检索结果-内蒙古大学图书馆

joint Unitary Triangularization for MIMO Networks

IEEE TRANSACTIONS ON SIGNAL PROCESSING 2012年第1期60卷 326-336页

作者： Khina, Anatoly Kochman, Yuval Errez, Uri Tel Aviv Univ Dept Elect Engn Syst IL-69978 Tel Aviv Israel MIT Signals Informat & Algorithms Lab Cambridge MA 02139 USA

This paper considers communication networks where individual links can be described as those based on multiple-input multiple-output channels. Unlike orthogonal modulation methods (such as the singular-value decomposition), we allow interference between subchannels, which can be removed by the receivers via successive cancellation. The degrees of freedom earned by this relaxation are used for obtaining a basis, and corresponding decomposition, which are simultaneously good for more than one link. Specifically, we derive necessary and sufficient conditions for shaping the ratio vector of subchannel gains of two broadcast-channel receivers. We then apply this decomposition to two scenarios: First, in digital multicasting we present a practical capacity-achieving scheme which uses only scalar codes and linear processing. Then, we consider the joint source-channel problem of transmitting a Gaussian source over a two-user multiple-input multiple-output channel, where we show the existence of non-trivial cases, where the optimal distortion pair (which for high signal-to-noise ratios (SNRs) equals the optimal point-to-point distortions of the individual users) may be achieved by employing a hybrid digital-analog scheme over the induced equivalent channel. These scenarios demonstrate the advantage of choosing a modulation basis based upon multiple links in the network. Thus, we coin the approach "network modulation."

关键词： Broadcast channel GDFE generalized triangular decomposition (GTD) geometric mean decomposition GSVD joint source-channel coding MIMO multicasting multiplicative majorization

来源：评论

学校读者我要写书评

暂无评论

Excess Distortion Exponent Analysis for Semantic-Aware MIMO Communication Systems

引用

IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2023年第9期22卷 5927-5940页

作者： Shi, Yuxuan Shao, Shuo Wu, Yongpeng Zhang, Wenjun Xia, Xiang-Gen Xiao, Chengshan Shanghai Jiao Tong Univ Sch Cyber & Engn Shanghai 200240 Peoples R China ZGC Inst Ubiquitous X Innovat & Applicat Beijing 100876 Peoples R China Shanghai Jiao Tong Univ Dept Elect Engn Shanghai 200240 Peoples R China Univ Delaware Dept Elect & Comp Engn Newark DE 19716 USA Lehigh Univ Dept Elect & Comp Engn Bethlehem PA 18015 USA

In this paper, the analysis of excess distortion exponent for joint source-channel coding (JSCC) in semantic-aware communication systems is presented. By introducing an unobservable semantic source, we extend the classical results by Csiszar to semantic-aware communication systems. Both upper and lower bounds of the exponent for the discrete memoryless source-channel pair are established. Moreover, an extended achievable bound of the excess distortion exponent for MIMO systems is derived. Further analysis explores how the block fading and numbers of antennas influence the exponent of semantic-aware MIMO systems. Our results offer some theoretical bounds of error decay performance and can be used to guide future semantic communications with joint source-channel coding scheme.

关键词： Semantic-aware communication excess distortion exponent joint source-channel coding MIMO block fading channel

来源：评论

学校读者我要写书评

暂无评论

Tracking Unstable Autoregressive sources Over Discrete Memoryless channels

引用

IEEE TRANSACTIONS ON INFORMATION THEORY 2019年第12期65卷 8140-8163页

作者： Timo, Roy Vellami, Badri N. Grant, Alex Nguyen, Khoa D. Ericsson Res S-16440 Stockholm Sweden CEAS Elect Engn & Comp Syst Cincinnati OH 45221 USA Myriota Adelaide SA 5000 Australia Univ South Australia Sch Informat Technol & Math Sci Adelaide SA 5095 Australia

We consider the problem of tracking, in realtime, an unstable autoregressive (AR) source over a discrete memory-less channel (DMC). We present computable achievable bounds on the optimal tracking error for general DMCs, and we particularize these bounds to the binary erasure, packet erasure, and binary symmetric channels. The achievable bounds in this paper are proved using a partially separate source quantization and channel coding architecture. We do not use complete or strict separation in usual Shannon sense: 1) the quantiser's resolution is optimized against the error-correction capabilities of the channel code and the channel code is optimized against an AR Hamming distortion function matched to the source (a weighted Hamming distortion function that provides unequal error protection to different parts of the AR source). The achievability results for general DMCs are proved by combining the AR Hamming distortion function with new realtime (streaming) versions of the random coding union and dependence testing bounds. When applied to erasure channels, these general bounds combine with simple converses to demonstrate that the channel's cutoff rate plays an important role in realtime tracking.

关键词： joint source-channel coding sequential error-control coding auto-regressive (AR) sources error exponents

来源：评论

学校读者我要写书评

暂无评论

Scalable, error-resilient, and high-performance video communications in mobile wireless environments

引用

IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY 2001年第7期11卷 833-847页

作者： Vass, J Zhuang, S Zhuang, XH Eyeball Networks Inc Vancouver BC V7T 1A2 Canada Univ Calif Berkeley Dept Elect Engn & Comp Sci Berkeley CA 94720 USA Univ Missouri Dept Comp Engn & Comp Sci Columbia MO 65211 USA

A novel mobile communications system is proposed in the paper, which provides not only effective but also efficient video access for mobile users when communicating over low-bandwidth error-prone wireless links, The middleware implemented by a mobile proxy server at the mobile support station is designed for the seamless integration of mobile users with video servers, so the specific details of the underlying protocols and source/channel coding techniques are hidden to both the video server and mobile client. Based on the concept of application-level framing, the application (video codec in our case) plays a significant role in network communications that most of functionalities of the system are implemented as part of the application, As such, at the application layer, adaptive source- and channel-coding techniques are developed to jointly provide the user with the highest possible video quality, For efficient source coding, our high-performance low-complexity video-coding algorithm called a 3-D significance-linked connected component analysis (3D-SLCCA) is chosen, Due to its high robustness against channel-error propagation, 3D-SLCCA is well suited for wireless environments. For error-resilient channel coding, a multilayer transmission error-control mechanism is developed, Since there is no additional requirement imposed on either the mobile client or the video server, mobile users interact with the server in exactly the same way as stationary users, Extensive computer experiments demonstrate the effectiveness of the proposed system.

关键词： error-resilient coding joint source-channel coding mobile communications proxy server scalable coding SLCCA video coding

来源：评论

学校读者我要写书评

暂无评论

Gaussian State Amplification with Noisy Observations

引用

IEEE TRANSACTIONS ON INFORMATION THEORY 2015年第9期61卷 4587-4597页

作者： Tian, Chao Bandemer, Bernd Shamai (Shitz), Shlomo AT&T Labs Res Bedminster NJ 07921 USA Univ Calif San Diego Informat Theory & Applicat Ctr La Jolla CA 92093 USA Technion Israel Inst Technol Dept Elect Engn IL-32000 Haifa Israel

We consider the problem of channel state amplification in a Gaussian channel with additive Gaussian channel states, where the encoder observes noncausally a noisy version of these states. A complete characterization is provided for the minimum reconstruction distortion under a transmitter power constraint, and it is shown that a simple analog scheme with power control is optimal. More precisely, if the power available to the encoder is below certain threshold, the analog scheme using full power is optimal, however, when the power available to the encoder is above that threshold, analog transmission using only a fixed amount of the available power is optimal. Furthermore, the problem of simultaneous message transmission and Gaussian state amplification with noisy observations is studied, for which an inner bound and two nontrivial outer bounds to the optimal tradeoff between the transmission rate and the state reconstruction distortion are provided. The coding scheme underlying the inner bound combines analog signaling and Gelfand-Pinsker coding, where the latter deviates from the operating point of Costa's dirty paper coding. The first outer bound is obtained by extending the channel decomposition technique, while the second outer bound requires a strategic analysis of the covariance matrix of the relevant random variables.

关键词： joint source-channel coding channel with state

来源：评论

学校读者我要写书评

暂无评论

On the Design of Variable-Length Error-Correcting Codes

引用

IEEE TRANSACTIONS ON COMMUNICATIONS 2013年第9期61卷 3553-3565页

作者： Wu, Ting-Yi Chen, Po-Ning Alajaji, Fady Han, Yunghsiang S. Natl Chiao Tung Univ Dept Elect & Comp Engn Hsinchu 300 Taiwan Natl Chiao Tung Univ Ctr Informat & Commun Technol Hsinchu 300 Taiwan Queens Univ Dept Math & Stat Kingston ON K7L 3N6 Canada Natl Taiwan Univ Sci & Technol Dept Elect Engn Taipei 106 Taiwan

A joint source-channel coding problem that combines the efficient compression of discrete memoryless sources with their reliable communication over memoryless channels via binary prefix-free variable-length error-correcting codes (VLECs) is considered. Under a fixed free distance constraint, a priority-first search algorithm is devised for finding an optimal VLEC with minimal average codeword length. Two variations of the priority-first-search-based code construction algorithm are also provided. The first one improves the resilience of the developed codes against channel noise by additionally considering a performance parameter B-dfree without sacrificing optimality in average codeword length. In the second variation, to accommodate a large free distance constraint as well as a large source alphabet such as the 26-symbol English data source, the VLEC construction algorithm is modified with the objective of significantly reducing its search complexity while still yielding near-optimal codes. A low-complexity sequence maximum a posteriori (MAP) decoder for all VLECs (including our constructed optimal code) is then proposed under the premise that the receiver knows the number of codewords being transmitted. Simulations show that the realized optimal and suboptimal VLECs compare favorably with existing codes in the literature in terms of coding efficiency, search complexity and error rate performance.

关键词： joint source-channel coding variable-length codes error resilient data compression sequence maximum a posteriori decoding average codeword length symbol error rate

来源：评论

学校读者我要写书评

暂无评论

A Little Feedback Can Simplify Sensor Network Cooperation

引用

IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS 2010年第7期28卷 1159-1168页

作者： Sarwate, Anand Gastpar, Michael Univ Calif San Diego Calif Inst Telecommun & Informat Techol CALIT2 Informat Theory & Applicat Ctr San Diego CA 92103 USA Univ Calif Berkeley Dept Elect Engn & Comp Sci Berkeley CA 94720 USA Delft Univ Technol Dept Elect Engn Math & Comp Sci NL-2600 AA Delft Netherlands

Shannon's discovery of digital communication has shaped the architecture of virtually all communication systems in use today. The digital communication paradigm is built around the notion of bits and uses careful coding to deliver bits reliably end-to-end. It has been shown that this architectural principle can lead to a very significant performance penalty in wireless sensor networks. For a limited class of network scenarios, it was shown that optimal architectures are analog in nature, simple and scalable. In this paper, we show that more generally, simple analog architectures crucially depend on feedback to the sensors. Interesting questions then concern the amount of feedback needed and the resulting trade-off with performance. This paper provides rules-of-thumb for the selection of the number of feedback bits.

关键词： joint source-channel coding fading sensor networks data fusion feedback

来源：评论

学校读者我要写书评

暂无评论

Zero-Delay Sequential Transmission of Markov sources Over Burst Erasure channels

引用

IEEE TRANSACTIONS ON INFORMATION THEORY 2014年第8期60卷 4584-4613页

作者： Etezadi, Farrokh Khisti, Ashish Trott, Mitchell Univ Toronto Toronto ON M5S 1A1 Canada HP Labs Palo Alto CA 94304 USA

A setup involving zero-delay sequential transmission of a vector Markov source over a burst erasure channel is studied. A sequence of source vectors is compressed in a causal fashion at the encoder, and the resulting output is transmitted over a burst erasure channel. The destination is required to reconstruct each source vector with zero-delay, but those source sequences that are observed either during the burst erasure, or in the interval of length W following the burst erasure need not be reconstructed. The minimum achievable compression rate is called the rate-recovery function. We assume that each source vector is independent identically distributed (i.i.d.) across the spatial dimension and is sampled from a stationary, first-order Markov process across the temporal dimension. For discrete sources, the case of lossless recovery is considered, and upper and lower bounds on the rate-recovery function are established. Both these bounds can be expressed as the rate for predictive coding, plus a term that decreases at least inversely with the recovery window length W. For Gauss-Markov sources and a quadratic distortion measure, upper and lower bounds on the minimum rate are established when W = 0. These bounds are shown to coincide in the high resolution limit. Finally, another setup involving i.i.d. Gaussian sources is studied and the rate-recovery function is completely characterized in this case.

关键词： joint source-channel coding distributed source coding Gauss-Markov sources Kalman filter burst erasure channels multi-terminal information theory rate-distortion theory

来源：评论

学校读者我要写书评

暂无评论

Sending a Bivariate Gaussian source Over a Gaussian MAC With Unidirectional Conferencing Encoders

引用

IEEE TRANSACTIONS ON INFORMATION THEORY 2016年第3期62卷 1296-1311页

作者： Bross, Shraga I. Laufer, Yaron Bar Ilan Univ Dept Engn IL-52900 Ramat Gan Israel

We consider the transmission of a memoryless bivariate Gaussian source over a two-user additive Gaussian multiple-access channel with unidirectional conferencing encoders. Here, prior to each transmission block, Encoder 1, which observes the first source component, is allowed to communicate with Encoder 2, which observes the second source component, via a unidirectional noise-free bit-pipe of given capacity. The main results of this paper are sufficient conditions and a necessary condition for the achievability of a distortion pair expressed as a function of the channel SNR and of the source correlation. The main sufficient condition is obtained by an extension of the vector-quantizer scheme suggested by Lapidoth-Tinguely, for the case without conferencing, to the case with unidirectional conference. In the high-SNR regime, and when the capacity of the conference channel is unlimited, these necessary and sufficient conditions are shown to agree. We evaluate the precise high-SNR asymptotics for a subset of distortion pairs when the capacity of the conference channel is unlimited in which case we show that a separation-based scheme attains these optimal distortion pairs. However, with symmetric average-power constraints and fixed conferencing capacity, at high-SNR, the latter separation-based scheme is shown to be suboptimal.

关键词： joint source-channel coding Gaussian multiple-access channel unidirectional conferencing encoders

来源：评论

学校读者我要写书评

暂无评论

joint source and channel decoding of compressed still images

引用

SIGNAL PROCESSING-IMAGE COMMUNICATION 1999年第3期15卷 217-229页

作者： Xu, W Hagenauer, J Hollmann, J Tech Univ Munich Lehrstuhl Nachrichtentech D-80290 Munich Germany

A joins source-channel decoding approach is described, which utilizes the residual redundancy in the bit stream of a source-coded image by employing a modified APRI-SOVA (a priori soft-output Viterbi algorithm) at the channel decoder. The source coders used are the nonadaptive discrete cosine transform (]DCT) coding and subband coding with Lloyd-Max quantization. The log-likelihood ratio describing the a priori information is linearized. The reliability of the current bit is computed as a proper linear combination of the soft values characterizing statistical dependency of the zeroth order (probability of 1's or 0's) and the first order (bit correlation among neighboring samples). Substantial subjective and objective performance gains can be obtained by using this method. It is demonstrated that especially in a noisy environment, it may be better to keep the residual redundancy in the data and use it at the receiver side in order to achieve a more reliable decoding, rather than to further remove it by using a variable length coding. The trade-off between the allocation of bits for source and channel coding is also addressed. (C) 1999 Elsevier Science B.V. All rights reserved.

关键词： joint source-channel coding DCT coding subband coding soft-output viterbi algorithm

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：