are entirely known by the encoder before the transmission. In this paper, we consider a streaming source, whose symbols progressively arrive at the encoder at a sequence of deterministic times. We derive the joint source-channel coding (JSCC) reliability function for streaming over a discrete memoryless channel (DMC) with feedback. We propose a novel instantaneous encoding phase that operates during the symbol arriving period and achieves the JSCC reliability function for streaming when followed by a block encoding scheme that achieves the JSCC reliability function for a classical source whose symbols are fully accessible before the transmission. During the instantaneous encoding phase, the evolving message alphabet is partitioned into groups whose priors are close to the capacity-achieving distribution, and the encoder determines the group index of the actual sequence of symbols arrived so far and applies randomization to exactly match the distribution of the transmitted index to the capacity-achieving one. Surprisingly, the JSCC reliability function for streaming is equal to that for a fully accessible source, implying that the knowledge of the entire symbol sequence before the transmission offers no advantage in terms of the reliability function. For streaming over a symmetric binary-input DMC, we propose a one-phase instantaneous small-enough difference (SED) code that not only achieves the JSCC reliability function, but also, thanks to its single-phase time-invariant coding rule, can be used to stabilize an unstable linear system over a noisy channel. For equiprobably distributed source symbols, we design low complexity algorithms to implement both the instantaneous encoding phase and the instantaneous SED code. The algorithms group the source sequences into sets we call types, which enable the encoder and the de

关键词： channels with feedback reliability function joint source-channel coding variable-length codes streaming causal coding posterior matching anytime codes control over noisy channels

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source-Interference Recovery Over Broadcast channels: Asymptotic Bounds and Analog Codes

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IEEE TRANSACTIONS ON COMMUNICATIONS 2016年第8期64卷 3406-3418页

作者： Abou Saleh, Ahmad Alajaji, Fady Chan, Wai-Yip Queens Univ Dept Elect & Comp Engn Kingston ON K7L 3N6 Canada Queens Univ Dept Math & Stat Kingston ON K7L 3N6 Canada

We consider the problem of joint recovery of a bivariate Gaussian source and of interference over the two-user Gaussian degraded broadcast channel in the presence of common interference. The interference, that is available non-causally at the encoder, is assumed to be Gaussian and correlated to the sources. The tradeoff between the distortion of the sources and the interference estimation error is studied;information-theoretic outer and inner bounds based on ideas from rate-distortion theory and hybrid coding are derived, respectively. More precisely, the outer bound is found by assuming additional knowledge at each user;the inner bound, however, is obtained by analyzing the distortion of a layered hybrid scheme based on proper power splitting, Costa and Wyner-Ziv coding. Low delay and complexity coding schemes based on analog mapping are next proposed. More specifically, parametric mappings based on linear and sawtooth curves are studied and optimized by minimizing an upper bound on the system's distortion;nonparametric mappings based on joint optimization between the encoder and the decoder using an iterative algorithm are designed. Numerical results show that for the special cases that are previously considered by Abou Saleh et al. (with no fading), the derived outer bound is tighter and the proposed hybrid scheme has a lower complex structure with no loss in performance. In addition, the proposed low delay nonlinear schemes outperform the linear scheme and perform relatively close to the inner bound under certain system settings.

关键词： joint source-channel coding distortion region correlated interference dirty paper coding Shannon-Kotel'nikov mapping low delay coding degraded broadcast channels

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Image transmission over the polya channel via channel optimized quantization

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IEEE TRANSACTIONS ON SIGNAL PROCESSING 2005年第2期53卷 728-733页

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

We introduce two progressive methods for image transmission over binary channels with additive bursty noise modeled by the finite-memory Polya (contagion) channel. The methods, which are based on channel-optimized scalar quantization (COSQ) of the wavelet transform coefficients, exploit channel memory to offer superior performance over a number of more complex systems designed for the fully interleaved channel.

关键词： channel optimized scaler quantization channels with memory convolutional codes joint source-channel coding subband coding

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