检索结果-内蒙古大学图书馆

Symmetric Semideterministic Relay Networks With No Interference at the Relays

IEEE TRANSACTIONS ON INFORMATION THEORY 2011年第9期57卷 5673-5681页

作者： Ghabeli, Leila Aref, Mohammad Reza Sharif Univ Technol Informat Syst & Secur Lab ISSL Dept Elect Engn Tehran Iran

A symmetric semideterministic relay network is introduced, generalizing Aref networks. In the considered model, there is no interference at the relays, but the links from the source and the relays to the sink are interfering and nondeterministic. An achievable rate is determined for an arbitrary number of relays, based on symmetric relaying and simultaneous partial and backward decoding at the sink. The information expressions of the achievable rate match those of the standard cut-set bound, but the set of probability distributions is substantially different. We also study a wireless example of the defined network where nondeterministic links are replaced with fading AWGN channels, and obtain its ergodic capacity with phase fading when phase information is locally available at the sink.

关键词： Aref networks capacity semideterministic relay networks simultaneous decoding symmetric relaying

来源：评论

学校读者我要写书评

暂无评论

On the Optimal Achievable Rates for Linear Computation With Random Homologous Codes

引用

IEEE TRANSACTIONS ON INFORMATION THEORY 2020年第10期66卷 6200-6221页

作者： Sen, Pinar Lim, Sung Hoon Kim, Young-Han Univ Calif San Diego Dept Elect & Comp Engn La Jolla CA 92093 USA Hallym Univ Sch Software Chunchon 24252 South Korea

The problem of computing a linear combination of sources over a multiple access channel is studied. Inner and outer bounds on the optimal tradeoff between the communication rates are established when encoding is restricted to random ensembles of homologous codes, namely, structured nested coset codes from the same generator matrix and individual shaping functions, but when decoding is optimized with respect to the realization of the encoders. For the special case in which the desired linear combination is "matched" to the structure of the multiple access channel in a natural sense, these inner and outer bounds coincide. This result indicates that most, if not all, coding schemes for computation in the literature that rely on random construction of nested coset codes cannot be improved by using more powerful decoders such as the maximum likelihood decoder. The proof techniques are adapted to characterize the rate region for broadcast channels achieved by Marton's (random) coding scheme under maximum likelihood decoding. By generalizing some of the techniques, a single-letter outer bound for the capacity region of the computation problem is presented and compared with the inner bound achieved by homologous codes.

关键词： Maximum likelihood decoding Receivers Lattices Generators Linear codes Multiple access channel broadcast channel structured coding linear code maximum likelihood decoding simultaneous decoding Marton's coding

来源：评论

学校读者我要写书评

暂无评论

Capacity theorems for the "Z" channel

引用

IEEE TRANSACTIONS ON INFORMATION THEORY 2007年第4期53卷 1348-1365页

作者： Chong, Hon-Fah Motani, Mehul Garg, Hari Krishna Natl Univ Singapore Dept Elect & Comp Engn Singapore 117576 Singapore

We consider the two-user "Z" channel (ZC), where there are two senders and two receivers. One of the senders transmits information to its intended receiver (without interfering with the unintended receiver), while the other sender transmits information to both receivers. The complete characterization of the discrete memoryless ZC remains unknown to date. For the Gaussian ZC, the capacity has only been established for a crossover link gain of 1. In this work, we study both the discrete memoryless ZC and the Gaussian ZC. We first establish achievable rates for the general discrete memoryless ZC. The coding strategy uses rate-splitting and superposition coding at the sender with information for both receivers. At the receivers, we use joint decoding. We then specialize the rates obtained to two different types of degraded discrete memoryless ZCs and also derive respective outer bounds to their capacity regions. We show that as long as a certain condition is satisfied, the achievable rate region is the capacity region for one type of degraded discrete memoryless ZC. The results are then extended to the two-user Gaussian ZC with different crossover link gains. We determine an outer bound to the capacity region of the Gaussian ZC with strong crossover link gain and establish the capacity region for moderately strong crossover link gain.

关键词： Gaussian "Z" channel (ZC) rate-splitting simultaneous decoding superposition coding "Z" channel (ZC)

来源：评论

学校读者我要写书评

暂无评论

Interference channels with common information

引用

IEEE TRANSACTIONS ON INFORMATION THEORY 2008年第1期54卷 171-187页

作者： Jiang, Jinhua Xin, Yan Garg, Hari Krishna Natl Univ Singapore Dept Elect & Comp Engn Singapore 117576 Singapore

In this paper, the interference channel with common information (ICC), in which two senders need deliver not only private messages but also certain common messages to their corresponding receivers, is investigated. An achievable rate region for such a channel is obtained by applying a superposition coding scheme that consists of successive encoding and simultaneous decoding. It is shown that the derived achievable rate region includes or extends several existing results for the interference channels with or without common information. The rate region is then specialized to a class of ICCs in which one sender has no private information to transmit, and a class of deterministic interference channels with common information (DICCs). In particular, the derived rate region is found to be the capacity region for this class of DICCs. Last, the achievable rate region derived for the discrete memoryless ICC is extended to the Gaussian case, in which a numerical example is provided to illustrate the improvement of our rate region over an existing result.

关键词： capacity region common information interference channel multiple-access channel (MAC) simultaneous decoding superposition coding

来源：评论

学校读者我要写书评

暂无评论

Sliding-Window Superposition Coding: Two-User Interference Channels

引用

IEEE TRANSACTIONS ON INFORMATION THEORY 2020年第6期66卷 3293-3316页

作者： Wang, Lele Kim, Young-Han Chen, Chiao-Yi Park, Hosung Sasoglu, Eren Univ British Columbia Dept Elect & Comp Engn Vancouver BC V6T 1Z4 Canada Univ Calif San Diego Dept Elect & Comp Engn San Diego CA 92093 USA Broadcom Ltd Sunnyvale CA 94086 USA Chonnam Natl Univ Sch Elect & Comp Engn Gwangju 61186 South Korea Apple Inc Cupertino CA 95014 USA

A low-complexity coding scheme is developed to achieve the rate region of maximum likelihood decoding for interference channels. As in the classical rate-splitting multiple access scheme by Grant, Urbanke, and Whiting, the proposed coding scheme uses superposition of multiple codewords with successive cancellation decoding, which can be implemented using standard point-to-point encoders and decoders. Unlike rate-splitting multiple access, which is not rate-optimal for multiple receivers, the proposed coding scheme transmits codewords over multiple blocks in a staggered manner and recovers them successively over sliding decoding windows, achieving the single-stream optimal rate region as well as the more general Han-Kobayashi inner bound for the two-user interference channel. The feasibility of this scheme in practice is verified by implementing it using commercial channel codes over the two-user Gaussian interference channel.

关键词： Maximum likelihood decoding Encoding Interference channels Receivers Modulation Coded modulation coding technique interference management simultaneous decoding

来源：评论

学校读者我要写书评

暂无评论

The Finite State MAC With Cooperative Encoders and Delayed CSI

引用

IEEE TRANSACTIONS ON INFORMATION THEORY 2014年第10期60卷 6181-6203页

作者： Goldfeld, Ziv Permuter, Haim H. Zaidel, Benjamin M. Ben Gurion Univ Negev Dept Elect & Comp Engn IL-84110 Beer Sheva Israel Bar Ilan Univ Fac Engn IL-52900 Ramat Gan Israel

In this paper, we consider the finite-state multiple access channel (MAC) with partially cooperative encoders and delayed channel state information (CSI). Here, partial cooperation refers to the communication between the encoders via finite-capacity links. The channel states are assumed to be governed by a Markov process. Full CSI is assumed at the receiver, while at the transmitters, only delayed CSI is available. The capacity region of this channel model is derived by first solving the case of the finite-state MAC with a common message. Achievability for the latter case is established using the notion of strategies, however, we show that optimal codes can be constructed directly over the input alphabet. This results in a single codebook construction that is then leveraged to apply simultaneous joint decoding. simultaneous decoding is crucial here because it circumvents the need to rely on the capacity region's corner points, a task that becomes increasingly cumbersome with the growth in the number of messages to be sent. The common message result is then used to derive the capacity region for the case with partially cooperating encoders. Next, we apply this general result to the special case of the Gaussian vector MAC with diagonal channel transfer matrices, which is suitable for modeling, e. g., orthogonal frequency division multiplexing-based communication systems. The capacity region of the Gaussian channel is presented in terms of a convex optimization problem that can be solved efficiently using numerical tools. The region is derived by first presenting an outer bound on the general capacity region and then suggesting a specific input distribution that achieves this bound. Finally, numerical results are provided that give valuable insight into the practical implications of optimally using conferencing to maximize the transmission rates.

关键词： Capacity region common message convex optimization cooperative encoders delayed CSI diagonal vector gaussian multiple-access channel finite-state channel multiple-access channel simultaneous decoding strategy letters

来源：评论

学校读者我要写书评

暂无评论

Optimal Achievable Rates for Interference Networks With Random Codes

引用

IEEE TRANSACTIONS ON INFORMATION THEORY 2015年第12期61卷 6536-6549页

作者： Bandemer, Bernd El Gamal, Abbas Kim, Young-Han Univ Calif San Diego Informat Theory & Applicat Ctr La Jolla CA 92093 USA Stanford Univ Dept Elect Engn Stanford CA 94305 USA Univ Calif San Diego Dept Elect & Comp Engn La Jolla CA 92093 USA

The optimal rate region for interference networks is characterized when encoding is restricted to random code ensembles with superposition coding and time sharing. A simple simultaneous nonunique decoding rule, under which each receiver decodes for the intended message as well as the interfering messages, is shown to achieve this optimal rate region regardless of the relative strengths of signal, interference, and noise. This result implies that the Han-Kobayashi bound, the best known inner bound on the capacity region of the two-user pair interference channel, cannot be improved merely by using the optimal maximum likelihood decoder.

关键词： Han-Kobayashi bound interference network maximum likelihood decoding network information theory random code ensemble superposition coding simultaneous decoding

来源：评论

学校读者我要写书评

暂无评论

Capacity Region of the Finite State MAC with Cooperative Encoders and Delayed CSI

Capacity Region of the Finite State MAC with Cooperative Enc...

引用

IEEE International Symposium on Information Theory

作者： Goldfeld, Ziv Permuter, Haim H. Zaidel, Benjamin M. Ben Gurion Univ Negev IL-84105 Beer Sheva Israel

ISBN: (纸本)9781467325790

In this paper, a single-letter characterization for the capacity region of finite-state multiple access channels (MACs) with partially cooperative encoders is derived. Partial cooperation here is in the sense that the encoders communicate with each other through finite-capacity links. The channel states are assumed to be governed by a Markov processes. Full channel state information (CSI) is assumed at the receiver, while only delayed CSI is available at transmitters. The capacity region is derived by first solving the case of finite-state multiple access channels with common message, using rate splitting, multiplexing and simultaneous decoding in order to establish the achievability. The common message result is then used to derive the capacity region of the partially cooperative encoders case. Finally, we apply this result in order to obtain the capacity region for a finite-state Gaussian MAC with partially cooperative encoders.

关键词： Capacity region Common message Cooperative encoders Delayed CSI Finite-state channel Fourier-Motzking elimination Gaussian multiple-access channel Multiple-access channel simultaneous decoding

来源：评论

学校读者我要写书评

暂无评论

SimulLR: simultaneous Lip Reading Transducer with Attention-Guided Adaptive Memory 21

SimulLR: Simultaneous Lip Reading Transducer with Attention-...

引用

29th ACM International Conference on Multimedia (MM)

作者： Lin, Zhijie Zhao, Zhou Li, Haoyuan Liu, Jinglin Zhang, Meng Zeng, Xingshan He, Xiaofei Zhejiang Univ Hangzhou Peoples R China Huawei Noahs Ark Lab Hong Kong Peoples R China

ISBN: (纸本)9781450386517

Lip reading, aiming to recognize spoken sentences according to the given video of lip movements without relying on the audio stream, has attracted great interest due to its application in many scenarios. Although prior works that explore lip reading have obtained salient achievements, they are all trained in a non-simultaneous manner where the predictions are generated requiring access to the full video. To breakthrough this constraint, we study the task of simultaneous lip reading and devise SimulLR, a simultaneous lip Reading transducer with attention-guided adaptive memory from three aspects: (1) To address the challenge of monotonic alignments while considering the syntactic structure of the generated sentences under simultaneous setting, we build a transducer-based model and design several effective training strategies including CTC pre-training, model warm-up and curriculum learning to promote the training of the lip reading transducer. (2) To learn better spatio-temporal representations for simultaneous encoder, we construct a truncated 3D convolution and time-restricted self-attention layer to perform the frame-to-frame interaction within a video segment containing fixed number of frames. (3) The history information is always limited due to the storage in real-time scenarios, especially for massive video data. Therefore, we devise a novel attention-guided adaptive memory to organize semantic information of history segments and enhance the visual representations with acceptable computationaware latency. The experiments show that the SimulLR achieves the translation speedup 9.10x compared with the state-of-the-art non-simultaneous methods, and also obtains competitive results, which indicates the effectiveness of our proposed methods.

关键词： visual understanding lip reading simultaneous decoding memory

来源：评论

学校读者我要写书评

暂无评论

simultaneous real-time monitoring of multiple cortical systems

引用

JOURNAL OF NEURAL ENGINEERING 2014年第5期11卷 056001-056001页

作者： Gupta, Disha Hill, N. Jeremy Brunner, Peter Gunduz, Aysegul Ritaccio, Anthony L. Schalk, Gerwin New York State Dept Hlth Wadsworth Ctr Albany NY 12237 USA Albany Med Coll Dept Neurol Albany NY USA Burke Cornell Med Res Inst Early Brain Injury Recovery Program White Plains NY USA Univ Florida J Crayton Pruitt Family Dept Biomed Engn Gainesville FL USA SUNY Albany Dept Biomed Sci Albany NY USA Helen Hayes Hosp Translat Neurol Res Lab W Haverstraw NY USA

Objective. Real-time monitoring of the brain is potentially valuable for performance monitoring, communication, training or rehabilitation. In natural situations, the brain performs a complex mix of various sensory, motor or cognitive functions. Thus, real-time brain monitoring would be most valuable if (a) it could decode information from multiple brain systems simultaneously, and (b) this decoding of each brain system were robust to variations in the activity of other (unrelated) brain systems. Previous studies showed that it is possible to decode some information from different brain systems in retrospect and/or in isolation. In our study, we set out to determine whether it is possible to simultaneously decode important information about a user from different brain systems in real time, and to evaluate the impact of concurrent activity in different brain systems on decoding performance. Approach. We study these questions using electrocorticographic signals recorded in humans. We first document procedures for generating stable decoding models given little training data, and then report their use for offline and for real-time decoding from 12 subjects (six for offline parameter optimization, six for online experimentation). The subjects engage in tasks that involve movement intention, movement execution and auditory functions, separately, and then simultaneously. Main results. Our real-time results demonstrate that our system can identify intention and movement periods in single trials with an accuracy of 80.4% and 86.8%, respectively (where 50% would be expected by chance). simultaneously, the decoding of the power envelope of an auditory stimulus resulted in an average correlation coefficient of 0.37 between the actual and decoded power envelopes. These decoders were trained separately and executed simultaneously in real time. Significance. This study yielded the first demonstration that it is possible to decode simultaneously the functional activity of multiple

关键词： electrocorticography movement intention auditory processing real-time decoding simultaneous decoding

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：